Side-by-side comparison · AI Browsers & Agents
Firefox vs Opera One vs Comet
Everything that matters when choosing between them, in one place: our rating, what each can do, what they cost, and the trade-offs.
Comparing 3 tools, the maximum.
At a glance
Pick it if: Business owners who want a trusted, independent browser and want to decide for themselves whether AI is on or off.
Pick it if: Anyone who wants a free Chrome alternative with a capable AI sidebar, tab organisation and a built-in VPN, without paying for anything.
Pick it if: Anyone who researches, compares or reads a lot online and wants an AI helper in the browser without paying for it.
Overview
| Attribute | Firefox | Opera One | Comet |
|---|---|---|---|
| In one line | Mozilla's free browser with optional AI you can switch off with one setting. | Opera's free everyday browser with a built-in AI sidebar that reads your tabs. | Perplexity's free web browser with an assistant that reads your tabs and does tasks. |
| Pricing model | Free | Free | Freemium |
| Starting price | Free | Free | $5/mo |
| Free plan | Yes | Yes | Yes |
| Works with Claude Code | No | No | No |
Rating breakdown
Our scores out of 5. The higher bar in each row is highlighted.
| Attribute | Firefox | Opera One | Comet |
|---|---|---|---|
| Overall rating | 3.6 | 3.9 | 3.9 |
| Ease of useHow quickly someone non-technical gets value from it. | 3.5 | 4.5 | 4.5 |
| FeaturesHow completely it covers its own job, and how well the pieces fit together. | 3.0 | 3.0 | 4.0 |
| Output qualityHow good the results are before you fix them. | 3.5 | 3.5 | 3.5 |
| Value for moneyWhat you get for the price, including the free plan. | 4.5 | 4.5 | 4.0 |
| Speed & reliabilityHow fast it is and how often it falls over. | 3.5 | 4.0 | 3.5 |
Feature comparison
A tick means it does this today. A dash means we haven't checked.
| Attribute | Firefox | Opera One | Comet |
|---|---|---|---|
| Access & platform | |||
| Free plan | Yes | Yes | Yes |
| Mobile app | Yes | Yes | Yes |
| Desktop app | Yes | Yes | Yes |
| Browser extension | No | No | Yes |
| API access | No | No | No |
| Teams & business | |||
| Team workspace | No | No | Yes |
| Enterprise plan or SSO | Yes | No | Yes |
| Connects to other apps | Yes | Yes | Yes |
| Open source or self-hosted | No | No | No |
| AI abilities | |||
| Works with your files | No | Yes | Yes |
| Understands images | No | Yes | Yes |
| Makes images | No | Yes | No |
| Makes video | No | No | No |
| Writes code | No | No | No |
| Runs agents or automations | No | No | Yes |
| Learns your brand or style | No | No | No |
| Works in many languages | Yes | Yes | Yes |
| Capabilities score | 6/ 17 | 8/ 17 | 11/ 17 |
Pricing
Plans as listed on each vendor's site when we last checked. Confirm before you buy.
| Attribute | Firefox | Opera One | Comet |
|---|---|---|---|
| Plans | FirefoxOur pick Free Everyone, with AI on or off as you choose. | Free Free Everyone. There is no paid tier for the AI. | FreeOur pick Free Everyday browsing with an assistant for summaries and questions. |
Smart Window beta Free Heavy researchers in the US, Canada or France. | Free with an Opera accountOur pick Free Anyone who wants chat history across devices and more images. | Comet Plus $5/mo Readers who want partner publishers' paywalled articles. | |
Perplexity Pro $20/mo, or $200/yr Anyone who wants the agent to do tasks for them. | |||
Perplexity Max $200/mo, or $2,000/yr Heavy users running many tasks in the background. | |||
| Which plan to pick | There's nothing to pay. Use the sidebar with whatever AI account you already have. If you're in the US, Canada or France, try Smart Window with a free Mozilla account. Everyone else can join the waitlist. | It's all free. Sign in with a free Opera account if you want your chats saved and more images; otherwise just download it and click Ask AI. Opera sells a separate VPN Pro, but you don't need it for the AI. | Use it free: the sidebar assistant alone is worth having, and most people never need more. Pro makes sense if you want Perplexity's research tools anyway, but don't buy it just for the browser agent, since Pro's credits are a one-off bundle. Nobody needs Max just for the browser. |
Key features
| Attribute | Firefox | Opera One | Comet |
|---|---|---|---|
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Pros and cons
| Attribute | Firefox | Opera One | Comet |
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Who each one is for
| Attribute | Firefox | Opera One | Comet |
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Questions people ask
Which is better, Firefox, Opera One or Comet?
They tie on our overall rating (Firefox 3.6/5, Opera One 3.9/5 and Comet 3.9/5). Firefox is best for Keeping AI out of the browser entirely and using your own ChatGPT or Claude in a sidebar. Opera One is best for summarising long pages and YouTube videos and comparing suppliers or products grouped in a Tab Island. Comet is best for summarising long pages, PDFs and videos and comparing products or suppliers across tabs.
Which is cheaper, Firefox, Opera One or Comet?
Firefox: It's free and open source. Opera One: It's free to use. Comet: There's a free plan, and paid plans start at $5/mo.
How we compare
Ratings are our own, from using each tool, across ease of use, features, output quality, value for money, speed & reliability.
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