Success Criterion 1.1.1
Conformance level A

CAPTCHA Challenge With No Text-Based Way to Solve It

1.1.1 — Non-text Content

Scenario

Setting

A podcast app's review form

What’s wrong

The review form's spam check is a visual-only CAPTCHA: an image of distorted characters with a text field, and no audio (or other) challenge for the same purpose. The image has an instructional alt, but 1.1.1 still requires another CAPTCHA modality so people who cannot see the image can pass the same check.

Example

<img src="captcha.png" alt="Type the characters you see">
<input type="text" name="captcha_answer">
<!-- visual challenge only; no audio or other modality for the same check -->

Why it matters

A blind listener trying to leave a review cannot attempt the CAPTCHA at all, because the only version offered is an image they cannot see. An instructional alt names the task, but without a second modality they are locked out of posting.

How to test

Find every CAPTCHA. Confirm a text alternative identifies it as a CAPTCHA / human check and describes the task (G143) — for example "Type the characters you see". Then confirm the page also offers another CAPTCHA for the same purpose in a different modality (G144), such as an audio challenge or a simple text question. A visual-only (or audio-only) CAPTCHA with no alternate modality fails 1.1.1. With a screen reader, tab to the alternate control and confirm you can complete the check without seeing the image.

How to fix

For CAPTCHA, 1.1.1 needs both a text alternative that describes the purpose (G143) and another CAPTCHA for the same purpose in a different sensory modality (G144). Keep a clear alt on the visual challenge, and add an equivalent audio (or other) option — for example a "Listen instead" control that plays the challenge. Going further, offer more than two modalities or a human bypass for users who cannot use either form.

<img src="captcha.png" alt="Visual CAPTCHA challenge">
<button type="button" aria-label="Play audio version of this challenge">Listen instead</button>
<input type="text" name="captcha_answer" aria-label="Enter the characters you see or hear">

Outcome

A blind listener activates "Listen instead", hears the audio challenge, types what they hear, and posts their review unaided. Sighted users can still solve the visual version.

Who is affected

Blind and low-vision users, and anyone using a screen reader, who cannot complete a visual-only CAPTCHA. People who cannot hear need the visual path to remain available; some users (including deafblind people) may still need a further modality or a human bypass.