GA's "Filter bots" setting simply applies the IAB bot filtering list[1]. The resources required to operate a page rendering bot[2] used to be a high enough bar

GA's "Filter bots" setting simply applies the IAB bot filtering list[1]. The resources required to operate a page rendering bot[2] used to be a high enough bar that the ones doing so were large actors and would make their way onto that list pretty quickly. The IAB list is still a helpful baseline (if overpriced if you want to lease the list itself[3]), but all it's doing is applying suppression based on things like known bot IP ranges and user agents. It's far less effective than it used to be since it's so incredibly easy and cheap nowadays for anyone with an interest to spin up a rendering bot. Now you've got to supplement it actively with your own set of filters and heuristics if you really want to get rid of bot traffic polluting your data. [1] https://iabtechlab.com/software/iababc-international-spiders-and-bots-list/ https://iabtechlab.com/software/iababc-international-spiders... [2] Scraping bots were cheap and easy to run before, but didn't render the GA javascript code so never showed up in analytics. It's only bots that use something like a headless browser to render the page that show up in GA, and those have only become commoditized and cheap/easy relatively recently. [3] Google applies the IAB list to your traffic for free if you check the setting for it, but if you want to use the IAB list yourself you have to pay $4k - $14k annually to lease it from IAB.