API· 5 min read
Image API: Programmatic Resize, Compress and Convert
Automate image processing with the resizeimagesfree API. Resize, compress, convert, and generate thumbnails from your backend or scripts.
The web app is great for one-off edits, but if you're processing user uploads at scale — a marketplace, a CMS, a batch pipeline — you want an API. The resizeimagesfree Image API exposes the same resize, compress, convert, and AI-thumbnail engines the web app uses, callable from any language that speaks HTTP.
What you can automate
- Resize by pixels or percentage while preserving aspect ratio.
- Compress to a target KB budget for form uploads or email attachments.
- Convert between JPG, PNG, WebP, and AVIF.
- Generate platform-sized thumbnails (YouTube, Instagram, Open Graph).
Typical integration patterns
- On upload: resize + convert to WebP before storing in S3 or R2.
- On request: generate on-the-fly thumbnails cached by a CDN.
- In a cron: batch-recompress an old bucket to reclaim storage.
Try it now
Ready to put this into practice? Everything runs in your browser — no uploads, no signup.
Open the tool →