The polyfills (there is another by Facebook in addition to the one you linked) are slow and buggy (look at all the open issues, or try using it in a non-trivial

The polyfills (there is another by Facebook in addition to the one you linked) are slow and buggy (look at all the open issues, or try using it in a non-trivial project yourself). Web SQL in Safari is also slow (check any performance benchmark) and buggy (see the huge bugs introduced in the most recent version of Safari). So the truth is probably closer to "crippling" than just "annoying". Who is going to go through the trouble of working around all the polyfill and browser bugs, only to be rewarded with horrible performance? Not many people except those with simple needs. Making something complex? Better put it in the App Store. Libraries like localForage are great if you're doing very simple stuff. But if you need to use slightly more advanced DB features (indexes, transactions, etc), they don't work. IndexedDB, while not a panacea, does generally work for that stuff... except for Safari :)