Rio vs Arc

Rio keeps Arc's sidebar: spaces, pinned tabs, folders and favorites. Arc stopped getting new features in May 2025 and stops working on December 22, 2026. Rio is free, open source under GPL-3.0 and built on Chromium 158. It runs side panel extensions, needs no account, and imports your Arc setup in one step.

Updated November 12, 2026.

Side by side

	Rio	Arc
Sidebar	Spaces, pinned tabs, folders, favorites and Today tabs	The original sidebar with spaces
Still adding features	Yes, 7 releases from November 10 to 12, 2026	No new features since May 2025
Works after December 22, 2026	Yes	No, Arc stops working
Chrome Web Store extensions (MV3)	Yes	Yes
Side panel extensions	Yes, on the right next to the page	No
Open source	Yes, GPL-3.0	No
Account	Not needed	Required; new accounts closed October 22, 2026
Speedometer 3.1, Chrome = 100	97.8, our run on one Mac	91.0, from BrowseRating's scores on a different Mac
Memory added by the same 10 sites	3,573 MB, mean of 3 runs	5,385 MB, 1 run on a profile with extensions

Every Arc cell comes from the sources at the end of this page. Rio's cells come from Rio's own release notes, source code and measurements.

Where Rio is ahead

It keeps working. Arc stops working on December 22, 2026. Rio updates itself and shipped 7 releases between November 10 and 12, 2026.
Side panel extensions. Extensions built on Chrome's side panel open next to the page in Rio. Arc does not support them.
Open source. Rio's code is on GitHub under GPL-3.0. Arc's maker said it can't open-source Arc without also open-sourcing ADK, the closed engine Dia runs on.
No account. Rio runs without one. Arc needs one, and new Arc accounts closed on October 22, 2026.
Speed and memory. Rio scored 97.8 on Speedometer 3.1 against Chrome on our Mac; BrowseRating's scores put Arc at 91.0% of its Chrome score. With the same 10 sites open, Rio added 3,573 MB of memory and Arc added 5,385 MB.

How the speed and memory 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. Arc's 91.0 comes from BrowseRating's published scores, 47.5 for Arc 1.167.1 and 52.2 for Chrome, on a Mac whose model BrowseRating does not publish.

The memory numbers come from one overnight run on the same MacBook Pro, with the same 10 public sites opened in each browser. Rio ran 3 times on an empty test profile. Arc ran once on the maker's own profile with his extensions and tabs, so its idle memory was higher and only the memory added by the sites compares.

Moving over

Rio imports your Arc spaces, profiles, pinned tabs, folders, favorites, Today tabs, bookmarks, history, saved passwords and sign-ins in one step, reading Arc's files on your Mac. The walkthrough is in Move from Arc to Rio. The full table with Dia, Chrome, Safari and Comet is on the home page.

Download Rio for Mac

Questions

Is Rio a copy of Arc?

No. Rio is an independent project that contains none of Arc's code. It keeps the sidebar layout Arc made popular: spaces, pinned tabs, folders and favorites.

Is Rio faster than Arc?

Rio scored 97.8 on Speedometer 3.1 against Chrome's 100, in 3 runs each on one Mac. BrowseRating's scores put Arc 1.167.1 at 91.0% of its Chrome score, on a different Mac.

Does Rio use less memory than Arc?

On one MacBook Pro with the same 10 sites open, Rio added 3,573 MB (mean of 3 runs) and Arc added 5,385 MB (1 run). Arc ran on a profile with extensions, so only the added memory compares.

Can I use both until Arc shuts down?

Yes. Rio reads Arc's files without changing them, so Arc keeps working as before until December 22, 2026.