Non-visible Flash content blocked in September; Flash fully deprecated by December.
Last year, Chrome made Flash ads click-to-play; now, Google is trying to kill off Flash completely.

Starting with Chrome 53, due out early next month, the browser will automatically block tiny and non-visible Flash content, such as tracking and fingerprint cookies that are notoriously hard to shake off. Then, with Chrome 55 in December, Flash will be deprecated entirely, with exceptions for "sites which only support Flash." In both cases HTML5 is expected to take up the reins.

The changes in Chrome 53 are mostly targeted at behind-the-scenes Flash widgets that many sites use for tracking and analytics purposes. Best-case these non-visible elements can slow down your browsing experience, worst-case they might cause stability issues or reduce battery life on mobile devices. Google says that publishers are in the process of moving these widgets over to HTML5.

Chrome 53's behaviour towards Flash almost exactly mirrors that of Firefox 48, which was released last week.

Chrome 55, however, will go one step further. HTML5 will be made the "default experience," except when the site only supports Flash. When you do visit such a site, Chrome will ask you if you want to enable Flash.

When Google originally discussed the HTML5-by-default feature back in May there was going to be a "temporary whitelist" containing the top 10 Flash-using sites, "to reduce initial user impact and avoid over-prompting." That list included YouTube, Facebook, Twitch, Yahoo, and VK, amongst others. It isn't clear if that whitelist will still be used in Chrome 55, or if all sites will be treated the same way.

Meanwhile, with the Windows 10 Anniversary Update, Microsoft's Edge browser recently introduced click-to-play for non-essential Flash content, including non-visible elements and ads.

Flash is not long for this world.