Captchas and accessibility
2026-10-03 · Captcha basics
A picture-only test excludes people who cannot see it. Audio and simpler questions were added for that reason.
The first captchas assumed a person who can see and type. Distorted letters fail that assumption for a blind visitor, and a faint low-contrast image fails it for many other people. A test that a portion of the public cannot complete is a blocked door, not a security check.
Audio captchas were the usual repair. The site speaks a short code through noise, and the visitor types it. That helps someone who can hear and type, and it fails someone who is deaf and blind, or who is in a place where they cannot play sound. Audio captchas describes the clip. This API does not transcribe it.
Other sites ask a plain question, such as a small sum written as real text in the page, or they offer a checkbox with an accessible name. A sum that is already text in the HTML does not need an image reader. Read the DOM. Call an OCR API only when the challenge is painted into a picture.
If you run a form, put the captcha on the route that is abused, offer a path a screen reader can use, and keep the image's text alternative honest. An empty alt on the only challenge means the accessible name of the page is a blank.
Captcha OCR is a reader for images you already have. It is not an accessibility layer for a checkbox vendor. For the images it does read, the types page is the map.
Ready to call it? Start with the quickstart, the API guide, or pricing.