Firefox in WebAssembly
Creative
browser in browser demo
SHOW HN2026
273points
125comments
#172of 4,366 in 2026
Top 4%of 2026 by points
How HN took it
CuriousMostly questions and neutral comments
7 positive, 42 neutral or asking, 6 mixed, 28 critical, out of 83 comments about the project. Thread score -0.31.
Execution: 1 for, 10 againstPrivacy: 1 for, 8 againstPerformance: 2 for, 5 againstIdea: 2 for, 2 againstPricing: 0 for, 1 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Impressive that it works and performs well
From 2 comments
Oh wow didn't expect this to be either possible or this perform so well. Also fascinating how small the wasm binary is. I made a Wasm port of FreeCad (also had a fairly popular…
devttyeu on HNWorked in my Firefox on Steam Deck. I was amazed it could run YouTube.
koolala on HN
Interesting as a browser-in-browser and sandboxing idea
From 2 comments
Browser sandboxing is now fully solved.
MajesticHobo2 on HNIn mean... It kinda feels like this is legitimately true? An attacker trying to do anything on a user's machine through this would have to find a Firefox vulnerability and a…
yjftsjthsd-h on HN
Objections
Does not work on mobile or in several Firefox setups
From 4 comments
No mobile support
SpyCoder77 on HN... doesn't support Firefox mobile apparently :D
som on HNCan’t get it running on Firefox 152.0.6 (aarch64), no extensions. ``` [chrome-demo] chrome assets ready [gecko] warning: unsupported syscall: __syscall_madvise [gecko] embed-xul:…
brewmarche on HNFirefox ESR in Debian12, won't start. 140.12.0esr (64-bit) This is the entirety of the log message. ``` [chrome-demo] chrome assets + engine wasm ready [gecko] warning:…
thx67 on HN
Single-process mode weakens Firefox sandboxing, so not safe as daily driver
From 2 comments
This is true but also this is probably also only half true. Sandboxing is not a fully solved issue since this 100% degrades firefox sandboxing since fission cant run and its…
rlmineing_dead on HNUnless you're running every origin in a different instance, I wouldn't use this as a daily driver, since a site would only need to find a renderer vuln to be able to read the…
coolelectronics on HN
Routing traffic through a Puter server raises privacy concerns
From 2 comments
All the network traffic from that browser is routed through a server. My IP inside that browser was in India and on CloudFlare network. I don’t particularly trust Puter. Why not…
zerof1l on HN> This is fully end to end encrypted! We use the WISP protocol for TCP-over-websockets. Umm, that doesn't sound right. By definition, i dont think you can be end2end encrypted in…
bawolff on HN
Performance is slow and memory heavy
From 2 comments
I checked internet speed inside and outside the wasm, and inside wasm its 10x slower, what could be the reason?
virajk_31 on HNGreat, looking forward to needing 16GB RAM to watch youtube :(
compass_copium on HN
Requests
Extension support, such as uBlock Origin
From 2 comments
I'm so glad this exists, I've been considering doing something like this for a few months. I recently got a TV based on VIDAA os, a locked-down linux-based OS where everything is…
degamad on HNWe also plan on adding extension support to https://github.com/HeyPuter/browser.js soon, which should hopefully cover use cases like that as well without the full overhead
coolelectronics on HN
Mobile support and working keyboard and touch input
From 1 comment
on mobile chrome / Android I can't get the following to work : - IME / keyboard doesn't pop on any field - copy paste - scrolling with touch - ai side panel What works on mobile…
rmac on HN
Questions
Whether the $25k figure is dollars or tokens, and what it was spent on
From 4 comments
>This port cost over 25k in opus/fable tokens for debugging and JIT research > This was just a fun experiment to push the boundaries of WebAssembly I'm a huge fan of the project,…
yjftsjthsd-h on HNWas it really $25k, or was it done though subscriptions with a reported cost of $25k? I'm on the openai $100 sub and frequently my codexbar will show $250 usage in a day. I think…
tiagod on HNI think it was worded badly it was 25k WORTH of API billed tokens, but only actually 1 claude max 5x plan, so it was more like 100 dollars
rlmineing_dead on HNWhat are the $25k in tokens for? Does firefox's build system not allow building to wasm?
voidUpdate on HN
What the practical use case is
From 2 comments
Impressive and surprisingly performant, but what's the use-case? If anything, this is an ad for WASM!
pmarreck on HNThe description mentions a similar project browser.js which apparently has some real use cases, what are they?
andai on HN
Alternatives named
Browser.js
From 1 comment
WebKit.js and WebkitWasm
From 2 comments
Prior art: WebKit.js, the WebKit rendering engine ported to JS https://github.com/trevorlinton/webkit.js/
azakai on HN$25k of tokens, closer to 30 billion I believe. It only took a few days to actually get the engine up, the hard parts where most of the effort was spent was squeezing out…
coolelectronics on HN
Reynard browser for iOS
From 1 comment
Loosely related to porting the Firefox engine in unusual places: here is a project that ports Firefox's Gecko rendering engine to iOS as a sideloadable app (normally Apple only…
tech234a on HN