Inside ALI.EXE.

When you run the diagnostic, your browser sends a real request to this site's /api/diagnostic route. The demo below uses sample data, so you can practise reading a request and its response.

Two clocks, kept apart: how long your browser says the request took, and what the server reports in its Server-Timing header. Nothing shows here until you run the diagnostic.

Everything here is either sample data, labelled that way, or a measurement from this running site. The build records each source file with its line range and SHA-256 hash, so you can check it.