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Why have SVG images not yet replaced PNG on the web?

76 points by seky 13y ago

ris 13y ago
Answer: because there are plenty of things you simply can't express in SVG with its current level of support across browsers. e.g. no blend mode except "normal" really works reliably across browsers yet. And just a reminder: it's 2013, everyone. Next question...
- andrewmunsell 13y ago
  Pretty much exactly this-- advanced stuff only express-able in Bitmap format (such as photos, complex patterns, blending modes, etc) cannot be represented in SVG. That is, unless you use a Bitmap embedded in the SVG, but then what's the point? It's just simpler to use a bitmap format right now.
- seky 13y ago
  Well, many websites uses simple graphics, simple logos... It's 2013 - yes, and nowadays simple, flat, design is modern, rather than graphics with a lot of effects, that was modern in the past, IMHO. But I agree with your argument regarding to something is not properly - yes, that can be the reason why people don't see the whole thing as reliable
  - jack9 13y ago
    > t's 2013 - yes, and nowadays simple, flat, design is modern, rather than graphics with a lot of effects, that was modern in the past, IMHO. Modern in the past means still in use.
- corresation 13y ago
  no blend mode except "normal" really works reliably across browsers yet Compared to what? What alternative does reliably have blend?
  - ris 13y ago
    There isn't one (except I'm sure someone's going to pop up here and say flash). So the only alternative is something that's been pre-composited down to pixels for you, probably in a png.
qwerty_asdf 13y ago
Because parsing XML can become a bottomless pit of nightmares and sorrow. Unholy floating point calculations that make Baby Jesus cry. Meanwhile, pixel rasters are a finite array of bytes, confined to specific dimensions and resolutions. Plain old integers in 24 bit color with an 8 bit transparency channel. And, specifically with respect to PNG, those pixel values are compressed row-by-row, using the DEFLATE algorithm.
MaxGabriel 13y ago
Re: the author's experience with Android: Android 2.x doesn't support SVG. It makes up 33% of the devices that visit the Google Play store http://caniuse.com/#cats=SVG http://caniuse.com/#cats=SVG http://developer.android.com/about/dashboards/index.html http://developer.android.com/about/dashboards/index.html
- droidist2 13y ago
  True. Android is the new IE when it comes to supporting features like this. Strange since Google pushes HTML 5 so much.
oofabz 13y ago
A vector format is insufficient to make an image look good at all resolutions. Without hinting, lines are not aligned to pixels, making them blurry. We have solved this problem with fonts, but it is extremely complex, both for the artist and for the rendering code.
- terabytest 13y ago
  Not entirely true. A lot of times resolutions are just double the normal one, so the SVG image scales perfectly and looks good.
  - seky 13y ago
    I have written my prev reply before I've seen yours. Yes, if its mostly double-sized resolution then blurring shouldnt be a prob, And when it is some strange "1.something" or "2.something" resolution, then probably also PNGs will look blurred, unles you dont supply exact special PNGs for such resolutions
  - tghw 13y ago
    Assuming it was hinted to the intended resolution. But that's still an extra step.
    - ygra 13y ago
      For 1px lines the only thing you have to remember is to put the points on half-pixels (annoying, but you can just wrap a <g transform='translate(0.5 0.5)> around your drawing if needed. The other thing would be shape-rendering='crispEdges' which also helps, but not everywhere.
    - masklinn 13y ago
      Which you can't have in SVG since the format (IIRC) does not support any hinting. So it's down to luck, and the width of your lines.
      - colanderman 13y ago
bcrescimanno 13y ago
Let's not forget the issue that scaling vectors does not necessarily mean scaling intent and communication. Vector imagery for some things sounds great; in practice, it doesn't always come out as well as you'd hope--and certainly not as well as a hand-optimized set of work. See: http://www.pushing-pixels.org/2011/11/04/about-those-vector-icons.html http://www.pushing-pixels.org/2011/11/04/about-those-vector-...
deletes 13y ago
>>as PNGs are just plain bitmaps<< .png is definitely not a plain bitmap. http://en.wikipedia.org/wiki/Portable_Network_Graphics#Compression http://en.wikipedia.org/wiki/Portable_Network_Graphics#Compr...
etchalon 13y ago
Exporting a bitmap is easy, and will always look correct when rendered. Exporting SVG is difficult, requires specific tools, and is gonna render differently depending on the browser. SVG solved a problem exactly no one had.
- Mindless2112 13y ago
  SVG solved a problem essentially everyone will have: pixel density.
  - masklinn 13y ago
    Except it failed to solve the related problem which everybody already has: eye resolution.
    - avmich 13y ago
      If you know the physical pixel density, SVG image can maintain its physical size on different devices. Now try to do that with PNG... I think PNG and SVG inherently solve somewhat different problems in the realm of image representation, so there are going to be cases where each of them has the clear upper hand. However, with pixel density going up and file sizes and network bandwidth not being the limiting factors in many cases, I'd guess SVG will command increasingly bigger share of uses.
      - etchalon 13y ago
        You'd be dead wrong. SVG has been out for awhile, long before Retina design became a part of the web development workflow, and yet, when faced with the challenge, most web shops didn't swap to an SVG workflow. They just designed everything at twice the resolution. Even Apple, who was leading the way for a hot second there on HDPI and vector assets, has swapped to mostly using 2x image assets. The whole "will we swap to vectors?" debate already happened.
amadeus 13y ago
I'm surprised file size hasn't been mentioned as a mother major reason. With tools like ImageOptim, and ImageAlpha, you can make PNGs INSANELY small with 0 or an imperceptible loss in quality. For example, PNGs do insanely well when you have few numbers of colors that are repeating often. I've had had images that were 640px by 960px (pixel style art) that compressed down to sub 3kb with no quality loss. Good luck getting that with an SVG. (Yes, there are certain types of images that PNGs are a terrible solution for, however, really, what I mean here is, right tool for the job.)
dmlorenzetti 13y ago
I used SVG to make some interactive demos of some methods for solving ordinary differential equations. At the time, I remember being frustrated by the poor documentation available for the scripting aspects. Naturally, there are a number of web resources, but none of them felt authoritative (in the sense of complete coverage). Furthermore, they used different techniques, so it was hard to integrate code samples from different sources. Finally, some had outright errors (my vague memory is that some of this was due to the documentation being written before a working implementation was available). All of this had the effect of making me feel like SVG was a bit of a backwater. I liked the technology, and was willing to use it since I had total control of the machine I was going to run the demo on. However, I didn't feel comfortable with the idea that I could make the demos public and have them run anywhere.
drcode 13y ago
I think SVGs have failed so far on the web because of a sort of "paradox of choice": As soon as you use SVG images, you'll be tempted to make them do things you can't do with PNGs, but you still end up in a world of hurt if you attempt to do this. Chiefly among these new features are (1) inlining directly into html (2) making them interactive via javascript. Both #1 and #2 are possible in theory, but in my experience these features are very painful practice... both of these are still very buggy. That's the problem with SVGs: Most of the new "options" they open up are still not ready for prime time.
- corresation 13y ago
  Most of the new "options" they open up are still not ready for prime time. I had an article in MSDN Magazine promoting SVG graphics 10 friggin' years ago, and it made use of inline SVG and JavaScript animations, to fantastic effect. Since then I've used SVG in countless places, with very little downside. The major problem are some laggard browsers, but if you have a supporting browser neither inlining and script are a problem whatsoever. SVG is one of those technologies where many (such as myself) overestimated the short-term impact, and under-estimated the long term impact. As a technology it was usable and enormously powerful in some situations ten years ago, but it is really just starting to gain serious inertia.
ygra 13y ago
I guess Wikipedia's approach is a fairly good one here: Use SVG behind the scenes and generate PNGs for the articles themselves in the necessary sizes. Fast display of PNGs (also for complex imagery they tend to be smaller, but that's often just because Inkscape's default SVGs are horribly bloated¹) and the vector image for easy changes and printing. That being said, back then I struggled fairly often with annoying bugs in Wikimedia's backend renderer rsvg. It got better over time but back then browser support was also very spotty. By now SVG is still my favorite vector format to use, mainly because it's trivial to write scripts around (it's just XML after all) and converting to PNG if you need it (or whatever else is needed) is trivial.² So generally I'd say SVG is very much not dead, it's just rarely used directly on the web, except for interactive things where hit-testing arbitrary shapes is important. ____ ¹ I used to vectorize a few (around 200–300, I think) flags on Wikimedia Commons and for simple shapes I concentrated on it was usually a difference of 350 bytes vs. 2–3 KiB. I wrote my code by hand for the most part, utilizing a few templates for common flag formats (n horizontal or vertical stripes, checkerboard, etc.) and small scripts for the more annoying things to write by hand, like wavy lines. ² Current use case from today: action bar icons on Android. When creating them in Eclipse from an image it only generates enabled, not disabled icons and I have to remember what padding I used and select the correct theme. After two or three changes in the source images (which were SVG anyway) it was enough and I just wrote a tiny script to generate them. Another use case were the images in my final thesis which I kept in SVG because back then I wasn't sure yet whether to use Word (needs EMF) or LaTeX (needs PDF) for writing. The fact that I needed Graphviz a lot which outputs nice, clean SVG also helped.
marijn 13y ago
The responses here (so far) are mostly pointing out why SVG is not suitable for all situations. There are many images where - SVG will be smaller than a bitmap - The sub-pixel rendering isn't really an issue (do you check that all the lines are aligned on pixels when you export something from illustrator?) - No advanced/poorly supported features are necessary Platform support is still a stumbling block, but that will get better. I seriously considered going svg-only for the vector-friendly illustrations in the new edition of http://eloquentjavascript.net http://eloquentjavascript.net . But in order to not screw over people on old devices, I will probably use svg with png fallbacks instead.
- guptaneil 13y ago
  Honest question: Will people with devices old enough to not be able to render svg really be reading a programming book?
  - marijn 13y ago
    Well, my own phone is unable to render svg, so I can imagine there is such an audience.
  - hack37 13y ago
    Being a programmer doesn't mean living with the latest gadget.
crazygringo 13y ago
> For some time, all major browsers already support SVG. Not time enough. Plenty of people still use IE8, which doesn't.
- frik 13y ago
  You can use SVGWeb as fallback solution for IE6-8 user: http://code.google.com/p/svgweb/ http://code.google.com/p/svgweb/
  - panzi 13y ago
    If your SVG file is properly crafted (viewBox & maybe preserveAspectRatio attributes) then you can do this: <object type="image/svg+xml" width="640" height="480" data="http://example.com/image.svg"> <img src="http://example.com/image.png"/> </object>
puller 13y ago
Because browser support is inconsistent, SVGs are often larger than equivalent than even lightly optimized PNGs, and it's a lot easier to find or create raster images than to obtain high-quality vector art. Also, you actually often want different images at different scales, so that automatically scaling one image is not that big an advantage. I want to use SVG, particularly in Javascript apps. It seems like a more elegant solution/workflow for things like icons. It would certainly beat abusing fonts to put small images on a page. but it has sort of missed its opportunity.
sambeau 13y ago
I use SVG a lot and I'd say the reasons are: * Browser support is still new and in places still a little rough * IE support has only recently arrived * SVG creation tools are either rough or expensive * SVG can create sub-Flash-like performance if used carelessly * SVG has no detail optimisation (or detail hinting) I think we're about to see SVG usage pick-up steam now that IE has support and retina displays are becoming commonplace. Hopefully we'll get the tools and performance we deserve. I'm very hopeful for SVG in the next 18 months.
- gglanzani 13y ago
  [Not trolling, genuinely interested in the answer] > * SVG can creat sub-Flash-like performance if used carelessly Could you elaborate on that? What should I be aware of if exporting vector art from, say, Illustrator or Inkscape?
  - ygra 13y ago
    From Inkscape? Little, as SVG is its native format and thus Inkscape's feature set aligns nicely with the capabilities of the format (if used carefully, e.g. using clones instead of copies for identical shapes, etc.). Illustrator, however, will export more or less with a minimum SVG feature set used and for complex drawings that may end up fairly large and fairly inefficient. Drop shadows and filters in general are a concern. Not so much on desktop browsers nowadays, but in mobile very much.
  - sambeau 13y ago
    iOS performance is generally awful with SVG. Scrolling used to be bad but I think Webkit fixed that bug. Too much detail has been the cause of the worst performance (and crashing) I've seen — one image of a playing card froze my iPad. http://code.google.com/p/vectorized-playing-cards/ http://code.google.com/p/vectorized-playing-cards/ try this guy: http://www.totalnonsense.com/misc_images/Jack_of_Spades_vector.svg http://www.totalnonsense.com/misc_images/Jack_of_Spades_vect... Blurs can be slow on large images. Drawing Big SVGs can be problematic too.
  - Grue3 13y ago
taf2 13y ago
We use SVG on our homepage via raphaeljs to draw the graphics showing marketing, phone calls, metrics, and insights... It was always my goal to one day animate it to help better explain our product, but for now I think it looks pretty good and the PNG version was larger in bytes when converted... the example is here: https://calltrackingmetrics.com/features https://calltrackingmetrics.com/features
anjc 13y ago
Because they're completely different formats to be used for completely different purposes?
neovive 13y ago
The SVG spec has been around for so long, but the fact that it competed directly with SWF held it back. Adobe was a major proponent of SVG until they bought Flash and focused their efforts accordingly. Although SVG is "readable" in a text editor, all but the simplest shapes are extremely complex and require the use of graphics editors such as Inkscape. Vector formats are definitely the future for source images as they can generate any size bitmap you need for any device. However, as a delivery format, SVG will likely be relegated to niche and specialized sites (e.g. data visualizations and animations) for quite a while.
ScotterC 13y ago
I would say the main reason is because there's not a 'Save As SVG' in photoshop. Most non tech people haven't heard of SVG and by the time they have, they already have a process for making images and the switch doesn't have enough apparent value on the surface.
- Pxtl 13y ago
  Also, illustrator sucks.
  - nness 13y ago
    Illustrator is an absolutely fantastic tool for print production and design. It is not a suitable tool for SVG, hasn't been for many versions (if it ever was).
    - Pxtl 13y ago
      Adobe's forgotten, unpromoted, and now discontinued fireworks is their actual svg art tool. Apparently illustrator isn't meant to illustrate.
eddieh 13y ago
Because IE 8 doesn't support SVGs and still accounts for >20% of desktop traffic (by some reports). Likewise, Android 2.x doesn't support SVGs and accounts for some non-ignorable amount of mobile traffic. Where I currently work we can't support SVGs with some projects due to a bug in the middleware we're mandated to use.
jahewson 13y ago
Nobody has mentioned the abandonment of SVG 1.2 as a factor. It was dropped by the W3C and never implemented in any browsers. This not only stalled improvements to SVG 1.1 but created a situation where the editing software (e.g. Inkscape) allows the user to create files using SVG 1.2 features which are invalid in SVG 1.1. The abandonment has resulted in much-needed improvements to SVG being delayed. The last full release of SVG was 1.1 which was in 2003, we won't see another full release until SVG 2 which is expected in 2014, over a decade later! Never mind the fact the browser implementations of SVG are still riddled with bugs and none are complete.
- ahoge 13y ago
  > we won't see another full release until SVG 2 which is expected in 2014, over a decade later! HTML4: 1998 HTML5: 2014
  - pfraze 13y ago
    Doesnt really compare
  - nerfhammer 13y ago
    HTML5 has been rolling out since 2004
    - ahoge 13y ago
      It's from recommendation to recommendation.
  - Tloewald 13y ago
    The big difference is HTML was in widespread use already in 1998. Delaying the next version update when your standard isn't very popular is not a recipe for success.
  - leokun 13y ago
    More like: HTML4: 1998 XHTML: 2000 HTML5: 2014 Also, I blame IE 6.
egypturnash 13y ago
"Why have SVG images not yet replaced PNG on the web?" I'm an artist who's been using Adobe Illustrator as her primary medium for thirteen years. Here's some reasons why my site is still serving up tons of bitmap images: - Any interesting vector image will be a much larger file as an svg than a web-res png/gif/jpg. - Sophisticated effects in AI can get lost in the transition to SVG. I don't know if this is AI's fault, SVG's lack of support, or the fault of the various things rendering the SVG, and the first point leaves me disinterested in experimenting. That said, I have been playing with using web fonts for sets of simple images. Also, most of my artist friends are completely baffled by AI; they prefer bitmap programs like Photoshop, Sai, or Artrage.
tmarthal 13y ago
I think that the web is slowly starting to adopt SVGs where it makes sense. d3.js is bringing svg charting to the web in a major way. Most, if not all, modern web dashboards are using it. Google Maps has been using SVG icons for custom markers for awhile, embedded into their json configuration. This may not be strictly 'the web', but it is a major component of online GIS applications.
nyar 13y ago
Easy answer - when you're making an image in photoshop and you go to save it you don't get to save it as .svg
JoelSutherland 13y ago
IE8 doesn't support SVG and still has nearly 15% marketshare in the US. This is essentially the entire reason.
olegp 13y ago
Because most of the images out there are in pixel and not vector format. Converting the latter to the former automatically doesn't always produce the desired results. At https://starthq.com https://starthq.com we do use SVG for the logo and all icons. Falling back to PNG for older browsers requires a CSS hack though and that fails on some older mobile devices.
JohnHaugeland 13y ago
1) Different browsers can render SVG pretty differently, especially where two regions are within a pixel of one another. If you have a blue rect next to a red rect with a yellow background, some browsers will render the middle line purple, some green, some orange, and some brown. 2) Pixel choices by vector renderers are generally dramatically worse than a human artist's choices. We don't want accuracy, we want perceptual emphasis. Look at NES Mario in your head, then look at the blur you'd get if you took a modern hi-res Mario and vector rendered it at that size. For icons, this can be murder. 3) IE <= 8 is still a pretty significant chunk of your viewers. 4) There's a lot of knowledge built up around how to work with pixel images, especially when sprite sheeting for performance. Much of that knowledge needs to be re-learned for vector. Even when it's a good idea, many developers feel they don't have the time for a knowledge overhaul. 5) A big chunk of the web is legacy sites. This is why you still see javascript in html comments, or the occasional isindex. They aren't getting updated, pretty much ever. 6) For visually complex sites, SVG can still drag on budget and older mobile devices. 7) Older android had SVG turned off in Chrome. 8) It's a lot harder to get vector artists than pixel artists; it's a lot harder for artists to give developers SVG than pixel images. 9) Because it isn't trendy yet.
aidenn0 13y ago
SVGs are more expensive to decode: The law of spline demand.
grogenaut 13y ago
It's pretty simple. People in charge of corporate logos want COMPLETE CONTROL over how they look. If a rendering engine can mess it up, they're not going to use it. Thus PNGs. What you put into a PNG is what you get out. Not so with SVG.
brianfryer 13y ago
If you're going to use SVGs, might as well make a font out of it. Otherwise, PNG is the way to go to guarantee uniform display.
- illicium 13y ago
  Icon fonts are a horrible hack that's only in use because SVG support in browsers has frankly been terrible so far. Plus, you can only use them for single-color shapes.
drill_sarge 13y ago
you could ask the same question for .gif, flash video, mp3, mpeg2, analog tv/radio, pci bus, d-sub...
zach_s 13y ago
Because people haven't caught on yet. Browsers will start to support it and it will catch on once people realize its vast benefits over PNG. For now, it's not worth it for people to switch.
ronreiter 13y ago
Because you need both raster and vector images. You can't just ignore all pixel based images.
Grue3 13y ago
Because they are completely different image formats for completely different purposes! I'm so tired of these articles. PNG vs JPG, Animated GIF vs video, Flash vs HTML5. These things have barely anything in common!

76 points by seky 13y ago

ris 13y ago

Answer: because there are plenty of things you simply can't express in SVG with its current level of support across browsers. e.g. no blend mode except "normal" really works reliably across browsers yet. And just a reminder: it's 2013, everyone. Next question...

andrewmunsell 13y ago
Pretty much exactly this-- advanced stuff only express-able in Bitmap format (such as photos, complex patterns, blending modes, etc) cannot be represented in SVG. That is, unless you use a Bitmap embedded in the SVG, but then what's the point? It's just simpler to use a bitmap format right now.
seky 13y ago
Well, many websites uses simple graphics, simple logos... It's 2013 - yes, and nowadays simple, flat, design is modern, rather than graphics with a lot of effects, that was modern in the past, IMHO. But I agree with your argument regarding to something is not properly - yes, that can be the reason why people don't see the whole thing as reliable
- jack9 13y ago
  > t's 2013 - yes, and nowadays simple, flat, design is modern, rather than graphics with a lot of effects, that was modern in the past, IMHO. Modern in the past means still in use.
corresation 13y ago
no blend mode except "normal" really works reliably across browsers yet Compared to what? What alternative does reliably have blend?
- ris 13y ago
  There isn't one (except I'm sure someone's going to pop up here and say flash). So the only alternative is something that's been pre-composited down to pixels for you, probably in a png.

qwerty_asdf 13y ago

Because parsing XML can become a bottomless pit of nightmares and sorrow. Unholy floating point calculations that make Baby Jesus cry. Meanwhile, pixel rasters are a finite array of bytes, confined to specific dimensions and resolutions. Plain old integers in 24 bit color with an 8 bit transparency channel. And, specifically with respect to PNG, those pixel values are compressed row-by-row, using the DEFLATE algorithm.

MaxGabriel 13y ago

Re: the author's experience with Android: Android 2.x doesn't support SVG. It makes up 33% of the devices that visit the Google Play store http://caniuse.com/#cats=SVG http://caniuse.com/#cats=SVG http://developer.android.com/about/dashboards/index.html http://developer.android.com/about/dashboards/index.html

droidist2 13y ago
True. Android is the new IE when it comes to supporting features like this. Strange since Google pushes HTML 5 so much.

oofabz 13y ago

A vector format is insufficient to make an image look good at all resolutions. Without hinting, lines are not aligned to pixels, making them blurry. We have solved this problem with fonts, but it is extremely complex, both for the artist and for the rendering code.

terabytest 13y ago
Not entirely true. A lot of times resolutions are just double the normal one, so the SVG image scales perfectly and looks good.
- seky 13y ago
  I have written my prev reply before I've seen yours. Yes, if its mostly double-sized resolution then blurring shouldnt be a prob, And when it is some strange "1.something" or "2.something" resolution, then probably also PNGs will look blurred, unles you dont supply exact special PNGs for such resolutions
- tghw 13y ago
  Assuming it was hinted to the intended resolution. But that's still an extra step.
  - ygra 13y ago
    For 1px lines the only thing you have to remember is to put the points on half-pixels (annoying, but you can just wrap a <g transform='translate(0.5 0.5)> around your drawing if needed. The other thing would be shape-rendering='crispEdges' which also helps, but not everywhere.
  - masklinn 13y ago
    Which you can't have in SVG since the format (IIRC) does not support any hinting. So it's down to luck, and the width of your lines.
    - colanderman 13y ago

bcrescimanno 13y ago

Let's not forget the issue that scaling vectors does not necessarily mean scaling intent and communication. Vector imagery for some things sounds great; in practice, it doesn't always come out as well as you'd hope--and certainly not as well as a hand-optimized set of work. See: http://www.pushing-pixels.org/2011/11/04/about-those-vector-icons.html http://www.pushing-pixels.org/2011/11/04/about-those-vector-...

deletes 13y ago

>>as PNGs are just plain bitmaps<< .png is definitely not a plain bitmap. http://en.wikipedia.org/wiki/Portable_Network_Graphics#Compression http://en.wikipedia.org/wiki/Portable_Network_Graphics#Compr...

etchalon 13y ago

Exporting a bitmap is easy, and will always look correct when rendered. Exporting SVG is difficult, requires specific tools, and is gonna render differently depending on the browser. SVG solved a problem exactly no one had.

Mindless2112 13y ago
SVG solved a problem essentially everyone will have: pixel density.
- masklinn 13y ago
  Except it failed to solve the related problem which everybody already has: eye resolution.
  - avmich 13y ago
    If you know the physical pixel density, SVG image can maintain its physical size on different devices. Now try to do that with PNG... I think PNG and SVG inherently solve somewhat different problems in the realm of image representation, so there are going to be cases where each of them has the clear upper hand. However, with pixel density going up and file sizes and network bandwidth not being the limiting factors in many cases, I'd guess SVG will command increasingly bigger share of uses.
    - etchalon 13y ago
      You'd be dead wrong. SVG has been out for awhile, long before Retina design became a part of the web development workflow, and yet, when faced with the challenge, most web shops didn't swap to an SVG workflow. They just designed everything at twice the resolution. Even Apple, who was leading the way for a hot second there on HDPI and vector assets, has swapped to mostly using 2x image assets. The whole "will we swap to vectors?" debate already happened.

amadeus 13y ago

I'm surprised file size hasn't been mentioned as a mother major reason. With tools like ImageOptim, and ImageAlpha, you can make PNGs INSANELY small with 0 or an imperceptible loss in quality. For example, PNGs do insanely well when you have few numbers of colors that are repeating often. I've had had images that were 640px by 960px (pixel style art) that compressed down to sub 3kb with no quality loss. Good luck getting that with an SVG. (Yes, there are certain types of images that PNGs are a terrible solution for, however, really, what I mean here is, right tool for the job.)

dmlorenzetti 13y ago

I used SVG to make some interactive demos of some methods for solving ordinary differential equations. At the time, I remember being frustrated by the poor documentation available for the scripting aspects. Naturally, there are a number of web resources, but none of them felt authoritative (in the sense of complete coverage). Furthermore, they used different techniques, so it was hard to integrate code samples from different sources. Finally, some had outright errors (my vague memory is that some of this was due to the documentation being written before a working implementation was available). All of this had the effect of making me feel like SVG was a bit of a backwater. I liked the technology, and was willing to use it since I had total control of the machine I was going to run the demo on. However, I didn't feel comfortable with the idea that I could make the demos public and have them run anywhere.

drcode 13y ago

I think SVGs have failed so far on the web because of a sort of "paradox of choice": As soon as you use SVG images, you'll be tempted to make them do things you can't do with PNGs, but you still end up in a world of hurt if you attempt to do this. Chiefly among these new features are (1) inlining directly into html (2) making them interactive via javascript. Both #1 and #2 are possible in theory, but in my experience these features are very painful practice... both of these are still very buggy. That's the problem with SVGs: Most of the new "options" they open up are still not ready for prime time.

corresation 13y ago
Most of the new "options" they open up are still not ready for prime time. I had an article in MSDN Magazine promoting SVG graphics 10 friggin' years ago, and it made use of inline SVG and JavaScript animations, to fantastic effect. Since then I've used SVG in countless places, with very little downside. The major problem are some laggard browsers, but if you have a supporting browser neither inlining and script are a problem whatsoever. SVG is one of those technologies where many (such as myself) overestimated the short-term impact, and under-estimated the long term impact. As a technology it was usable and enormously powerful in some situations ten years ago, but it is really just starting to gain serious inertia.

ygra 13y ago

I guess Wikipedia's approach is a fairly good one here: Use SVG behind the scenes and generate PNGs for the articles themselves in the necessary sizes. Fast display of PNGs (also for complex imagery they tend to be smaller, but that's often just because Inkscape's default SVGs are horribly bloated¹) and the vector image for easy changes and printing. That being said, back then I struggled fairly often with annoying bugs in Wikimedia's backend renderer rsvg. It got better over time but back then browser support was also very spotty. By now SVG is still my favorite vector format to use, mainly because it's trivial to write scripts around (it's just XML after all) and converting to PNG if you need it (or whatever else is needed) is trivial.² So generally I'd say SVG is very much not dead, it's just rarely used directly on the web, except for interactive things where hit-testing arbitrary shapes is important. ____ ¹ I used to vectorize a few (around 200–300, I think) flags on Wikimedia Commons and for simple shapes I concentrated on it was usually a difference of 350 bytes vs. 2–3 KiB. I wrote my code by hand for the most part, utilizing a few templates for common flag formats (n horizontal or vertical stripes, checkerboard, etc.) and small scripts for the more annoying things to write by hand, like wavy lines. ² Current use case from today: action bar icons on Android. When creating them in Eclipse from an image it only generates enabled, not disabled icons and I have to remember what padding I used and select the correct theme. After two or three changes in the source images (which were SVG anyway) it was enough and I just wrote a tiny script to generate them. Another use case were the images in my final thesis which I kept in SVG because back then I wasn't sure yet whether to use Word (needs EMF) or LaTeX (needs PDF) for writing. The fact that I needed Graphviz a lot which outputs nice, clean SVG also helped.

marijn 13y ago

The responses here (so far) are mostly pointing out why SVG is not suitable for all situations. There are many images where - SVG will be smaller than a bitmap - The sub-pixel rendering isn't really an issue (do you check that all the lines are aligned on pixels when you export something from illustrator?) - No advanced/poorly supported features are necessary Platform support is still a stumbling block, but that will get better. I seriously considered going svg-only for the vector-friendly illustrations in the new edition of http://eloquentjavascript.net http://eloquentjavascript.net . But in order to not screw over people on old devices, I will probably use svg with png fallbacks instead.

guptaneil 13y ago
Honest question: Will people with devices old enough to not be able to render svg really be reading a programming book?
- marijn 13y ago
  Well, my own phone is unable to render svg, so I can imagine there is such an audience.
- hack37 13y ago
  Being a programmer doesn't mean living with the latest gadget.

crazygringo 13y ago

> For some time, all major browsers already support SVG. Not time enough. Plenty of people still use IE8, which doesn't.

frik 13y ago
You can use SVGWeb as fallback solution for IE6-8 user: http://code.google.com/p/svgweb/ http://code.google.com/p/svgweb/
- panzi 13y ago
  If your SVG file is properly crafted (viewBox & maybe preserveAspectRatio attributes) then you can do this: <object type="image/svg+xml" width="640" height="480" data="http://example.com/image.svg"> <img src="http://example.com/image.png"/> </object>

puller 13y ago

Because browser support is inconsistent, SVGs are often larger than equivalent than even lightly optimized PNGs, and it's a lot easier to find or create raster images than to obtain high-quality vector art. Also, you actually often want different images at different scales, so that automatically scaling one image is not that big an advantage. I want to use SVG, particularly in Javascript apps. It seems like a more elegant solution/workflow for things like icons. It would certainly beat abusing fonts to put small images on a page. but it has sort of missed its opportunity.

sambeau 13y ago

I use SVG a lot and I'd say the reasons are: * Browser support is still new and in places still a little rough * IE support has only recently arrived * SVG creation tools are either rough or expensive * SVG can create sub-Flash-like performance if used carelessly * SVG has no detail optimisation (or detail hinting) I think we're about to see SVG usage pick-up steam now that IE has support and retina displays are becoming commonplace. Hopefully we'll get the tools and performance we deserve. I'm very hopeful for SVG in the next 18 months.

gglanzani 13y ago
[Not trolling, genuinely interested in the answer] > * SVG can creat sub-Flash-like performance if used carelessly Could you elaborate on that? What should I be aware of if exporting vector art from, say, Illustrator or Inkscape?
- ygra 13y ago
  From Inkscape? Little, as SVG is its native format and thus Inkscape's feature set aligns nicely with the capabilities of the format (if used carefully, e.g. using clones instead of copies for identical shapes, etc.). Illustrator, however, will export more or less with a minimum SVG feature set used and for complex drawings that may end up fairly large and fairly inefficient. Drop shadows and filters in general are a concern. Not so much on desktop browsers nowadays, but in mobile very much.
- sambeau 13y ago
  iOS performance is generally awful with SVG. Scrolling used to be bad but I think Webkit fixed that bug. Too much detail has been the cause of the worst performance (and crashing) I've seen — one image of a playing card froze my iPad. http://code.google.com/p/vectorized-playing-cards/ http://code.google.com/p/vectorized-playing-cards/ try this guy: http://www.totalnonsense.com/misc_images/Jack_of_Spades_vector.svg http://www.totalnonsense.com/misc_images/Jack_of_Spades_vect... Blurs can be slow on large images. Drawing Big SVGs can be problematic too.
- Grue3 13y ago

taf2 13y ago

We use SVG on our homepage via raphaeljs to draw the graphics showing marketing, phone calls, metrics, and insights... It was always my goal to one day animate it to help better explain our product, but for now I think it looks pretty good and the PNG version was larger in bytes when converted... the example is here: https://calltrackingmetrics.com/features https://calltrackingmetrics.com/features

anjc 13y ago

Because they're completely different formats to be used for completely different purposes?

neovive 13y ago

The SVG spec has been around for so long, but the fact that it competed directly with SWF held it back. Adobe was a major proponent of SVG until they bought Flash and focused their efforts accordingly. Although SVG is "readable" in a text editor, all but the simplest shapes are extremely complex and require the use of graphics editors such as Inkscape. Vector formats are definitely the future for source images as they can generate any size bitmap you need for any device. However, as a delivery format, SVG will likely be relegated to niche and specialized sites (e.g. data visualizations and animations) for quite a while.

ScotterC 13y ago

I would say the main reason is because there's not a 'Save As SVG' in photoshop. Most non tech people haven't heard of SVG and by the time they have, they already have a process for making images and the switch doesn't have enough apparent value on the surface.

Pxtl 13y ago
Also, illustrator sucks.
- nness 13y ago
  Illustrator is an absolutely fantastic tool for print production and design. It is not a suitable tool for SVG, hasn't been for many versions (if it ever was).
  - Pxtl 13y ago
    Adobe's forgotten, unpromoted, and now discontinued fireworks is their actual svg art tool. Apparently illustrator isn't meant to illustrate.

eddieh 13y ago

Because IE 8 doesn't support SVGs and still accounts for >20% of desktop traffic (by some reports). Likewise, Android 2.x doesn't support SVGs and accounts for some non-ignorable amount of mobile traffic. Where I currently work we can't support SVGs with some projects due to a bug in the middleware we're mandated to use.

jahewson 13y ago

Nobody has mentioned the abandonment of SVG 1.2 as a factor. It was dropped by the W3C and never implemented in any browsers. This not only stalled improvements to SVG 1.1 but created a situation where the editing software (e.g. Inkscape) allows the user to create files using SVG 1.2 features which are invalid in SVG 1.1. The abandonment has resulted in much-needed improvements to SVG being delayed. The last full release of SVG was 1.1 which was in 2003, we won't see another full release until SVG 2 which is expected in 2014, over a decade later! Never mind the fact the browser implementations of SVG are still riddled with bugs and none are complete.

ahoge 13y ago
> we won't see another full release until SVG 2 which is expected in 2014, over a decade later! HTML4: 1998 HTML5: 2014
- pfraze 13y ago
  Doesnt really compare
- nerfhammer 13y ago
  HTML5 has been rolling out since 2004
  - ahoge 13y ago
    It's from recommendation to recommendation.
- Tloewald 13y ago
  The big difference is HTML was in widespread use already in 1998. Delaying the next version update when your standard isn't very popular is not a recipe for success.
- leokun 13y ago
  More like: HTML4: 1998 XHTML: 2000 HTML5: 2014 Also, I blame IE 6.

egypturnash 13y ago

"Why have SVG images not yet replaced PNG on the web?" I'm an artist who's been using Adobe Illustrator as her primary medium for thirteen years. Here's some reasons why my site is still serving up tons of bitmap images: - Any interesting vector image will be a much larger file as an svg than a web-res png/gif/jpg. - Sophisticated effects in AI can get lost in the transition to SVG. I don't know if this is AI's fault, SVG's lack of support, or the fault of the various things rendering the SVG, and the first point leaves me disinterested in experimenting. That said, I have been playing with using web fonts for sets of simple images. Also, most of my artist friends are completely baffled by AI; they prefer bitmap programs like Photoshop, Sai, or Artrage.

tmarthal 13y ago

I think that the web is slowly starting to adopt SVGs where it makes sense. d3.js is bringing svg charting to the web in a major way. Most, if not all, modern web dashboards are using it. Google Maps has been using SVG icons for custom markers for awhile, embedded into their json configuration. This may not be strictly 'the web', but it is a major component of online GIS applications.

nyar 13y ago

Easy answer - when you're making an image in photoshop and you go to save it you don't get to save it as .svg

JoelSutherland 13y ago

IE8 doesn't support SVG and still has nearly 15% marketshare in the US. This is essentially the entire reason.

olegp 13y ago

Because most of the images out there are in pixel and not vector format. Converting the latter to the former automatically doesn't always produce the desired results. At https://starthq.com https://starthq.com we do use SVG for the logo and all icons. Falling back to PNG for older browsers requires a CSS hack though and that fails on some older mobile devices.

JohnHaugeland 13y ago

1) Different browsers can render SVG pretty differently, especially where two regions are within a pixel of one another. If you have a blue rect next to a red rect with a yellow background, some browsers will render the middle line purple, some green, some orange, and some brown. 2) Pixel choices by vector renderers are generally dramatically worse than a human artist's choices. We don't want accuracy, we want perceptual emphasis. Look at NES Mario in your head, then look at the blur you'd get if you took a modern hi-res Mario and vector rendered it at that size. For icons, this can be murder. 3) IE <= 8 is still a pretty significant chunk of your viewers. 4) There's a lot of knowledge built up around how to work with pixel images, especially when sprite sheeting for performance. Much of that knowledge needs to be re-learned for vector. Even when it's a good idea, many developers feel they don't have the time for a knowledge overhaul. 5) A big chunk of the web is legacy sites. This is why you still see javascript in html comments, or the occasional isindex. They aren't getting updated, pretty much ever. 6) For visually complex sites, SVG can still drag on budget and older mobile devices. 7) Older android had SVG turned off in Chrome. 8) It's a lot harder to get vector artists than pixel artists; it's a lot harder for artists to give developers SVG than pixel images. 9) Because it isn't trendy yet.

aidenn0 13y ago

SVGs are more expensive to decode: The law of spline demand.

grogenaut 13y ago

It's pretty simple. People in charge of corporate logos want COMPLETE CONTROL over how they look. If a rendering engine can mess it up, they're not going to use it. Thus PNGs. What you put into a PNG is what you get out. Not so with SVG.

brianfryer 13y ago

If you're going to use SVGs, might as well make a font out of it. Otherwise, PNG is the way to go to guarantee uniform display.

illicium 13y ago
Icon fonts are a horrible hack that's only in use because SVG support in browsers has frankly been terrible so far. Plus, you can only use them for single-color shapes.

drill_sarge 13y ago

you could ask the same question for .gif, flash video, mp3, mpeg2, analog tv/radio, pci bus, d-sub...

zach_s 13y ago

Because people haven't caught on yet. Browsers will start to support it and it will catch on once people realize its vast benefits over PNG. For now, it's not worth it for people to switch.

ronreiter 13y ago

Because you need both raster and vector images. You can't just ignore all pixel based images.

Grue3 13y ago

Because they are completely different image formats for completely different purposes! I'm so tired of these articles. PNG vs JPG, Animated GIF vs video, Flash vs HTML5. These things have barely anything in common!