Verification method and limits of the measurement
This page sets out how the record is established, which criteria cannot be verified by automatic means, and which errors the instrument produced while being developed.
Outcomes returned by the check
| Outcome | What it means for you |
|---|---|
| C | Checked, your page passes. Nothing to do. |
| NC | Checked, your page fails. A fact, readable in the code your server sends. Indisputable, and therefore fixable. |
| NT | Not testable. Our tool cannot see this criterion. It tells you so instead of counting it as a pass. |
Criteria not verifiable by automatic means
| Beyond any tool | Why |
|---|---|
| Real colour contrast | The page must be rendered to compute it. |
| The keyboard path | Someone must press Tab and watch where they land. |
| What your JavaScript adds afterwards | The page must be executed, not merely read. |
| Whether an alt text is apt | “image1.jpg” is an alt text. It describes nothing. Only a human sees the difference. |
| What a screen reader says | Someone must listen to it read your page. |
That figure is written on every report we deliver. An automatic measurement establishes failures; it never establishes compliance. Compliance established on the word of an automatic tool alone is not actionable.
Conformity wording and served code
The French order of 20 September 2019 requires the wording “Accessibility: fully / partially / not compliant”. We read it and set it against the measurement.
Where a site carries the wording “fully compliant” and its served code contains a verifiable failure, the published statement contradicts the state of the site. It may then be produced in support of the finding of breach.
Errors found in the instrument
On its first run against the live web, our tool reported three failures on a large public-service site that declares itself fully compliant. All three were wrong: a link whose name lived inside an image, a hidden frame no screen reader ever meets, and two top-level headings the standard allows.
The site concerned is not named. All three causes were fixed and fifteen test cases were added to the instrument. A failure reported in error leads to corrections without object and calls the whole record into question.
Our own pages go through the tool and the result is published, failures included: our accessibility statement. It says “not compliant”, because no human audit has taken place here either.
Reproducibility of the check
The tool that produces your results is published. Your IT department, your agency or a competitor can run it against your site and get the same result — today, in six months, at your desk as at ours. No artificial intelligence takes part in the measurement: that is what guarantees two runs give the same figure.
The executable code of the check and its test cases are published: measurement code · test cases · address-guard test cases.
Have your sites measured
Tell us how many sites, and by when. You receive the dated file within five working days: the record, the drafted statement, the remediation plan in order of cost, and the tool to contradict us.