About Free Image Compressor

Free Image Compressor exists to solve one specific, endlessly annoying problem: a form tells you the image must be under a certain number of kilobytes, and every tool you try only offers a vague quality slider. This site inverts that. You state the size you need, and the software works out how to get there.

How the target size is reached

Your image is decoded into an OffscreenCanvas inside a Web Worker so the interface never freezes. The encoder then runs a binary search across the quality range: it encodes, measures the byte count, and narrows the range until it finds the highest quality that still fits your limit. If even the lowest useful quality is too large, pixel dimensions are scaled down in steps and the search restarts. That two-stage approach is why a 6000×4000 camera photo can reliably land under 50KB.

Why nothing is uploaded

Passport scans, ID cards, exam documents and signatures are some of the most sensitive files people own. A server-side compressor has to receive, write and eventually delete those files, and you have no way to verify the last step. Doing the work in the browser removes the question entirely: there is no upload request, so there is nothing to store or leak. It also means the tool keeps working on a poor connection and costs nothing to run, which is why it can stay free without ads on the tool itself.

Supported formats

• Input: JPG, JPEG, PNG, WEBP, GIF, BMP, AVIF (whatever your browser can decode).
• Output: JPEG, PNG, WEBP.
• Batch: up to 30 files per run, with a ZIP download.

Limitations worth knowing

PNG is lossless, so a PNG output cannot be squeezed to an arbitrary target — the tool switches strategy and reduces dimensions instead, or you can export as JPEG or WEBP. Extremely large images are limited by your device's memory rather than by us. And because compression is lossy, re-compressing an already compressed file repeatedly will visibly degrade it; always start from the original where you can.

Get in touch

Have a question, a bug report or a feature idea? Email us at service@freeimagecompressor.org or use the contact page.

Ready to try it? Compress an image to 200KB or browse all tools.