AI browsers are here and they're not going away.

What started off as a cool gimmick is now quickly gaining consensus as the future of human-internet interaction. In recent months, Opera, Microsoft, and Sigma have all piled in with their own versions recently, and OpenAI and Google are reportedly also doing some secret tinkering.

But the current leaders in the AI browser bust-up, built by relative newcomers, are Dia and Comet, each championing a different vision of how we should be browsing the web in 2025.

The Makers of Dia

The Browser Company (TBC)—creators of the cult-favorite Arc Browser—hardly needs any introduction. Arc was genuinely brilliant at making people rethink what browsers could be, positing itself as "an operating system for the web" rather than just another way to look at websites.

Problem was, that vision mostly wooed power users who loved its creative bits, but left everyone else scratching their heads. Too clever by half, as they say. Dia represents their mulligan – same ambitious vision, but this time wrapped in AI and actually designed for everyday humans.

The Makers of Comet

And Comet, the latest challenger to enter the ring with Dia, is an agentic browser built by Perplexity, Google's adversary in search. Comet is built around Perplexity's search engine and packed with automation tools that promise to handle the tedious bits of web browsing for you.

We've been using both browsers for weeks now, partly out of curiosity and partly because we couldn't decide which one to make our default browser. Read till the the end to find out which we picked.

From our use, we found that while one browser focuses on helping you think faster, the other offers to do the thinking for you.

While we're admittedly longtime Arc fans, we're also just two product guys who enjoy playing with fun new AI toys and tech enthusiasts who stand by the merit of an objective review.

Right then. Let's get into it.

So, what's an AI browser in the first place?

Jeremiah: As with all things AI right now, that's an evolving term.

But I think Tech Now defines it pretty well when they describe an AI browser as "a web browser enhanced with built-in artificial intelligence features that assist users in real-time. Unlike traditional browsers that simply load pages, AI browsers help users understand content, summarize information, suggest related topics, and even perform writing and research tasks — all within the browser itself."

Arinze: Yeah, so if you've used AI chatbots like Claude, ChatGPT and the likes, then, you pretty much get it. Because with that mental model, you can probably picture an AI browser as having one of those bots baked right into your browser.

So the main value-add is that you don't need to open a separate tab to upload whatever you're working on or thinking about to Claude and the likes; you can do it on the same webpage. It sounds simple; and it is. But it's been quite game-changing for me.

What’s the core difference between Dia and Comet?

Jeremiah: Automation vs. cognition. That’s how I see the split. Comet is agentic, meaning it deploys little digital 'workers' that can choose actions and use tools to do your bidding.

This is what makes Comet feel somewhat revolutionary. It works like ChatGPT's agent mode, except instead of mucking about in some throwaway virtual browser, Comet's pulling the strings in your actual browser, right there on your screen.

Sure, we've had automation extensions before, but those were parlor tricks. Unlike those wonky plugins that felt like programming a particularly stubborn toaster, Comet's assistant actually grasps context. It knows you're logged into Amazon, remembers your recent searches and can see all your tabs. It's almost unsettlingly aware.

It’s the kind of browser where you say, “Book me a table for four at 7pm and send my family invites,” and it literally goes through the clicks. The first time I saw the overlay start methodically clicking through a page, I had an “oh, this is nuts” moment. It's like having a reasonably competent intern who happens to live inside your computer.

I've put together a list of clever use cases people are trying out with Comet. Some of these are properly brilliant, and I'll keep adding to it as I stumble across more gems.

Dia takes a different approach. It's built to make you faster, not obsolete. Dia will understand what you're doing, hunt down information, and translate it into plain English—but when it's time to click "Buy" or hit "Send," that's still your call.

Arinze: Not much more to add really but I'd add that while Dia is my go to for projects where I'm doing a lot of multitasking that requires parallel thinking, Comet is my preferred AI browser when I don't want to do as little thinking as possible.

I can tell Comet to order something from Amazon, send a quick email, even dig through my Notion page—all of which, I have done btw—while I’m doing something more important like painting my nails. Watching things be put into my Amazon cart and my shipping address being filled in (I probably shouldn't trust it with this much info, but oh well) was truly magical to experience with Comet.

But if I’m working through something messy, like understanding an economics paper or critiquing what I'm working on on different tabs, Dia wins for me. Dia actually thinks with me (in a 'voice' of my choosing, I might add). While Comet's assistant just gives me matter-of-fact answers, Dia's bot seems to handle nuanced conversation in a way that feels closer to normal human speak.

Okay, let's talk performance. Which is faster and more reliable?

Arinze: Both are really fast ngl. Moving tabs, closing windows, switching tabs, it’s butter-smooth.

Granted, it's newer, but Comet gets buggy a bit more often, especially if the assistant panel is open while you’re trying to browse normally. I’ve had freezes mid-agent task with Comet while Dia’s stripped-down skeleton keeps it lean and stable while working on tasks that require switching between multiple tabs (that would otherwise take me 1.5x longer with Comet).

I did have a week where I basically couldn't use Dia cos it's assistant was just taking too damn long (about 45 seconds instead of the usual 5-7) to think, but that changed after my next update and I'm now back to switching between both.

But since both browsers have given me performance issues, I abstain from this one.

Jeremiah: Same basic experience, which makes sense (they're basically both Chromium under the hood). Both are snappy, but Dia's stability advantage becomes obvious when you're juggling 20 tabs. Comet feels more like Perplexity wearing a browser costume. Not necessarily bad, but means that Comet inherits a lot of Perplexity’s shortcomings.

Comet's voice mode is particularly irritating. The idea of chatting with your browser sounds soooo appealing, but in practice? It's a mess. You end up in this awkward verbal wrestling match with Comet's assistant over who gets to speak, the lag is painful, and the whole thing just feels... dumber somehow. Basic tasks that should be trivial become exercises in patience. My grand dreams of voice-commanding my browser are binned for now.

Comet's agents can also be fascinatingly inefficient and slow1. You'll watch Comet break a simple task into five unnecessarily complex steps that would take you 40 seconds to do manually. Half the time, they run off confidently then completely forget what they were supposed to be doing or just fail altogether after spending 10 minutes on a task.

Oddly, both browsers are kinder to your battery and memory than most. Dia might be the most lightweight browser I've ever used, which is remarkable considering the sheer volume of data these things are processing behind the scenes.

🏆 Verdict: Dia takes the performance trophy.

What is my AI Browser doing with all that data?

Jeremiah: Got an eyebrow raised real high at Comet for this one.

Right now, we're still in "trust me bro" territory when it comes to data. Neither company is being properly transparent about what gets stored long-term, but Comet's approach is particularly controversial. By using the browser and granting it access to other services, your data’s in the Perplexity ecosystem, so you’re tied to their terms.

Comet ships with a native ad blocker (nice touch), but according to it's privacy policy, "Your input and output, such as questions, prompts and other content that you input, upload or submit to the Services" gets hoovered up and kept. Perplexity's CEO Aravind Srinivas openly stated that Comet is designed to collect extensive user data (your online behavior, shopping [*cough, cough* Arinze], travel, browsing habits, prompts) for "hyper-personalized" ads and advanced automation.

It's as personal as data gets, and they're being refreshingly honest about wanting every bit of it. Whether that honesty makes it better or worse is up to you. Arinze?

Arinze: Exactly right. And this "trust me bro" era comes with perks such as free early access to premium features on both browsers, which is why I'm not really complaining lol.

But, unlike other AI browsers, Dia processes your data locally wherever it can, bins your browsing history after 30 days by default, and actually lets you decide what gets shared. At a time when the AI race is incentivizing companies to harvest data with reckless abandon, this approach is very rare, and very welcome.

But there has to be a balance though cos I'd rather they kept my data for longer if it meant I'll always have access to it when I need it. For example, I lost all my Dia Skills when I switched to a different Mac a few weeks ago. But, with Comet, the moment I signed into Perplexity, all my old chats and data were there. That kind of cross-device reliability scored Comet serious points for me.

🏆 Verdict: We’re giving this one to Dia.

Customization is important to me – can I make it really mine?

Arinze: Dia’s the clear winner here for me. With Dia’s style-matching feature, you can set it to write like you do (or you want to write like), so your AI suggestions actually sound like you or a voice familiar to you.

Having physics explained in Beyoncé’s diction? You can’t quite put a price on that. Well, maybe you can, but I'll pay for it every time...even though it's all free on Dia right now.

Comet and Dia both have customizable prompts, called Shortcuts and Skills respectively, but I think I prefer Comet's because it lets you choose from a wider range of models for each shortcut. This is a big win for folks who prefer Claude to ChatGPT for their day-to-day.

Jeremiah: Absolutely. And Dia's Skills feature is easily one of the most creative things happening in this space right now. The Skills Gallery is packed with brilliant—and wonderfully ridiculous—community creations that actually let you bend your browser to work the way you do. Comet spotted this appeal and rushed out their own version called "Shortcuts," but it seems neutered.

Here's an odd quirk though: Dia runs ChatGPT under the hood but won't connect to your personal ChatGPT Plus account (yet). Meanwhile, Comet ties directly into your Perplexity account. It's a strange disconnect.

The bigger issue is that Dia seems to be missing some of Arc's core strengths. Personalization was one of Arc's superpowers – profiles, tab groups, all that organizational wizardry. Right now, Dia's lacking even these basics. I'm hoping they're just getting the AI bits right before porting over the features that made Arc special. Because without them, it feels a bit... naked.

🏆 Verdict: Comet gets this one!

User experience, or: which browser won't drive you completely mental?

Arinze: Comet’s fine, but it’s not the kind of design that makes you excited to open it. It’s basically the Perplexity interface pasted into a browser. Very functional, but a real missed chance to do create a really standout UI, which hasn't been Perplexity's strongest suit if we're being honest.

Dia’s nicer to look at, but that's cos it's a lot less performance-oriented. Dia's floating chat is a big deal for me, and I underestimated it until I switched to Comet, where the chat is locked into this big side panel. Being able to resize the chat window, and move it around based on where I want it at that time is what human-centered design looks like.

Sometimes I want the AI small and subtle, especially when at work when I don’t need a full sidebar screaming “this guy’s chatting with an assistant.” With Dia, I can resize, reposition, even make it feel like a casual messaging window instead of a productivity block.

Jeremiah: Here's my problem with Comet: Perplexity as the default search. Look, I get it – they need to show off their big, shiny AI muscles. But web searching isn't the same as having a chat with ChatGPT. Where Google gives you fifteen different ways to skin a cat, Perplexity serves up three options and calls it a day. Yes, you can hit Shift+Enter for Google, and yes, you can change the settings. But come on, if you can't trust your own search engine to be the face of your browser, what are we even doing here?

Dia solves this brilliantly by intuitively swapping between Search (Google) and Chat (ChatGPT) depending on what you type in. It just groks the right function for your query and picks correctly most of the time. I didn't even notice it at first because it's that seamless—which is exactly how it should be. The Browser Company has always had that “experience-first” mindset, and Dia reflects it. The thing is genuinely lovely to use – the tab management, shortcuts and visual cues all just work. It feels like they've studied how normal people actually use computers, not just how to screw AI onto a browser tab.

Comet's jammed with features, but the whole thing feels inelegant and soulless at times. It's like using enterprise software that happens to be quite clever. Gets the job done, I suppose.

🏆 Verdict: Dia’s the clear winner.

Are these good enough to justify spending actual cash on, or are we all just playing with expensive toys?

Jeremiah: Both tools are genuinely impressive, both are in beta, and both are playing the classic land-grab game while they figure out pricing.

Right now, you're stuck on waitlists for both. But here's where it gets interesting: you can skip Comet's queue by dropping $200 a month on their Max subscription. Two hundred dollars. Per month. That's premium tool pricing for people who really, really want their AI to click buttons for them.

Dia's taking a different approach. They've introduced their first-ever Pro Plan, which probably means rate limits are coming whether we like it or not. Classic Browser Company move: build something lovely, then figure out how to pay for it.

If Dia cracks agentic browsing at a reasonable price, this becomes a no-brainer. Until then, we're all just watching to see who blinks first.

Arinze: If Dia joins Comet to start charging tomorrow (and, as seen below, they are already quietly laying the groundworks for Dia Pro), I’d choose based on three things: customization, speed, and model quality.

Whoever nails all three first gets my subscription. Right now, switching for me is about features not price, which I acknowledge is a privilege.

🏆 Verdict: Dia wins this as well.

Final decision — if you had to pick one today?

Jeremiah: Dia I’m so sorry, but it’s Comet. Can't put the bloody thing down, despite spending half this review bashing it. It just delivers so much value.

It's properly changed how I work online, and I can't bear the thought of going back to regular browser and losing my little digital minions. Worth remembering: these are probably the worst versions of these browsers we'll ever see. They're only getting better from here.

For the technically minded or proper internet power users, you'll probably fall for Comet hard. People are calling Dia "the People's AI Browser," and I quite like that framing. It'll likely stay the simpler, more approachable option for folks who just want their browser to be cleverer without causing friction.

Arinze: Yeah. If you want a ‘digital butler’ of sorts, pick Comet. If you want a sharp assistant that gives you space to think while matching your talking vibe, Dia’s the one. I think most people will end up switching between both browsers.

In 2025, I feel like your browser choice says more about your 'workflow personality' than about browser itself because, at the end of the day, with enough time, feedback, and investment, AI browsers will likely approach the same level of performance.

Until then, it's Comet for me.

Disclaimer: While I (Arinze) have been an on-campus ambassador for both Dia and Comet, this review is not sponsored, endorsed, or influenced by either company. This review reflects my most honest review of both browsers based on my time using them—Dia, since Feb 2025 and Comet since Jul 2025.