Give Claude a list of image filenames and it writes SEO-friendly alt text for all of them in one shot.
The prompt
I'm going to give you a list of image filenames from my website. For each one, write a concise, descriptive alt text (under 125 characters) that describes what the image likely shows based on the filename. Prioritise clarity over keyword stuffing — write it as you would for a screen reader user. Here are the filenames:
[paste your list]
Real use case
I had 60 product images with filenames like hero-blue-widget-desk.png. Pasting the list took 10 seconds and Claude wrote all 60 alt texts in one response. Would have taken 2 hours manually.
The problem it solves
Alt text is one of those SEO tasks that's technically simple but brutally tedious at scale. If you have an image-heavy site (product pages, blog posts, resource pages) you'll have hundreds of images with missing or low-quality alt text.
Google uses alt text to understand images, since it can't "see" them. Missing alt text means those images contribute nothing to your rankings. Bad alt text is a wasted opportunity.
How to use it
- Export your image filenames from your CMS, FTP client, or a quick
lscommand in your assets folder - Paste the prompt above into a new Claude chat
- Drop your filename list at the bottom
- Copy the output directly into your CMS or image manager
Works best when filenames are descriptive (e.g. seo-audit-checklist-screenshot.png). For completely generic names like IMG_4823.jpg, Claude will flag them as unresolvable rather than guessing.
Result
Typical output for 50 images takes Claude about 15 seconds. Each alt text comes out appropriately descriptive without keyword stuffing, exactly what Google recommends.