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Image SEO checker and optimizer
Find images without alt text, oversized files and missing dimensions, then compress them and convert to WebP or AVIF in a separate directory, with redirects and a task for the developer.
Image SEO checker and optimizer
Image pipeline
In the desktop app: find heavy images in a scan, compress, convert to WebP or AVIF, generate 301 redirects and hand the task over.
Image SEO checker and optimizer
Safe by default
Optimisation writes to a separate directory unless in-place mode is requested, which keeps backups.
Three steps, one saved scan
Find the weak images
A native crawl records each image's file size, its alt attribute and whether it loads. A Screaming Frog export can be analysed offline with seohead sf run.
Compress and convert
images-optimize writes WebP or AVIF to a separate directory, never upscales, and makes a backup before any in-place edit.
Hand over the fixes
sf run --tasks writes a task list for the developer with reproduction steps. Renamed files need 301s from old and new URL pairs via redirects-generate.
Checks in this feature
| Check | What it means | Severity | Evidence |
|---|---|---|---|
IMG_MISSING_ALT | Image has no alt text. Screaming Frog export only: the native crawl does not measure this per image. | Important | Image URL and the pages that use it |
IMG_MISSING_ALT_ATTRIBUTE | The img tag has no alt attribute at all, not even alt="". Native crawl. | Important | Page URL with the count of img tags missing the attribute |
IMG_OVER_KB | Image file is larger than the size threshold, 150 KB by default. Screaming Frog export or native crawl with resource capture. | Important | Image URL, byte size and the limit |
IMG_BROKEN | Image URL answers with a 4xx or 5xx error, so the browser shows nothing. Native crawl. | Important | Image URL, HTTP status and the source page |
IMG_MISSING_DIMENSIONS | The img tag does not declare width and height, so layout space is not reserved. Screaming Frog export only. | Tip | Image URL and the source page |
IMG_ALT_TOO_LONG | Alt text is longer than the configured limit, 100 characters by default. Native crawl. | Tip | Image URL, alt length and the alt text |
One command
seohead images-optimize --files ./images --output-dir ./optimized --format webpInstall first: installation guide. Every command also runs as an MCP tool for AI agents.
From the check registry
IMG_MISSING_ALTIMG_MISSING_ALT_ATTRIBUTEIMG_OVER_KBIMG_MISSING_DIMENSIONS