| FMRS | 58 / 100 · C | 78 / 100 · B | 76 / 100 · B |
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| Reliability | 10 / 20 | 13 / 20 | 13 / 20 |
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| Security and permissions | 8 / 20 | 12 / 20 | 12 / 20 |
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| Maintenance | 13 / 20 | 18 / 20 | 17 / 20 |
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| Documentation | 14 / 20 | 18 / 20 | 17 / 20 |
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| Setup experience | 13 / 20 | 17 / 20 | 17 / 20 |
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| Best for | - Local Firefox automation
- Web debugging and development workflows
- Users of Claude Code, Claude Desktop, Cursor, or Cline
| - Scenarios where an AI assistant needs to actually drive a browser to complete a task
- Web automation testing and end-to-end verification
| - Frontend developers who want AI-assisted web debugging and performance analysis
- Scenarios that need browser automation and performance diagnostics in the same tool
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| Not for | - Environments without a local Firefox installation
- Situations where an agent must not access browser-reachable content
- Cloud-hosted execution environments
- Direct use with a normal daily-browsing profile
| - Simple static-text scraping (a lightweight scraper is a better fit)
- Environments sensitive to browser resource usage that can't run a full browser engine
| - Cases that only need to scrape page text without performance analysis or complex interaction (a lighter scraping tool is a better fit)
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| Required permissions | - Requires access to a local Firefox browser and sites it can reach.
- A dedicated Firefox profile is recommended; when connecting to an existing browser, the agent can access cookies, logged-in sessions, and open tabs.
- The `prefs` and `privileged` modules require `MOZ_REMOTE_ALLOW_SYSTEM_ACCESS=1` and are available only in the Mozilla-internal build.
- Firefox for Android mode requires adb on PATH and a connected Android device.
| - Requires installing and running a browser engine (Chromium/Firefox/WebKit) locally or on a server
- browser_navigate can visit any URL; browser_evaluate can run arbitrary JavaScript in the page context
| - Requires a local Chrome browser instance to run
- navigate_page can visit any URL; type_text/fill_form and similar tools can enter arbitrary content into the page
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| Risks and side effects | - Browser automation servers carry inherent risk and may expose cookies, saved sessions, and browser-reachable content.
- Web pages may contain prompt injection intended to manipulate the agent; use sites you control or trust.
- The developer preset enables script and debugging tools, while the mozilla preset additionally expands access to privileged contexts.
- Connecting to an existing Firefox uses a real browsing session; leaving Marionette enabled during normal browsing can expose navigator.webdriver and trigger bot detection.
| - browser_evaluate executing arbitrary scripts carries risk if a malicious page is visited — restrict to trusted sites or an isolated environment
- Long-running browser instances consume significant memory and CPU
| - Browser automation tools can access and manipulate the content of open pages — use only in a trusted development/test environment
- performance_start_trace and similar tracing tools continuously record browser activity — avoid leaving them running on pages containing sensitive information
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| Supported clients | Claude Code, Claude Desktop, Cursor, Cline | Claude Desktop, Claude Code, VS Code, Cursor, Windsurf, JetBrains, Zed, Cline, Amp, Kiro, LM Studio, Antigravity, Goose | Claude Code, VS Code, Cursor, Windsurf, JetBrains, Cline, Amp, Kiro, Antigravity |
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| Tools | 28 | 10 | 22 |
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