Alternatives / Atlas
Looking for an open source Atlas browser alternative? We compared 9 open source browsers, from AI agent browsers to privacy-focused browsers, by license, engine, AI features, and platforms. Only two add AI agents, and the rest are privacy-first browsers you can pair with your own AI tools.
Written by Maxime DERAME
Last updated:
| Alternative | Best for | License |
|---|---|---|
| Ladybird | Independent browser engine | BSD-2-Clause |
| Zen Browser | Customizable Firefox-based browser | MPL-2.0 |
| Helium | Privacy-first Chromium browser | GPL-3.0 |
| ego lite | AI agents using your logged-in sessions | MIT |
| Waterfox | Firefox fork without telemetry | MPL-2.0 |
| LibreWolf | Hardened privacy browser | MPL-2.0 |
| Flow | Spaces and Chrome extensions | GPL-3.0 |
| Browser Operator | Multi-agent AI browser for workflows | BSD-3-Clause |
| Midori Browser | Lightweight privacy browser | MPL-2.0 |
We looked for open-source browsers that overlap with Atlas, OpenAI's AI browser: a full browser with an AI assistant and agents that can act on pages for you. We verified each project's license, recent activity, stars, engine, and platforms in its repository. Atlas is proprietary and tied to ChatGPT, so we separate the browsers with built-in AI agents from the privacy-first browsers that have none. See our methodology for the full criteria.
ego lite and Browser Operator add AI agents: ego lite lets agents act inside your logged-in browser sessions, and Browser Operator offers research and workflow agents with MCP integrations. The other seven are privacy-focused browsers without a built-in assistant, so you would add AI through extensions or separate tools.
ego lite is a Chromium-based browser with isolated agent workspaces and parallel tasks, running on macOS today with Windows in closed beta and Linux planned. Browser Operator is a desktop AI browser for macOS and Windows with Search, Deep Research, and Workflow agents, and you supply your own LLM provider credentials.
ego lite is MIT and Browser Operator is BSD-3-Clause. Ladybird is BSD-2-Clause, Zen, Waterfox, LibreWolf, and Midori are MPL-2.0, and Helium and Flow are GPL-3.0.
Browsers with AI agents still send prompts and page content to whichever model provider you configure, unless you use a local model. Waterfox and LibreWolf ship without telemetry and without remote AI features, and Helium blocks ads and trackers by default.
Browser Operator's last commit was in March 2026 and Flow's in May 2026, so their development is slower. ego lite, Ladybird, Zen, Helium, Waterfox, and LibreWolf are more active. Ladybird is alpha software and not yet ready as a daily browser.
Atlas is a proprietary AI browser from OpenAI that sends page context to ChatGPT and can act on websites for you, with its memory and activity tied to your OpenAI account. Open-source alternatives let you inspect the code, choose your own AI providers or local models, and in many cases avoid AI and telemetry altogether, at the cost of less polished built-in agents.
| Alternative | Engine | License | AI features | Best for |
|---|---|---|---|---|
| Ladybird | Own engine (alpha) | BSD-2-Clause | None | Engine diversity |
| Zen Browser | Gecko (Firefox) | MPL-2.0 | None | Customization |
| Helium | Chromium | GPL-3.0 | None | Privacy with Chrome extensions |
| ego lite | Chromium | MIT | Agent automation | Agents with real sessions |
| Waterfox | Gecko (Firefox) | MPL-2.0 | None | Tab hierarchy and privacy |
| LibreWolf | Gecko (Firefox) | MPL-2.0 | None | Hardened privacy |
| Flow | Chromium | GPL-3.0 | None | Workspaces |
| Browser Operator | AI browser | BSD-3-Clause | Multi-agent | Research and workflows |
| Midori Browser | Gecko (Firefox) | MPL-2.0 | None | Lightweight browsing |
Want AI agents that work in your logged-in sessions
ego lite lets agents share your real browser state, with isolated workspaces, parallel execution, and batch JavaScript actions.
Want a browser with research and workflow agents
Browser Operator adds Search, Deep Research, and Workflow agents with unified memory and MCP integrations, using your own LLM credentials.
Want a privacy-first Chromium browser
Helium blocks ads and trackers by default and supports Chrome and Manifest V2 extensions, with no analytics.
Want a customizable browser with vertical tabs
Zen is a Firefox-based browser with vertical tabs, split views, workspaces, and Zen Mods.
Want maximum privacy hardening without AI
LibreWolf removes telemetry and hardens Firefox with uBlock Origin and fingerprinting protection.
Want an independent browser engine
Ladybird builds a new engine from scratch without Blink, WebKit, or Gecko, but it is alpha software for now.