Firefox 84 Ships as the Last Browser to Say Goodbye to Flash

Mozilla pushed Firefox 84 out the door on December 15, and buried in the release notes is a line that feels bigger than it looks: this is the last version of Firefox that will support Adobe Flash. Not because Mozilla ripped it out early — Flash Player itself goes end-of-life industry-wide at the end of this month, and every major browser vendor has been synchronizing their exit for years. Firefox 84 is just the version that happens to be sitting in the release channel when the plug finally gets pulled.

If you’ve been putting off dealing with that one internal dashboard or ancient Flash-based tool at work, this is your actual deadline. Come January, there’s no version of Firefox, Chrome, or Edge that will run it for you.

The more immediately useful news in 84 is native Apple Silicon support. Firefox now ships a build compiled for M1 Macs instead of running under Rosetta 2 emulation, and Mozilla is citing launch times over 2.5x faster as a result. That’s a meaningful number given how much noise there’s been this month about M1 MacBooks outperforming their Intel predecessors — it’s good to see browser vendors moving quickly rather than leaving Mac users stuck on emulated builds for months. Chrome still hasn’t shipped a native Apple Silicon build as of this week, so Firefox getting there first is a nice bit of momentum for Mozilla, even if its market share numbers haven’t budged much in years.

WebRender keeps spreading

Firefox 84 also widens the rollout of WebRender, Mozilla’s GPU-accelerated rendering engine written in Rust. WebRender has been rolling out gradually since 2019, and each release quietly adds it to more hardware configurations — this time expanding coverage on Windows. The pitch is smoother scrolling and animation by pushing more rendering work onto the GPU instead of the CPU, and in my experience the difference is real on lower-end laptops where Firefox used to feel a little sluggish on pages heavy with CSS animations.

None of this is flashy (last Flash pun, I promise) compared to the AI and space stories dominating tech news this week, but browser engines are the kind of infrastructure nobody notices until it’s slow or broken. Getting Apple Silicon support out within weeks of the M1 launch, and closing out the Flash era cleanly rather than leaving it dangling, are both the kind of unglamorous execution that matters more than it gets credit for.

Flash itself deserves a moment here too. For the better part of two decades it was how the web did video, games, and animation before HTML5 caught up — YouTube ran on it, entire genres of browser games were built on it, and now it’s being switched off with barely a whimper. Fitting that it’s going out the same month Apple’s new chip architecture is reshaping what “native” even means for desktop software.