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How long should alt text be?
There is no hard limit, but most good alt text is a sentence or two, often under about 125 characters. Describe what matters about the image in its context, not every detail.
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Open the character counterAlt text: the numbers
| Shown in full up to about | 125 characters |
|---|---|
| How it counts | Characters as you see them: an emoji or an accented letter is 1. Spaces and line breaks count. |
| English words that fit | 19–22 |
Last reviewed October 2026. Platforms change their limits; when it matters, check the platform’s help pages.
What counts as a character
- Spaces and punctuation count; there is no technical limit in HTML.
- Some platforms do set limits on their image description fields.
Best length vs the maximum
- Say what the image shows and why it is there: the same photo needs different alt text in a news story and in a shop.
- Do not start with “Image of”; screen readers already announce it as an image.
- For a complex chart, give the key finding in the alt text and the data in the text or a table.
- The often quoted 125-character figure comes from old screen-reader behaviour; it is a sensible guide, not a rule.
Questions and answers
Is there a character limit for alt text?
Not in HTML. Keep it concise; if an image needs a long explanation, put it in the page text.
Should decorative images have alt text?
Give them an empty alt attribute (alt="") so screen readers skip them.