Show HN: Open source alternative to Perplexity Comet
1 day ago (browseros.com)
Hey HN, we're a YC startup building an open-source, privacy-first alternative to Perplexity Comet.
No invite system unlike bunch of others – you can download it today from our website or GitHub: https://github.com/browseros-ai/BrowserOS
--- Why bother building an alternative? We believe browsers will become the new operating systems, where we offload much bunch of our work to AI agents. But these agents will have access to all your sensitive data – emails, docs, on top of your browser history. Open-source, privacy-first alternatives need to exist.
We're not a search or ad company, so no weird incentives. Your data stays on your machine. You can use local LLMs with Ollama. We also support BYOK (bring your own keys), so no $200/month plans.
Another big difference vs Perplexity Comet: our agent runs locally in your browser (not on their server). You can actually watch it click around and do stuff, which is pretty cool! Short demo here: https://bit.ly/browserOS-demo
--- How we built? We patch Chromium's C++ source code with our changes, so we have the same security as Google Chrome. We also have an auto-updater for security patches and regular updates.
Working with Chromium's 15M lines of C++ has been another fun adventure that I'm writing a blog post on. Cursor/VSCode breaks at this scale, so we're back to using grep to find stuff and make changes. Claude code works surprisingly well too.
Building the binary takes ~3 hours on our M4 Max MacBook.
--- Next? We're just 2 people with a lot of work ahead (Firefox started with 3 hackers, history rhymes!). But we strongly believe that a privacy-first browser with local LLM support is more important than ever – since agents will have access to so much sensitive data.
Looking forward to any and all comments!
I didn't realize you all had changed your name and I'd already installed Nxtscape and thought something was wrong when I opened up BrowserOS and saw the same UI and fox emoji icon in the chat. btw I'm not gonna lie, I liked your old name better. I'm guessing you changed it for legal reasons?
I tested it out asking it to summarize the comments of an Arstechnica article and at first it said:
> I am unable to summarize the comments as the provided page content only contains the article itself, not the comments section. The extract tool does not appear to be able to access the comments on this page.
I had to tell it to click on the "comments" link for it to actually start going through the comments. For reference, there's 3 pages of comments and it's taken more than 20 minutes and performed around 100 actions, with lots of those actions being scrolling down a very specific 1074 pixels. I am currently sitting here still waiting for the actual summary while it says "Validating task completion..."
Seems like it could be powerful, but the hand holding required and extremely slow speed make it unusable for me at this point.
Since I had Nxtscape installed, I tried the same experiment and it successfully did it in less time with fewer actions. Not sure if that's just random chance or if there's different logic running under the hood.
One final note: There's a Chrome extension that lets you use your iCloud passwords in Chrome and it doesn't work in either Nxtscape or BrowserOS. I'm not likely to use a browser that requires regularly having to go into my password manager to manually retrieve usernames and passwords, and I'm not changing my password manager for this.
Yeah, decided to change the name to avoid any troubles. Also, previous name was hard to pronounce :)
Thank you for the feedback. Would love to chat more on discord (https://discord.gg/YKwjt5vuKr) and help you with your use-cases! we are shipping daily and improving things fast, agent should get much better in a few days.
> There's a Chrome extension that lets you use your iCloud passwords in Chrome and it doesn't work
Will check it out! We definitely want to make onboarding and password mgmt much easier!
The demo buying toothpaste shows the difficulty of these tasks. Toothpaste itself was very underspecified, and it essentially randomly chose from a huge list. Some tasks may have past actions that could help guide, others won't have any to inform. Failure cases abound -- maybe the toothpaste you previously bought is no longer available. Then what? Ultimately how much time did this particular example save since you need to double check the result anyway? This is what doomed Alexa for the purchasing experience that Amazon assumed it would enable in the first place.
I think it'd be better to show more non-trivial examples where the time savings is clear, and the failure cases are minimized... or even better how it's going to recover from those failure cases. Do I get a bespoke UI for the specific problem? Talk to it via chat?
This whole world is non-trivial. Good luck!
Great points! For sure, the whole agentic browsers space is still super early.
We are also just getting started and trying to narrow down on a high-value niche use-case.
There are few repetitive, boring use-cases where time saving could be meaningful -- one example: Walmart 3rd-party sellers routinely (multiple times a day) keep checking prices of the competitor products to price their products appropriately. This could be easily automated with current agentic browsers.
But in reality, would much more consistently be automated by a single playwright script.
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If this is a privacy first browser, why wasn´t Firefox used when it is much better out of the box for this approach? All security and privacy focused webbrowser use Firefox. Like Tor Browser, Mullvad Browser, LibreWolf etc.
Also, I think it is super important we have different "webbrowser engines" and that are independent from big tech companies. If we only have chromium it would be really bad and hurt use consumer really bad and also stop inovation.
We really need to support independentCbrowsers like Firefox more.
This was definitely a hard choice.
We spoke to folks who had built browser on top of webkit and they spent nearly 2years just fixing random bugs and getting sites to work. I'm sure firefox/gecko engine would probably work better than webkit, but the point still is: if we don't use chromium, a lot of work does have go into fixing website compatibility issues, adding support for extension. We're 2 person startup and chromium codebase was easier to build on top of and provides a solid baseline.
And Brave has shown that you can build a privacy-focused browser on top of chromium still.
In the agentic browser era, I think there are so many low hanging fruits on privacy which are more important to address -- sending all your sensitive data to Perplexity Comet to sell ads is a pretty bad option right now. Supporting local LLM, letting folks bring their own API keys is crucial.
I had exactly the same question.
You're privacy focused but use chrome as the engine?
> --- How we built? We patch Chromium's C++ source code with our changes, so we have the same security as Google Chrome. We also have an auto-updater for security patches and regular updates.
So you rebuild your browser on every Chromium release? Because that's the risk: often changes go into Chromium with very innocent looking commit messages than are released from embargo 90 days later in their CVE reference
Good question, so far we have been building on top of chromium release that Google Chrome is based on.
I feel as though you overlooked the "every" word in my question. I appreciate you built once, that's a solid accomplishment. If I'm going to be riding your custom build, with your custom C++ changes that introduce their own RCE risk, I want to at least know I'm only vulnerable to your RCE and not your RCE plus the 'just disclosed' RCE for Chromium itself that was actually patched 3 weeks ago but that you didn't bother to track because you don't track Chromium release tags
Yes, I'm acutely aware of exactly how much compute pulling off such a stunt requires; what I'm wondering is whether you are aware of exactly how much RCE risk you're running by squatting on someone else's C++ codebase that ships what feels like a vuln-a-week from one of the best funded security research teams in the world
You build from the release branches yeah? So, right now that'd be the 7204 branch. https://chromiumdash.appspot.com/releases?platform=Mac
I would prefer this as a browser extension, not as its own browser application.
We would've preferred to build this as browser extension too.
But we strongly believe that for building a good agent co-pilot we need bunch of changes at Chromium C++ code level. For example, chromium has a accessibility tree for every website, but doesn't expose it as an API to chrome extension. Having access to accessibility tree would greatly improve agent execution.
We are also building bunch of changes in C++ for agents to interact with websites -- functions like click, elements with indexes. You can inject JS for doing this but it is 20-40X slower.
How is that accessibility tree different from the “accessibility snapshot” that you can get from Playwright for example?
I was tackling a similar problem few weeks ago and I found that playwright MCP was the most usable solution in my case. It doesn’t use an extension but it debugs the browser tabs (I guess using dev tools protocol) but I agree the experience was suboptimal
Could you upstream that change in order to make it an extension in the future? I think people would not value it any less.
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Would this be possible for Firefox?
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I mean you could build the agent with a first principles understanding of the DOM instead of just hacking together with the accessibility tree
We had this exact thought as well, you don't need a whole browser to implement the agentic capabilities, you can implement the whole thing with the limited permissions of a browser extension.
There are plenty of zero day exploit patches that Google immediately rolls out and not to mention all the other features that Google doesn't push to Chromium. I wouldn't trust a random open source project for my day-to-day browser.
Check out rtrvr.ai for a working implementation, we are an AI Web Agent browser extension that meets you where your workflows already are.
Brave Browser (70M+ users) has validated that a chromium fork can be viable path. And it can in fact provide better privacy and security.
Chrome extensions is not a bad idea too. Just saying that owning the underlying source code has some strong advantages in the long term (being able to use C++ for a11y tree, DOM handling, etc -- which will be 20-40X faster than injecting JS using chrome extension).
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> I wouldn't trust a random open source project for my day-to-day browser.
Given that you're working on a direct competitor, this comment reads as fearmongering, designed to drive people over to your product.
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Exactly my thoughts when I saw nanobrowser being mentioned here.
try https://github.com/nanobrowser/nanobrowser
> We are also building an LLM-based ad-blocker after Chrome blocked uBlock Origin.
Since it's a Chromium fork, why not re-enable uBlock Origin instead?
Chromium will remove the Manifest V2 APIs, and none of these forks want to maintain them. Brave also chose to have their own built-in adblocker.
The real question is, why not opt to fork Firefox who is doing that work for them.
+1, enabling uBlock origin could be a short term solution.
But we are working on adding built-in adblockers just like Brave + enhancing it to detect more ad formats using lightweight local LLM.
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I want to see the mouse cursor moving and clicking, and keys typed by the AI appearing onscreen in realtime like you see in software product tutorials.
The jumpiness of pages switching and things changing when an AI is driving is extremely disorienting. I find it hard to follow a thread of continuity in the page flashes and ui changes as the bot acts.
Right now it’s like watching a screen recording with no hint as to what I’m “supposed” to be focusing on.
Regardless - I have use cases for this in the mcp/browser automation vein another user mentioned so super interested to see where this goes.
This is very useful feedback, thank you!
We will look into add a cursor movements; key typing should already appear like a human would (but probably we can slow it down a bit).
Want you really want is a caretaker ai
I’m unclear what it is you’re describing. I’m describing UI affordances.
This is similar to the chrome extension nanobrowser. https://github.com/nanobrowser/nanobrowser
Hm just saw this.
I think if something can be done as an extension then there is no need to do it as a fork of the existing software.
Are there any differences b/w nanobrowser and brwoserOS? like some functionalities that only browserOS could do and not nanobrowser which are worth mentioning?
thanks for the mention!
Whats the roadmap looking like for Linux?
I don't have Mac or Windows.
this is on our radar, we plan to have it ready by early next week!
still a team of 2 people, so bunch things on our plate.
Congrats!
How are you planning to make the project sustainable (from a financial, and dev work/maintenance pov)?
Thank you!
plan is to sell licenses for Enterprise-version of browser, same as other open-source projects.
my guess is it's just an electron app or chromium wrapper with an ollama wrapper to talk to it (there are plenty of free open source libs to control browsers).
We are a chromium "wrapper"
But we are much more performant than other libs (like playwright) which are written in JS, as we implement bunch of changes at chromium source code level -- for example, we are currently implementing a way to build enriched DOMtree required for agent interactions (click, input text, find element) directly at C++ level.
We also plan to expose those APIs to devs.
“Just” is a four-letter word :)
When someone in their infinite wisdom decides to refactor an api and deprecate the old one, it creates work for everyone downstream.
Maybe as an industry we can agree to do this every so often to keep the LLMs at bay for as long as possible. We can take a page out of the book of the maintainers of moviepy for shuffling their apis around, it definitely keeps everyone on their toes.
You don’t have to guess, it’s open source
No wireless. Less space than a Nomad.
Love the direction here. Local-first, open-source agentic browsers feel inevitable as AI gets more deeply embedded in our workflows. Watching the agent actually click around (vs. black-box cloud APIs) is both reassuring and fun. Curious how you’re handling Chromium’s relentless update pace with such a small team -- Does patching ever break in unexpected ways? Rooting for you; privacy-centric infra like this is long overdue.
Thank you for the support!
So far our patches have not conflicted with chromium updates. But there are viable ways to do patching and keep up with the pace (Brave Browser has pretty example infra setup to do this).
This is very exciting given the rumor that OpenAI will be launching a (presumably not open source) browser of their own this summer. I've joined your Discord, so will try it soon and report back there. Congrats on launching!
Thank you!
Browser wars have begun.
> that OpenAI will be launching a (presumably not open source) browser of their own this summer.
For sure, won't be open-source. I bet in some parallel world, openAI would be non-profit and actually open-source AI :)
> Browser wars have begun.
Kind of a sad browser war. The majority of these Chromium forks should exist, nor are they particularly viable. Sniffing out which one is going to be successful is obviously the hard problem.
Ideally we'd get an extensions API for AI agents and various companies could just release their own plugins. Sadly I don't think the majority is interested, they want to control the "experience".
Would love to see this show up on homebrew!
Oooh, that's a nice idea! We'll look into doing that!
Making a homebrew recipe is super easy, and you can definitely find an example to draw from that's "shaped" like your app. Highly recommend.
This is not Open source alternative to Perplexity Comet
This is the real thing, the original if you will.
As for Perplexity, to me this company and line of product are seemed as the alternative to anything great in AI.
Haha, thank you!
As a small startup we cannot outspend Perplexity Comet in marketing, so we just said open-source alternative so that people get what we are building.
The name is confused. I think it is a web-based OS in the first place.
Hmm, what do you mean? Could you elaborate? Thanks!
I mean the name "BrowserOS" made me think it is an Operating System. Congrats to your achieved.
> our agent runs locally in your browser (not on their server)
That's definitely a nice feature. Did you measure the impact on laptop battery life in a typical scenario (assuming there is such a scenario at this early stage)
The agent running by itself shouldn't impact battery life, it is similar to a lightweight chrome extension and if you think about it, it's an agent browsing the web like human would :)
If you run LLMs locally (using Ollama) and use that in our browser, that would impact battery life for sure.
The windows .zip shared on your github release page gets flagged as a Trojan by windows defender. Why is it a zip in the first place?
It is just a warning. We working on getting Microsft Windows signing set up.
Is BrowserOS-OS on the roadmap?
(Will you ever make a better FydeOS, or if you're laser-focused, perhaps be open to sharing some with them, so they could?)
Yes! We are excited to build BrowserOS-OS! I think with agents the whole UX can be re-imagined.
I'll check out FydeOS!
What is your future revenue model?
Sell licenses for enterprise browser
Is there a way to hook BrowserOS up as a sub-agent for an orchestration agent/system?
Yes! We want to do this.
We were thinking of implement MCP protocol into the browser, so the browser can be an MCP server (that exposes bunch of tools -- navigation, click, extract) and you can connect that to your agent, would that work?
What is your use-case? Happy to chat on discord! https://discord.gg/YKwjt5vuKr
Yes, that works for me! My primary use case is automated testing of updates to websites that I maintain.
Thanks for the discord invite! My username is Mindcast on discord.
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This looks like a great project.
What are the system requirements? And shouldn't they be listed on your website?
we support Mac (apple silicon and intel) and Windows.
hardware requirements are minimal, same as Google Chrome, if you BYOK API keys for agents and are not running LLMs locally.
Do you have any benchmarks to share like Halluminate's Web Bench?
We working on it! Should have pretty soon!
How does the competition do with the same demo tasks?
The demo looks like a mediocre solution looking for a problem. I can order toothpaste without an LLM faster and more reliably.
> But we strongly believe that a privacy-first browser with local LLM support is more important than ever – since agents will have access to so much sensitive data.
How does this make money? Surely this will have a cloud offering?
But if it doesn't make money, I can only assume that the team will be acqui-hired to answer that question.
> How does this make money? Surely this will have a cloud offering?
Our plan is to make the consumer version of the browser for free and sell licenses for enterprise version.
This is similar to how many open-source projects sustain development.
And enterprise browsers are picking up -- Island browser, Talon browser.
> Our plan is to make the consumer version of the browser for free and sell licenses for enterprise version.
Makes sense and the software license chosen (AGPL-3.0) also makes sense as well.
Sounds like a clear path to monetization and much better than some of the VC backed browser-first companies out there.
Good luck.
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What is the default BrowserOS model? Is it local, and if so, what inferencing server are you using?
The default model is Gemini.
You can bring your own API keys and change the default to any model you local.
Or better run model locally using Ollama and use that!
The default is a remote Gemini call?
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What a joke project! Chromium has a over 35 million lines of code. These people applied a few patches on it, and then advertising it as if they have developed a new browser. The same goes for Comet also.
From their GitHub readme:
> but Chrome hasn't evolved much in 10 years
Really?? It is not true. You guys please go and check release notes and commits log for Chrome/Chromium project for the past 10 years.
Maybe they're only refering to the frontend/UX. It's true that in 10 years it has not changed much compared to the diff with browserOS.
First of all, they didn't say they are referring to the UI.
The main element in a web browser's UI is the web view where web pages get rendered. It may look the same 'rectangle' as it used to look 10 years ago. But the way chrome renders web pages and execute JavaScript have undergone a lot of changes over the years. Also they have added a lot of new standard and nonstandard HTML, CSS and JavaScript features. Then, there is WebGL 2.0, WebAssembly, WebGPU, etc.
> joke project
Is Chrome an agentic browser at 35 million lines of code? That's what this project does. Whether they're successful at that or not is another story.
So would this or any AI browser go out and fetch a list of the best deals for my trip to Iceland? After Show me all the options it has found for flights, hotels, car rentals and show cheapest/best prices with all details (fly out of and into with times) to even allow me to pay for each item on same page I asked it to do so? As well it could group the overall best deal with details and then i can just click to pay instantly and or make some edits.
We just started cooking, very soon you should be able to do this!
It seems that the next evolution of SEO will be too skip the SE and simply O for the LLMs.
Orbitz.com has done this for 20 years.
I can ask Orbitz with one question without going to Orbitz to say create me a full itinerary with the best prices for my Iceland trip?
That's advantage of LLMs you dont have to go to the websites and soon you can just talk to your LLM like chatGPT or an advanced Siri to do this and boom it does all the research and shows you the top deals for you to purchase with a click (after you reviewed the prefered one and or talk to the LLM who makes the updates/edits you need before u do one click purchase).
If I was Orbitz I would be begging to work with Open AI / chatGPT (use Orbitz API) before Open AI does it themselves. Website visitation is and going to be dropping precipitiously along with the field of web design and development. That's my own field but it's so clear to me as technological evolutions that get adopted are the ones that reduce steps and make things easier to more magical.
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A word of advice, you're a new account and all your comments are about your service, that is why they are marked "dead," ie users will not see them, it's an anti spam measure. Spend more time actually engaging with the community rather than treating HN like a marketing channel and they won't be dead in the future.