Aside vs Zen

We make Yab, the third column.facts checked Oct 9 ↓

Aside is an AI agent browser from a Y Combinator startup, on Chromium, for Mac and Windows. Its agent does multi-step work in the sites you are signed in to, on Aside’s own models or your ChatGPT or Claude plan.

Zen is a free, open-source browser built on Firefox that brings Arc’s layout, tabs down the side with spaces, folders and Split View, to Mac, Windows and Linux.

The short answer

Pick Aside

if you want an agent for multi-step work across your signed-in sites, on Mac or Windows
if you want a free plan with AI credits, or to bring your ChatGPT or Claude plan
if you want Claude Code or Codex to drive it over MCP or its command line

Pick Zen

if you want Arc’s layout, free and open source
if you prefer Firefox’s engine and its add-ons
if you want no AI in your browser at all

Or Yabours

if you miss Arc and want spaces, pins and folders kept, on a Mac
if you already pay for Claude or ChatGPT and want it to work in your signed-in tabs
if you want Claude Code, Codex or Cursor to drive a real browser over MCP

At a glance

Aside and Zen, with Yab beside them for a Mac.

Aside vs Zen
What	Aside	Zen Browser	Yab
Made by	Aside Computer Inc. (YC Fall 2025)	Zen Browser team (open-source community project)	Serafim Korablev
Status	Updated	Updated	Updated
Runs on	Mac and Windows	Mac, Windows and Linux	Mac
Phone app	None yet; an iPhone app is in the works. Pro runs its agent from Slack or Telegram	None; Zen says it has no plans for a mobile version	Not yet
Price	Free with 500 AI credits a month; Pro $20/month; Max $200/month; or your own ChatGPT or Claude plan	Free and open source	Free; its AI runs on your own Claude or ChatGPT plan
AI	An agent that works in pages, on its own AI or yours	No AI	An agent that works in pages, on your Claude or ChatGPT plan
Driven by outside agents	MCP and a command line	No	MCP and a command line
Engine	Chromium	Gecko	WebKit
Tabs down the side	Yes	Yes	Yes
Spaces	Yes	Yes	Yes
Split View	Yes	Yes	Yes
Extensions	Chrome Web Store	Firefox add-ons	Chrome Web Store
Ad blocker	Built in	No	Built in
Open source	No	Yes	No

Checked October 9, 2026 on each maker’s own pages, linked under Sources. Prices are per month, in US dollars.

Where they differ

What separates them, area by area. Where one plainly has more, it says who; where it comes down to taste, it says so.

AIAside leads

Only Aside has an agent that clicks, types and finishes tasks in your pages. Aside’s agent runs multi-step tasks in your signed-in sites, signs in from its own password vault without seeing the passwords, and asks before payments, posts and messages. Zen has no AI: Firefox’s AI features are switched off by default.

Agents like Claude Code and CodexAside leads

Aside can be driven over MCP and a command line, through the aside command line, with aside mcp as its MCP server. Zen has no MCP server or command line for outside agents.

Tabs and windowseven

Both have tabs down the side, spaces, Split View, folders in the sidebar and tabs that sleep.

PriceAside leads

Aside: Free with 500 AI credits a month; Pro $20/month; Max $200/month; or your own ChatGPT or Claude plan. Zen: Free and open source.

Where it runsZen leads

Aside runs on Mac and Windows. Zen runs on Mac, Windows and Linux. On a Mac, Aside needs macOS 15 or later and Zen needs macOS 10.15 or later. Aside has no phone app yet: an iPhone app is in the works. Pro runs its agent from Slack or Telegram. Zen has no phone app: Zen says it has no plans for a mobile version.

Engine and extensionsa matter of taste

Aside is built on Chromium, as Chrome is; Zen on Gecko, Firefox’s engine. Aside takes extensions from the Chrome Web Store, Zen from Firefox’s add-ons.

Privacyeven

Aside has an ad blocker built in. Aside keeps task transcripts and files on your Mac; model providers get the prompts, page snapshots and screenshots a task needs, and analytics sharing is on by default. Zen has open code. Zen sends no telemetry or crash reports, by its privacy policy; optional sync keeps encrypted data on Mozilla’s servers.

What their pages don’t lead with

Real limits, from the makers’ own words and our own use.

Aside

The free plan has 500 AI credits a month; more is Pro at $20 or Max at $200
Mac (macOS 15 or later) and Windows only, no phone apps
Young: first released in February 2026, on Windows since September 2026
Agents may use your saved passwords unless you change the default

Zen Browser

Releases are still labeled beta
No phone app, and none planned
Firefox add-ons only, not the Chrome Web Store
No ad blocker of its own beyond Firefox’s tracking protection

Yab, honestly

Mac only: macOS 15.4 or later, no Windows, iPhone or Android
New: first released in September 2026
Its AI needs a Claude or ChatGPT plan; ChatGPT’s free plan may work with low limits
WebKit, as in Safari: a site tested only in Chrome can misbehave
Closed source

What changed lately

September 21, 2026Aside: Ad blocking with default filter lists turned on during setup
September 14, 2026Aside: Windows version officially available (release 1.0.914.1)
September 5, 2026Zen: Spaces, folders and tabs sync between devices with a Mozilla account (1.22b)
February 28, 2026Zen: Live folders for GitHub issues, pull requests and RSS (1.19b)
February 25, 2026Aside: First Aside Browser release for macOS
August 27, 2025Zen: Tab folders added (1.15b)

Questions

Is Aside free?

Yes, with limits on its AI. Free with 500 AI credits a month; Pro $20/month; Max $200/month; or your own ChatGPT or Claude plan.

Is Zen Browser free?

Yes. Free and open source.

Which has an AI agent, Aside or Zen?

Aside. Aside’s agent runs multi-step tasks in your signed-in sites, signs in from its own password vault without seeing the passwords, and asks before payments, posts and messages. Zen has no AI: Firefox’s AI features are switched off by default.

Do Aside and Zen run on Windows?

Yes, both. Aside runs on Mac and Windows; Zen on Mac, Windows and Linux.

Do Aside and Zen have phone apps?

Aside has no phone app yet: an iPhone app is in the works. Pro runs its agent from Slack or Telegram. Zen has no phone app: Zen says it has no plans for a mobile version.

Is there a third option on a Mac?

Yab, Yet Another Browser, is free for the Mac: tabs down the side with spaces, folders and Split View, as in Aside; an agent in your signed-in tabs like Aside’s, on the Claude or ChatGPT plan you already pay for. Claude Code, Codex and any MCP client can drive it too. It runs on WebKit, the engine Safari uses, and takes Chrome extensions. It is Mac only, and new.

More comparisons

Aside vs Dia Aside vs Comet Aside vs Atlas Aside vs Opera Neon Aside vs Chrome Aside vs Safari Aside vs Edge Aside alternatives Yab vs Aside Zen vs Arc Zen vs Vivaldi Orion vs Zen SigmaOS vs Zen Zen vs Chrome Zen vs Safari Zen vs Edge Zen alternatives Yab vs Zen

Sources, read October 9, 2026. Something out of date? Write to hello@serafimlabs.io and we fix it.

Yab, Yet Another Browser.

Free for the Mac. Arc’s sidebar, your own Claude or ChatGPT as the agent, Chrome extensions on WebKit.

it’s freeMove from Aside Download