An audit tool that shows its sources and its gaps.

Ocellus runs 30 checks against one hostname and reports the answer each public source gave. It runs entirely in the browser, stores no report on a server, and has no account system. The output is a list of measured values, the source behind each one, and an explicit gap wherever a source could not be reached.

It is built and maintained by Zynu. The full source is at https://github.com/izynu/ocellus, including the check registry, the scoring code and the static build that produces this site.

Why it exists

It began as a user experience audit tool, and the first version of that tool did not measure anything. It generated its scores from a seed derived from the URL, so the same address always produced the same report, with contrast failures, dark patterns and grades that no browser had observed. It looked like a measurement and was not one.

This version replaces every generated value with one of two things: a value a named source actually returned, or an explicit statement that the value is not available. A check that cannot run is reported as unavailable and removed from the score, rather than filled in. The result is a narrower tool that claims less, and everything it claims can be traced to the service that supplied it on the method page.

The rewrite is dated November 2026. Where a capability was dropped in the process, such as rendered layout analysis, the report says what it cannot see rather than estimating it.