SecondDoor and Lighthouse Agentic Browsing
Chrome's own agent-readiness checks, inside the audit tool developers already run.
Claims about Lighthouse Agentic Browsing checked August 2026. Their site.
What it is
Lighthouse 13.3, shipped with Chrome 150 in May 2026, added an experimental Agentic Browsing category: accessibility-tree integrity, layout stability under automation, and WebMCP registration, scored as a pass ratio of four checks.
It is the strongest possible signal that agent readiness is becoming a mainstream performance discipline. Four checks is not an audit, but Lighthouse categories grow, and this one ships inside the browser every frontend developer already uses.
What it does well
- Zero setup for anyone who already runs Lighthouse, including in CI.
- Accessibility-tree checks catch rendering problems that page-level scanners miss.
- Backed by the Chrome team, so its checks will track where the browser itself is going.
Choose Lighthouse Agentic Browsing when
- You are a frontend engineer wiring agent-readiness checks into CI next to performance budgets.
- You care about page-level rendering quality for agents rather than the business funnel.
What SecondDoor measures that it does not
- The business funnel: Lighthouse audits a page, SecondDoor walks from the homepage to a checkout or signup and reports where each visitor type stopped.
- The protocol surface (llms.txt, MCP, robots, structured data), which Lighthouse does not check.
- The human comparison and scheduled monitoring.
Side by side
| Capability | SecondDoor | Lighthouse Agentic Browsing |
|---|---|---|
| Scans the site as a human visitor | Yes | No |
| Walks the funnel as an AI agent | Yes | No |
| Scores the human to agent gap | Yes | No |
| Checks the protocol surface (llms.txt, MCP, robots) | Yes | Page-level only |
| Screenshot evidence of the walk | Deep scans | No |
| Tracks citations in AI answers | No | No |
| Public leaderboard | Yes | No |
| Generates ready-to-serve fix files | Yes | No |
| Scheduled rescans with regression alerts | Yes | Via CI |
| Price | Free scan; monitoring from $29/mo | Free |
Common questions
Should I use Lighthouse or SecondDoor?
Both, for different jobs. Run Lighthouse in CI to keep pages technically sound for automation. Run SecondDoor to find out whether the funnel those pages form actually admits an agent, and whether it admits one as readily as it admits a person.
The comparison that settles it is your own site. A free scan takes about a minute and the report is permanent.
Scan your site