A space for each part of your day
Its own tabs and logins. Swipe to switch.
Meet Rio.For people who live in their tabs.
Download for Mac
Free public beta. Apple silicon, macOS 13 or later.
What Rio does
Make it yours
Drag to pin, drop into folders, rename anything.
Two colors per space
The whole window follows.
⌘T for everything
Switch tabs, search, or ask ChatGPT, Claude or Grok.
Side panel extensions
They open beside the page, like in Chrome. Arc doesn't support them.
Downloads and screenshots in the sidebar
Drag any file straight into Gmail, Slack or Finder.
Split view and Peek
Two pages side by side, or a quick look at a link.
Faster than Arc. Lighter than Chrome.
Chrome100.0
Rio97.8
Edge97.1
Safari95.0
Brave94.3
Arc91.0
Dia89.3
Firefox82.0
3,880 MBagainst Chrome's 6,465 MB
RioChromeAll browsers and how we measured
Ungoogled Chromium152.0.7977.64100.4browserating.com, September 6, 2026- Google Chrome154.0.8037.98100.0browserating.com, October 3, 2026
- Rio158.0.8127.1897.8Our run, November 9, 2026
- Microsoft Edge154.0.4258.5397.1browserating.com, October 3, 2026
- Safari27.0.195.0browserating.com, October 3, 2026
Comet153.0.8010.4995.0browserating.com, October 3, 2026
Vivaldi8.2.4133.8094.8browserating.com, October 3, 2026- Brave1.96.6194.3browserating.com, October 3, 2026
Opera136.0.6008.8092.5browserating.com, October 3, 2026- Arc1.167.191.0browserating.com, October 3, 2026
- Dia1.48.0 (86584)89.3browserating.com, September 6, 2026
- Firefox157.082.0browserating.com, October 3, 2026
Zen Browser1.23b76.8browserating.com, October 3, 2026
Orion1.1.367.6browserating.com, October 3, 2026
ChatGPT Atlas1.2026.189.067.4browserating.com, July 26, 2026
Rio: mean of 3 runs (55.5, 55.6, 56.2) over Chrome's mean of 3 (56.8, 56.9, 57.4) on the same Mac, November 9, 2026; the thin band is Rio's slowest to fastest run. Every other bar is BrowseRating's published index against its own Chrome 154.0.8037.98, updated October 3, 2026, mean of the middle 3 of 5 runs; Chrome Canary, a nightly build, is left out. Rio is ahead of 9, level with 3 and behind 4 once every same-machine test is counted.
Rio3,880 MB23 processesChrome6,465 MB41 processesResident memory of every process under each browser profile, 20 seconds after the sixth site opened; one run on the same Mac, November 9, 2026. Lower is better. Arc, Dia and Comet are not in this run.
| Browser | Published index | Mean | Against Rio's 97.8 |
|---|---|---|---|
| Aside | 102.8/81.2 | 92.0 | Rio behind |
 Helium | 98.8/100.5/100.0 | 99.8 | Rio behind |
| Ungoogled Chromium | 100.4 | 100.4 | Rio behind |
| Chrome | 100.0 (our run) | 100.0 | Rio behind |
| Safari | 95.0/98.1 | 96.5 | Level |
| Edge | 97.1/95.6 | 96.3 | Level |
| Brave | 94.3/96.9 | 95.6 | Level |
| Comet | 95.0 | 95.0 | Rio ahead |
| Vivaldi | 94.8 | 94.8 | Rio ahead |
| Dia | 89.3/93.5/91.7 | 91.5 | Rio ahead |
| Opera | 92.5 | 92.5 | Rio ahead |
| Arc | 91.0 | 91.0 | Rio ahead |
| Firefox | 82.0/83.6/85.7 | 83.8 | Rio ahead |
| Zen | 76.8/83.2 | 80.0 | Rio ahead |
| Orion | 67.6 | 67.6 | Rio ahead |
| ChatGPT Atlas | 67.4 | 67.4 | Rio ahead |
Method
Absolute scores from different machines can't be compared, so every number here is an index: a browser's score divided by Google Chrome's score on the same machine in the same test, times 100.
Rio's index is our own run: Rio 158.0.8127.18 and Google Chrome 156.0.8078.81 on one Apple M4 Max, 36 GB, macOS 26.6.2, each on a new throwaway profile, taking turns, 3 runs each, November 9, 2026. Rio averaged 55.8 and Chrome 57.0, so Rio is 2.2% behind Chrome. Memory was read in the same session.
The other indexes are copied as published. BrowseRating does not publish its hardware beyond "Apple Silicon (macOS ARM)", and its Chrome is version 154.0.8037.98 while our run used Chrome 156. The cross-check adds 4 more same-machine tests: Magic Lasso on a MacBook Air 15-inch M2, 16 GB; Aside on a MacBook Pro, Apple M4 Max; Aside on a MacBook Pro 14-inch 2024, Apple M4 Pro; Aside post quoting wukko's run (Helium developer) on a MacBook Pro Mac17,6. Two of them were published by browser makers.
JetStream 2.2 and MotionMark 1.3.1 are not on this page: the only published Mac results (Magic Lasso, January 2026) cover Safari, Chrome, Edge and Firefox, and we have no Rio run of either yet.
Sources
- BrowseRating, macOS ARM Speedometer 3.1 rankings, October 3, 2026. Apple Silicon ("macOS ARM"); chip, model and macOS version not published.
- Magic Lasso, Best web browser 2026, January 8, 2026. MacBook Air 15-inch M2, 16 GB, macOS Tahoe 26.2.
- Macwelt, Schnellster Mac-Browser im Speed-Test, February 21, 2025. Mac mini M1, 8 GB, macOS Sequoia (point version not stated).
- Aside, What Speedometer 3.1 actually measured (Machine A re-run, round 1), August 14, 2026. MacBook Pro, Apple M4 Max, 64 GB, macOS Tahoe, on charger, clean profile.
- Aside, What Speedometer 3.1 actually measured (Machine B), August 14, 2026. MacBook Pro 14-inch 2024, Apple M4 Pro, 48 GB, macOS Tahoe 26.5.2, clean profile.
- Aside post quoting wukko's run (Helium developer), August 13, 2026. MacBook Pro Mac17,6, Apple M5 Max 18-core, 36 GB, macOS 26.6.1, clean profile.
| Feature | Rio | Arc | Dia | Chrome | Safari | Comet |
|---|---|---|---|---|---|---|
| Vertical sidebar with spaces | Sidebar with spaces, pinned tabs, folders and favorites | The original sidebar with spaces1 | Sidebar optional; spaces become profiles1 | Vertical tabs since April 2026; no spaces2 | Vertical tabs in the 27.3 beta only3 | Profiles; vertical tabs not documented4 |
| Imports Arc spaces and pinned tabs | Yes, one click on first launch | Not applicable | Spaces become profiles, folders become tab groups5 | Not documented6 | No Arc import; Chrome and Firefox directly, others by bookmarks file7 | Bookmarks, passwords and history; spaces not documented8 |
| Chrome Web Store extensions (MV3) | Yes | Yes1 | Yes1 | Yes9 | No; Safari extensions from the App Store10 | Most; start-page changes may not work11 |
| Side panel extensions | Yes; the panel opens on the right, next to the page | No12, 13 | Yes, since Dia 1.10.1 (December 2025)14 | Yes, since Chrome 11415 | No; Safari extensions use their own model, without chrome.sidePanel16, 10 | Not verified |
| Open source | GPL-3.0 | No; not open-sourced (May 2025 letter)17 | No17 | No; Chromium is9 | No; WebKit is18 | No public repository |
| Still adding features | Yes | No new features since May 2025; stops working December 22, 202617, 19 | Yes, Mac 1.56.0 on November 5, 202620 | Yes2 | Yes3 | Yes21 |
| Engine and version | Chromium 158.0.8127.18 | Chromium 157.0.8103.5122, 23 | Chromium 15720 | Chromium 157.0.8103.3924 | WebKit18 | Chromium11 |
| Built-in AI agent that acts on pages | No | No; Arc Max chat and tab tools25 | Chat tools that fill forms and use Gmail and Calendar20 | Auto browse preview, US, paid plans26 | No27 | Yes, clicks and scrolls on pages28 |
| Works without an account | Yes | No; new accounts closed October 22, 202629, 19 | No1 | Yes; sign-in is optional30 | Yes | Yes; sign-in can be skipped31 |
Sources
- Arc Help Center, Arc sunset FAQ, October 22, 2026.
- Google, New Chrome productivity features (vertical tabs), April 7, 2026.
- 9to5Mac, macOS 27.3 beta adds vertical tabs to Safari, November 3, 2026.
- Perplexity Help Center, Comet browser features, November 10, 2026.
- Arc Help Center, Move from Arc to Dia, October 22, 2026.
- Chrome Help, Import bookmarks and settings, November 10, 2026.
- Safari User Guide, Import bookmarks and passwords, November 10, 2026.
- Perplexity Help Center, Import data into Comet, November 10, 2026.
- The Chromium Projects, November 10, 2026.
- Safari User Guide, Get extensions, November 10, 2026.
- Perplexity Help Center, Comet extensions, November 10, 2026.
- Page Assist README, Browser Support (Arc: sidebar not supported), November 10, 2026.
- Dust community, Troubleshooting Chrome extension issues in Arc ("Arc doesn't currently support side panels"), May 2, 2025.
- Dia changelog 1.10.1 (side panel extensions render in Dia), December 18, 2025.
- Chrome for Developers, chrome.sidePanel (Chrome 114 and later), November 10, 2026.
- MDN browser-compat-data, sidePanel (Safari: not supported), November 10, 2026.
- The Browser Company, Letter to Arc members, May 26, 2025.
- WebKit, November 10, 2026.
- Arc Help Center, Arc sunset: key dates and what to expect, October 22, 2026.
- Dia changelog (Mac 1.56.0), November 5, 2026.
- Perplexity changelog, What we shipped, March 26, 2026.
- Arc 1.172.2 app bundle: ArcCore.framework 157.0.8103.51, read from the app on a Mac, November 10, 2026.
- Arc Help Center, Arc for macOS release notes, November 5, 2026.
- Google Chrome 157.0.8103.39 app bundle, read from the app on a Mac, November 10, 2026.
- TidBITS, Arc introduces focused AI features, October 6, 2023.
- Google, Gemini 3 auto browse in Chrome, January 28, 2026.
- Macworld, Apple brings vertical tabs to Safari in 27.3, November 3, 2026.
- Perplexity, Comet Assistant puts you in control, November 10, 2026.
- Arc Help Center, Arc for Desktop, October 22, 2026.
- Chrome Help, Sign in and sync in Chrome, November 10, 2026.
- Tom's Guide, How to use Perplexity Comet, November 10, 2026.
Coming from Arc? Bring your sidebar.
Rio reads your spaces and pinned tabs from Arc's files on your Mac.
- 1
Download Rio and open it.
- 2
Click Bring everything over.
What comes over
- Spaces, with names, icons and theme colors
- Profiles
- Pinned tabs and folders
- Favorites
- Today tabs
- Bookmarks
- History
- Saved passwords
- Sign-ins (cookies)
- Default search engine
- Extensions, to reinstall from the Chrome Web Store
The code is open
Rio is open source under GPL-3.0. Building a closed product on it needs a commercial license.
Why I built Rio
If the news of Arc shutting down hit you as hard as it did me and all my friends, then why Rio exists is a no brainer.
I ran my whole day in Arc: 4 spaces, 38 pinned tabs, 29 favorites. When it stopped getting new features in 2025, I tried everything else. None of them kept the sidebar the way I used it, so I built Rio on Chromium 158 and moved my whole setup over in one click.
Rio is built to be the best browsing experience I can make: the sidebar Arc got right, Chrome's speed, and open source, so nobody can shut it down on you.
Next up: sync between Macs, and a notarized build so macOS stops warning on first open.
Download it and bring your Arc setup over.
Questions
Is Rio free?
Yes. It's free to use, and the code is open source under GPL-3.0.
Why does macOS warn me on first open?
Rio isn't notarized by Apple yet. Close the warning, then click Open Anyway next to Rio in System Settings, Privacy & Security.
How does Rio update?
Sparkle checks github.com/Levivajan/rio-releases every hour, and a card in the sidebar offers the signed update. It sends no system profile.
What does Rio send?
No analytics, crash reports or account. On its own it only contacts these:
- GitHub: the update check.
- Google Safe Browsing: a short hash prefix when a page matches Google's list of unsafe sites.
- Your search engine: what you type in the command bar, for suggestions.
- Google's component updater: Chromium parts such as the Widevine plugin.
- Sites in your sidebar: icons for imported tabs, and live folder feeds every 30 minutes, with no cookies.
Tab naming runs on-device. Ask opens ChatGPT, Claude or Grok in a tab.
Which extensions work?
Chrome Web Store extensions, Manifest V3 included. Side panel extensions open on the right, as in Chrome.
Does the Arc import upload anything?
No. It reads Arc's files on your Mac, and macOS asks once before Rio reads Arc's saved passwords.
What do I need?
A Mac with Apple silicon on macOS 13 or later. Rio takes about 360 MB.
Where do I report a bug?
On GitHub. Include your macOS version and Rio's version from About Rio.
Can I build a product on Rio?
Yes, if you release it under GPL-3.0 too. A closed-source product needs a commercial license.