Check reference

The Sitebulb Labs Extension has 50 checks in six categories. A normal scan leaves out checks for emerging standards. You can include those in the extension’s settings; they are marked emerging below. They can add bonus points, but missing an emerging signal does not lower a category score.

A check can return one of six statuses:

Status	Meaning	Effect on score
Pass	The check found the signal or a sound configuration	Full credit if scored
Warn	Something is present but incomplete, or needs attention	Half credit if scored
Fail	A problem the check can confirm	No credit if scored
N/A	The check does not apply or there is nothing relevant to assess	Excluded
Info	A finding without a clear pass or fail	Excluded
Unmeasured	The check applies, but the extension could not complete it	Excluded

Some checks are bonus checks. Passing one adds points to the overall score; its absence cannot reduce a category score. The extension calculates category scores from the other applicable checks, then combines those scores with extra weight on Content accessibility and Bot access control. Bonus points are capped at 10. Protocol discovery and Commerce contain only bonus checks, so neither has a category percentage unless scored checks are added in a future version.

The priority panel estimates how many points each fix could add. It draws those estimates from the current scan rather than a fixed list of “easy wins”.

Each check below also shows its Top 100 adoption: the share of the world’s top 100 sites that pass or warn on the check in our weekly scan. Open a check to see the trend and which sites implement it.

Discoverability

Can an agent find the site’s pages, files, and published services?

Content accessibility

Can an agent read and understand the content it finds?

Bot access control

What do the site’s crawl rules say about AI bots and user-triggered agents?

Protocol discovery

Can an agent find an API, tool, or service it can use? All checks in this category are bonus checks.

Agent experience

Can an agent make sense of the page and use its controls?

Commerce

Can an agent transact with the site? All four checks are emerging bonus checks, so an ordinary site is not penalised for lacking them.

Check sets

For most addresses, the extension runs all checks, including content and API checks. Individual checks can still report N/A. For hosts whose first label is api, apis, graphql, or rest, or begins with one of those followed by a hyphen (for example, api-eu.example.com), it skips content-only checks. It does not currently offer a manual check-set selector. You can turn emerging checks on or off in settings; they are off by default.