Image button alt text

Silktide finds image buttons in your forms that have no alternative text. An image button with no text alternative gives people who cannot see it no way to know what pressing it will do.

<!-- Problem: no alt attribute -->
<input type="image" src="button.png">

<!-- Problem: empty alt -->
<input type="image" src="button.png" alt="">

<!-- Fixed: the alt text names the action -->
<input type="image" src="button.png" alt="Send message">

Why this matters

An image button (<input type="image">) uses a picture in place of a text label, so its alt attribute is the only name a screen reader can announce. Without it, the button is announced as just "button" or by its filename. A form whose submit button cannot be identified is a form some visitors cannot confidently complete - a direct barrier to enquiries, sign-ups, and purchases.

Unlike ordinary images, a button can never be decorative: it always does something, so it always needs a name.

How to fix it

1. Add an alt attribute that names the action the button performs, such as "Search" or "Send message", as in the example above.
2. Do not leave the attribute empty - an empty alt="" hides the button's name without hiding the button.
3. Alternatively, replace the image button with a <button> element containing real text, which is simpler to style and accessible by default.

How Silktide tests this

1. Find every image button (<input type="image">) on each page.
2. Skip buttons hidden from screen readers.
3. Report each button whose alt attribute is missing or empty.

Buttons whose alt text exists but appears unhelpful are covered by the separate Submit button alt text check.

Learn more

• Understanding Success Criterion 1.1.1: Non-text Content (WCAG 2.2)
• Technique H36: Using alt attributes on images used as submit buttons
• Submit button alt text
• Missing alt text