Rio vs Comet
Rio and Comet are both Chromium browsers for Mac that run Chrome Web Store extensions. Rio keeps Arc's sidebar of spaces and imports it in one step, opens your pick of ChatGPT, Claude or Grok from the command bar, and is open source under GPL-3.0. With the same 10 sites open in our test, Rio added less memory.
Side by side
| Rio | Comet | |
|---|---|---|
| Sidebar | Spaces with pinned tabs, folders, favorites and Today tabs | Profiles; vertical tabs not documented |
| Arc import | Spaces, profiles, pinned tabs, folders, favorites, Today tabs, history, passwords and sign-ins | Bookmarks, passwords, cookies, history and extensions; spaces not listed |
| Split view | 2 to 4 pages | 2 tabs |
| Asking an AI | Your pick of ChatGPT, Claude or Grok from the Ask row | Perplexity's Comet Assistant; the browser agent is not in the free plan |
| Speedometer 3.1, Chrome = 100 | 97.8, our run on one Mac | 95.0, from BrowseRating's scores on a different Mac |
| Memory added by the same 10 sites | 3,573 MB, mean of 3 runs | 4,157 MB, mean of 3 runs |
Every Comet cell comes from Perplexity's help center or the benchmark sources listed at the end, except the memory row, which is our own run.
Where Rio is ahead
- Arc's sidebar. Rio keeps spaces, each with its own pinned tabs, folders, Today tabs, colors and profile, and swipes between them. Comet's help center describes profiles and does not document vertical tabs. See Spaces.
- Arc, brought over whole. Rio's import brings your spaces and everything in them in one step. Comet's import help lists bookmarks, passwords, cookies, history and extensions. See Move from Arc to Rio.
- The assistant you already use. Rio's Ask row opens ChatGPT, Claude or Grok with your question, signed in to your own account there. Comet's assistant is Perplexity's, and its browser agent is not included in Perplexity's free plan. See Ask.
- AI that stays on your Mac. Rio's tab tidying, short titles, download names and link summaries run on Apple's on-device model. Comet's help center says requests that use your page content, history or open tabs are stored for up to 30 days.
- Four pages at once. Rio's split view holds up to four pages; Comet's holds two. See Split view.
- Open source. Rio's code is on GitHub under GPL-3.0.
- Speed and memory. Rio scored 97.8 against Chrome on our Mac; BrowseRating's scores put Comet at 95.0% of its Chrome score, on a different Mac. With the same 10 sites open on one MacBook Pro, Rio added 3,573 MB of memory and Comet added 4,157 MB.
How the numbers were taken
Speedometer 3.1 scores depend on the Mac, so each number is an index against Chrome on the same machine. Rio's 97.8 is our own run: Rio 158.0.8127.18 against Chrome 156.0.8078.81, 3 runs each, on an Apple M4 Max with 36 GB, November 9, 2026. Comet's 95.0 comes from BrowseRating's published scores, 49.6 for Comet 153.0.8010.49 and 52.2 for Chrome, on a Mac whose model BrowseRating does not publish.
The memory numbers come from an overnight run on November 11, 2026, on one MacBook Pro with an Apple M4 Max and 36 GB. The same 10 public sites opened in each browser on an empty test profile, 3 runs each: Rio 158.0.8127.18 added 3,393 to 3,749 MB, and Comet 156.0.8078.130 added 3,903 to 4,544 MB.
Questions
Can Rio use ChatGPT, Claude or Grok?
Yes. Type a question in Rio's command bar and the Ask row opens the assistant you picked, ChatGPT, Claude or Grok, in a tab with your question. Comet's assistant is Perplexity's.
Does Comet import my Arc spaces?
Comet's import help lists bookmarks, passwords, cookies, history and extensions, and does not mention spaces, folders or pinned tabs. Rio's Arc import brings spaces, profiles, pinned tabs, folders, favorites and Today tabs too.
Which uses less memory, Rio or Comet?
In our test, Rio. With the same 10 sites open on one MacBook Pro, Rio added 3,573 MB and Comet added 4,157 MB, each the mean of 3 runs on an empty test profile.
Where does Rio's AI run?
Tab tidying, short titles, download names and link summaries run on Apple's on-device model on your Mac. Ask sends your question to the assistant you picked only when you choose that row.
Sources
- Perplexity Help Center, Comet browser features
- Perplexity Help Center, Import data into Comet
- Perplexity Help Center, Split-view Mode (two tabs side by side)
- Perplexity Help Center, Comet Assistant Privacy and Data Use
- Perplexity Help Center, Which Perplexity subscription plan is right for you? (Browser Agent row)
- BrowseRating, macOS ARM Speedometer 3.1 rankings (October 3, 2026)
- Rio source, split view holds 2 to 4 panes (split.ts)
- Rio source, the Ask row's assistants (command/ask.ts)
- Rio source, the AI features and Apple's on-device model (AiPane.tsx)
- Rio source code on GitHub (GPL-3.0)
