February 12, 2026
Slideshow smartwatch, comment chaos
Run Pebble OS in Browser via WASM
Old smartwatch OS now runs in your browser — the FPS fight begins
TLDR: Pebble’s old smartwatch software now runs entirely in a web browser using a tool that emulates its hardware. Commenters are split between amazement and frustration over the painfully slow frame rate, with nerds proposing fixes and others gleefully triggering errors—proof browsers can do wild things, if you’re patient.
Your old Pebble smartwatch just crawled back from the 2010s to live inside a browser tab, no downloads needed. A dev compiled QEMU (software that pretends to be a tiny computer) to WebAssembly, so it emulates Pebble’s ARM guts and boots real PebbleOS firmware. Desktop users are poking it; mobile is still wobbly. The crowd? Equal parts jaw-dropped and side-eye.
KetoManx64 gasped about modern browser wizardry, while mmmlinux deadpanned, “Should I be getting more than .2 FPS?” Cue a wave of speed-shaming. Mischief6 posted actual logs—4 FPS, then 1 FPS—and instantly tripped an assertion by just clicking. The console screamed about clocks running too fast, and everyone laughed like they’d overclocked a watch.
Then the tuners arrived. Zb3 argued it could be snappier with native exception handling and by ditching “asyncify,” but that would need JSPI (a new way for JavaScript to talk to system code). They even dropped TempleOS experiments as receipts. Meanwhile, hemmert kept it wholesome: “Pretty impressive!” It’s the perfect internet split—“wow, this is wild” versus “why is my watch OS a slideshow?” Either way, it’s proof browsers are becoming low-key time machines. No servers, no installs, just nostalgia booting in slow motion. Bring popcorn and patience.
Key Points
- •Runs entirely in the browser with no server or installation required.
- •QEMU is compiled to WebAssembly for client-side execution.
- •The system emulates the original Pebble ARM hardware.
- •It boots real PebbleOS firmware rather than a reimplementation.
- •Tested on desktop; does not work well on mobile yet.