How Flash is emulated

Many of the old Flash game websites seem to largely still work and have playable games. How are they doing this?

Short version: they’re mostly not running the old Adobe plug-in at all. They’re using emulators and repackaged runtimes that run Flash content without the original Flash Player.

Here are the main tricks you’re seeing:

• Ruffle (Rust → WebAssembly emulator). Lots of sites (and the Internet Archive) drop in a small JS snippet that loads Ruffle. It emulates Flash in the page via WebAssembly, so nothing needs to be installed and it’s far safer than the old plug-in. It already plays most ActionScript 1/2 content well, with growing ActionScript 3 support. (ruffle.rs)

• “Virtualized” Flash Player (CheerpX for Flash). Some sites—especially ones with more complex AS3 apps—embed CheerpX, which runs an x86 build of Flash Player inside a WebAssembly VM in the browser. This keeps unmodified SWFs working, including enterprise-style apps. (Leaning Technologies Developer Hub)

• Other web emulators / engines. Projects like AwayFL (TypeScript) are used by a few portals to bring specific games back, including some mobile support. There are also one-off SWF→HTML5 conversions for certain titles. (AwayFL)

• Local launchers (preservation packs). If you’re using something like BlueMaxima’s Flashpoint, it bundles preserved games with a local launcher and custom browser/tech to bypass site-locks, so you can play a huge offline library. (WIRED)

• Licensed enterprise variants. After Adobe ended Flash on the web (Dec 31, 2020 EOL; “kill switch” Jan 12, 2021), Adobe partnered with HARMAN to provide paid, supported enterprise builds of Flash Player / AIR for organizations that still need them. Some sites/apps rely on that route. (Adobe)

Why this was needed: Adobe and browsers blocked the classic plug-in in 2021 for safety; the emulation/virtualization approaches bring content back without reinstating the insecure plug-in. (Adobe)

Practical upshot when you visit these sites:

• Older games (AS1/AS2) usually “just work” via Ruffle.
• Heavier AS3 titles may need CheerpX/AwayFL or a local launcher like Flashpoint, so compatibility varies from site to site.
• Security is better than the old days because everything runs sandboxed in WebAssembly rather than a system-level plug-in. (ruffle.rs)

If you want, tell me a couple of the sites/games you’re visiting and I can point out which approach they’re using and the best way to play them today.