Researcher tests 23 browser agents: only Manus signs its requests, pointer movement betrays them all
cogito-ergo-sum_ · reddit · 2026-10-28
A developer building an analytics tool ran the same task through ChatGPT's agent, Claude in Chrome, Comet, Grok, Manus, Browser Use, Playwright MCP, DevTools MCP and more, logging what websites actually see:
- Most agents set navigator.webdriver to false; Playwright MCP disables it, while plain Playwright scripts, agent-browser and DevTools MCP leave it on.
- Manus is the only one that properly identifies itself: Manus-User UA plus a Web Bot Auth signature on every request. ChatGPT's agent signed requests in 2025 but sent no signature in these runs.
- Comet sometimes runs locally, sometimes in a Windows/AWS cloud browser for the same page, contradicting its own explanation.
- Grok's browser came from the user's own IP/timezone but reported Linux x86, 8 cores, no GPU on an Apple Silicon Mac.
- Click timing doesn't separate agents from humans (80–450ms holds); what gives every clicking agent away is the pointer jumping onto the target in one step instead of arriving in small moves.
- The old "console.log an error and check if CDP reads it" trick detects nothing in Chrome 136–156.
A hands-on reference for anyone doing bot detection or agent identity work.
Related event: Only Manus Signs Honestly Among 23 Browser Agents Tested(2 posts)→
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