It's close: Comet edges it 8.2 to 8.1, so the right pick depends on what you need. Comet wins on 3 of the 5 scores, Dia on 2.
Researchers and heavy web users who want AI help beside every tab
Office workers who juggle email, docs and meetings in the browser
Score by score
The details
| Feature | Comet | Dia |
|---|---|---|
| Category | AI Assistants | AI Assistants |
| Category rank | #10 of 16 | #12 of 16 |
| Developer | Perplexity AI | The Browser Company |
| Pricing | Free + paid plans | Free + paid plans |
| Usable for free | Yes | Yes |
| iPhone & iPad | ✓ | — |
| Android | ✓ | — |
| Mac | ✓ | ✓ |
| Windows | ✓ | ✓ |
Common questions
Is Comet better than Dia?
It's close: Comet edges it 8.2 to 8.1, so the right pick depends on what you need. Comet wins on 3 of the 5 scores, Dia on 2.
Which is cheaper, Comet or Dia?
Comet: Free on every platform; Perplexity Pro ($20 a month) and Max raise the limits. Dia: Free browser has no AI; Better Answers is $10 a month and Better Days $100. On value for money, Comet scores higher.
Do Comet and Dia work on the same devices?
Only Comet runs on iPhone & iPad, Android.
Which is more private, Comet or Dia?
Dia scores higher on privacy (8.2/10). History, chats and files are encrypted on your device, and Sync is end-to-end encrypted. AI partners can't train on your data. Dia keeps some unlinked content 30 days to improve itself unless you opt out.
Strengths and weaknesses
Comet
- Free on Mac, Windows, iPhone and Android
- Can act on pages, not just sum them up
- Your sessions sync between phone and computer
- A synced account lets Perplexity record your browsing history
- The helper has to read the pages you visit
- No Linux version
Comet is Perplexity's web browser, with an AI helper beside every tab. It can sum up a page or compare products across sites. It can even work through a multi-step task while you browse. Bigger jobs go to Perplexity Computer. It's free on Mac, Windows, iPhone and Android, and your sessions sync between them. The trade-off is privacy. The helper has to read your pages, and a synced account lets Perplexity record your history.
Full Comet review
Dia
- Calm, uncluttered design from the makers of Arc
- Data is stored and encrypted on your device
- AI partners are barred from training on your data
- New users' free plan has no AI features
- Better Days plan costs $100 a month
- Windows version is still an early build
Dia comes from the team behind Arc and puts an AI chat beside your tabs that can read what's open and pull in context from Slack, Notion and Teams. Its Morning Brief, meeting prep and deck building are aimed squarely at office work. Privacy is better than most AI browsers, with your data stored on your device. Since August 2026, though, new users get no AI on the free plan, and the Windows version is still young.
Full Dia review
