Images have clear, descriptive text alternatives
What this criterion checks
This criterion maps to 1.1.1 Non-text Content. A detailed plain-language description is maintained in the WebLens criteria catalogue; the WCAG sub-test breakdown below describes exactly what the agent checks and what it does not.
How it's assessed
WebLens walks each user journey, captures a screenshot at every step, and an agent reasons over that evidence. See the how WebLens works for the full pipeline and the deterministic checks layered in for accessibility.
Sub-test coverage
1.1.1 Non-text Content is broken into 7 sub-tests. Coverage is honest about where the agent is reliable, where it only partially checks the requirement, and where a human reviewer is still needed.
3 partial4 not covered
- Controls and inputs have descriptive namesPartial
Our tool checks that image-based inputs (input type="image") have accessible names. Broader control naming checks (buttons, links, form controls) are covered under our WCAG 4.1.2 test (accs-tech-accessible_names).
- Decorative content is hidden from assistive technologyPartial
Our tool checks that img elements either have alt text (informative) or are marked as decorative (role="presentation" or role="none"). However, it cannot determine whether a given image is truly decorative or informative, and does not cover decorative content beyond img elements (e.g., CSS background images, decorative SVGs without img role).
- Informative images have equivalent text alternativesPartial
Our tool checks that img, input type="image", object, SVG (with img role), and elements with role="img" have text alternatives present. It also verifies that meter and progressbar widgets have accessible names. However, it can only detect the presence of alt text — it cannot evaluate whether the text alternative serves an equivalent purpose. Human judgment is required to assess alt text quality.
- CAPTCHA has description and alternative formsNot covered
Requires human judgment to verify CAPTCHA elements have text descriptions and alternative forms for different sensory modalities. Not automatable.
- Sensory content has descriptive identificationNot covered
Requires human judgment to identify sensory content (e.g., art, music) and verify descriptive identification is provided. Not automatable.
- Tests and exercises have descriptive identificationNot covered
Requires human judgment to identify test/exercise content and verify descriptive identification is provided. Not automatable.
- Time-based media has descriptive identificationNot covered
Our tool's checks for this test ID focus on image and widget alt text. Descriptive identification of time-based media (audio/video) under 1.1.1 is not checked. Media-specific checks are under our 1.2.x tests.
How reliable it is
This criterion is still building up testing data, so confirm its findings as you review. See Accuracy & confidence for how the confidence tags are set.