Alt Text Generator
Describe what the image shows and what it is for, and you get three versions of alt text that follow accessibility guidelines: the content and function of the image, no "image of", specific rather than pretty, and within the platform's limit. Charts and screenshots get their data or text spelled out.
Results come from Claude, tuned per platform. Edit them: the best version is the one that sounds like you. We do not store what you type.
Alt text rules
- Describe content and purpose, not appearance for its own sake.
- Skip "image of" and "picture of": screen readers already say it is an image.
- For charts, give the takeaway and the key numbers.
- For text in an image, include the text.
- Decorative images get empty alt text so screen readers skip them.
- Limits: Instagram 100 characters, X 1,000, Bluesky 2,000, LinkedIn 120, most websites no limit but under 125 is the convention.
Frequently asked questions
How long should alt text be?
Under 125 characters for most uses; Instagram caps it at 100. Charts and screenshots can run longer where the platform allows.
Does alt text help SEO?
Yes on websites: image search reads it. On social it is for accessibility and, on some platforms, for the algorithm's understanding of the image.
Is it free?
Yes. Ten generations a day with no account.
Write it here, publish it everywhere
Social by InstantDM schedules to Instagram, Facebook, X, LinkedIn, TikTok, Pinterest, Threads and YouTube from one calendar, with AI captions, previews and an API. Start free — $0 today, cancel anytime.
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