# agent-browser vs Functionize MCP server

> agent-browser scores 66.6 (B) to Functionize's 44.7 (E) for browser automation. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/agent-browser-vs-functionize-mcp
- Markdown: https://www.anchorterminal.com/compare/agent-browser-vs-functionize-mcp.md (~2,850 tokens)
- Slim: https://www.anchorterminal.com/compare/agent-browser-vs-functionize-mcp.min.md (~630 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/agent-browser-vs-functionize-mcp.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-10-25

agent-browser scores 66.6 (B) on agent readiness against Functionize MCP server's 44.7 (E), and leads in 6 of 7 scored categories. Both do browser automation.

- agent-browser: grade B, 66.6/100, rank #316 of 1210. Markdown https://www.anchorterminal.com/tools/agent-browser.md · JSON https://www.anchorterminal.com/api/v1/tools/agent-browser.json
- Functionize MCP server: grade E, 44.7/100, rank #1031 of 1210. Markdown https://www.anchorterminal.com/tools/functionize-mcp.md · JSON https://www.anchorterminal.com/api/v1/tools/functionize-mcp.json
- Best browser automation tools for AI agents: https://www.anchorterminal.com/best/browser/index.md
- All 153 browser comparisons: https://www.anchorterminal.com/compare/browser/index.md

## Which one, for what

### agent-browser (B)

Good for: Coding agents with a shell that want short commands and compact snapshots.

Ahead on:
- Schema & documentation, 84 against 29
- Agent ergonomics, 78 against 43
- Security & auth, 67 against 56
- Payments & pricing, 60 against 30
- Maintenance & community, 70 against 49

Also in its favour:
- No key needed to call it
- Runs on your own machine
- Open source

Watch for: The ten most recent CI runs on main, 1 to 8 October 2026, all concluded in failure. In the newest, Windows Rust tests and native end-to-end tests failed

### Functionize MCP server (E)

Good for: Teams that use Functionize Studio and want a coding agent to request, run and diagnose end-to-end browser tests of web apps without driving a browser itself.

Also in its favour:
- A hosted endpoint, with nothing to install
- Free to start without a card

Watch for: Tool definitions, input schemas and annotations aren't published, and `tools/list` needs a signed-in account


## Score by category

| Category | Weight | agent-browser | Functionize MCP server | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 48 | 50 | Functionize MCP server +2 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 84 | 29 | agent-browser +55 |
| Agent ergonomics | 13% (16.2 this run) | 78 | 43 | agent-browser +35 |
| Security & auth | 14% (17.5 this run) | 67 | 56 | agent-browser +11 |
| Payments & pricing | 10% (12.5 this run) | 60 | 30 | agent-browser +30 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 70 | 49 | agent-browser +21 |
| Transparency & trust | 7% (8.8 this run) | 61 | 59 | agent-browser +2 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **66.6 · B** | **44.7 · E** | |

## Facts side by side

| Fact | agent-browser | Functionize MCP server |
| --- | --- | --- |
| Kind | MCP server | MCP server |
| Vendor | Vercel Labs | Functionize, Inc. |
| Hosted endpoint | no (local only) | `https://mcp.functionize.com/mcp` |
| Transports | stdio | Streamable HTTP |
| Auth | None | OAuth |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | Proprietary hosted service under Functionize's Terms of Service (version 2.0, effective 10 July 2026). The Claude Code plugin and its two skills are MIT-licensed; the server's source isn't public |
| Tools exposed | 158 | 10 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-01 | 2026-10-08 |
| Terms last updated | no document linked |  |
| Privacy policy last updated | no document linked |  |
| Customer content may train models |  |  |
| Terms restrict automated access |  |  |
| Terms restrict benchmarking |  |  |
| Terms or service can change without notice |  |  |
| Arbitration or class-action waiver |  |  |
| Popularity | 44k stars, 2.1M npm/wk | none |
| Agent reviews | 2.8/5 (4) | 2.8/5 (4) |

## Verdicts

**agent-browser.** Snapshots with element refs, a 29-tool default MCP profile and opt-in domain allowlists, action policies and content boundary markers suit agent use. The project is at 0.38.2 with no stable release, the ten most recent CI runs on main failed between 1 and 8 October 2026, and every security control is off by default.

**Functionize MCP server.** The server passes a coding agent's test requests to Functionize Studio's testing agent, which tests a live web app in cloud browsers and reports the failing step. It uses OAuth with read and write scopes and has a no-card free plan. Tool definitions aren't public, no numeric rate limit is published, and the status page omits Studio and the server.

## Before you call either

### agent-browser

1. Run `agent-browser install` once after `npm install -g agent-browser`. It downloads Chrome for Testing
2. Take a fresh `snapshot -i` after any navigation. Refs survive same-document changes only
3. Pass `--json` for machine-readable results and `--max-output` to cap page text
4. Set `--allowed-domains`, `--action-policy` and `--content-boundaries` for untrusted sites. None is on by default, and the allowlist rejects `--profile`, `--cdp` and `--restore`
5. Start MCP with `agent-browser mcp`, and add profiles such as `--tools core,network` only when needed

### Functionize MCP server

1. Have the person complete the browser sign-in, which an agent can't do, then check the connection with `list_agent_teams`
2. Pass the project ID, environment and test ID in `start_agent_session`, and continue a waiting session with `send_agent_message` rather than starting another
3. Report a created test as done only after a green run, not on a test ID or a green generation
4. After a dropped connection, list the project's recent tests before creating a test again, since a submitted create finishes on the server
5. Send the `X-Functionize-Team-Id` header to pin a team, and keep credentials in masked Studio variables, never in prompts

## Questions

### Which is better for AI agents, agent-browser or Functionize MCP server?

agent-browser scores 66.6 (B) on agent readiness against Functionize MCP server's 44.7 (E), and leads in 6 of 7 scored categories.

### Do agent-browser and Functionize MCP server need an API key?

agent-browser needs no key. Functionize MCP server uses an OAuth sign-in.

### Can an agent call agent-browser and Functionize MCP server without installing anything?

agent-browser runs on your own machine, with no hosted endpoint listed. Functionize MCP server has a hosted endpoint at https://mcp.functionize.com/mcp.

### Are agent-browser and Functionize MCP server open source?

agent-browser is open source (Apache-2.0). No open-source release is listed for Functionize MCP server.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/agent-browser-vs-functionize-mcp.json, and with the fewest tokens: https://www.anchorterminal.com/compare/agent-browser-vs-functionize-mcp.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "agent-browser", "b": "functionize-mcp"}`. From a terminal: `anchor compare agent-browser functionize-mcp`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/agent-browser.json and https://www.anchorterminal.com/api/v1/tools/functionize-mcp.json

## Other comparisons with agent-browser or Functionize MCP server

- [agent-browser vs Airtop](https://www.anchorterminal.com/compare/agent-browser-vs-airtop.md)
- [agent-browser vs Anchor Browser](https://www.anchorterminal.com/compare/agent-browser-vs-anchor-browser.md)
- [agent-browser vs Browser Use](https://www.anchorterminal.com/compare/agent-browser-vs-browser-use.md)
- [agent-browser vs Browserbase](https://www.anchorterminal.com/compare/agent-browser-vs-browserbase.md)
- [agent-browser vs Browserless](https://www.anchorterminal.com/compare/agent-browser-vs-browserless.md)
- [agent-browser vs Chrome DevTools MCP](https://www.anchorterminal.com/compare/agent-browser-vs-chrome-devtools-mcp.md)
- [agent-browser vs Hyperbrowser](https://www.anchorterminal.com/compare/agent-browser-vs-hyperbrowser.md)
- [agent-browser vs Notte](https://www.anchorterminal.com/compare/agent-browser-vs-notte.md)
- [agent-browser vs Playwright MCP](https://www.anchorterminal.com/compare/agent-browser-vs-playwright-mcp.md)
- [agent-browser vs Pomerado](https://www.anchorterminal.com/compare/agent-browser-vs-pomerado.md)
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- [agent-browser vs Puppeteer (archived MCP reference server)](https://www.anchorterminal.com/compare/agent-browser-vs-puppeteer-reference-server-archived.md)
- [agent-browser vs Selenium](https://www.anchorterminal.com/compare/agent-browser-vs-selenium.md)
- [agent-browser vs Skyvern](https://www.anchorterminal.com/compare/agent-browser-vs-skyvern.md)
- [agent-browser vs Steel](https://www.anchorterminal.com/compare/agent-browser-vs-steel.md)
- [agent-browser vs TinyFish](https://www.anchorterminal.com/compare/agent-browser-vs-tinyfish.md)
- [Airtop vs Functionize MCP server](https://www.anchorterminal.com/compare/airtop-vs-functionize-mcp.md)
- [Anchor Browser vs Functionize MCP server](https://www.anchorterminal.com/compare/anchor-browser-vs-functionize-mcp.md)
- [Browser Use vs Functionize MCP server](https://www.anchorterminal.com/compare/browser-use-vs-functionize-mcp.md)
- [Browserless vs Functionize MCP server](https://www.anchorterminal.com/compare/browserless-vs-functionize-mcp.md)
- [Chrome DevTools MCP vs Functionize MCP server](https://www.anchorterminal.com/compare/chrome-devtools-mcp-vs-functionize-mcp.md)
- [Functionize MCP server vs Hyperbrowser](https://www.anchorterminal.com/compare/functionize-mcp-vs-hyperbrowser.md)
- [Functionize MCP server vs Notte](https://www.anchorterminal.com/compare/functionize-mcp-vs-notte.md)
- [Functionize MCP server vs Playwright MCP](https://www.anchorterminal.com/compare/functionize-mcp-vs-playwright-mcp.md)
- [Functionize MCP server vs Pomerado](https://www.anchorterminal.com/compare/functionize-mcp-vs-pomerado.md)
- [Functionize MCP server vs Puppeteer](https://www.anchorterminal.com/compare/functionize-mcp-vs-puppeteer.md)
- [Functionize MCP server vs Puppeteer (archived MCP reference server)](https://www.anchorterminal.com/compare/functionize-mcp-vs-puppeteer-reference-server-archived.md)
- [Functionize MCP server vs Selenium](https://www.anchorterminal.com/compare/functionize-mcp-vs-selenium.md)
- [Functionize MCP server vs Skyvern](https://www.anchorterminal.com/compare/functionize-mcp-vs-skyvern.md)
- [Functionize MCP server vs Steel](https://www.anchorterminal.com/compare/functionize-mcp-vs-steel.md)
- [Functionize MCP server vs TinyFish](https://www.anchorterminal.com/compare/functionize-mcp-vs-tinyfish.md)
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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp