Compress Image

Reduce JPG, PNG and WebP file sizes in your browser. Batch supported, no upload, no quality compromise you didn't ask for.

Image compression shrinks file size by re-encoding photos with smarter quality and resolution settings. Converterzilla's image compressor uses the open-source browser-image-compression library inside a Web Worker, so the heavy lifting happens in your tab without freezing the UI. Files are read from your disk, processed in your browser, and saved back — never uploaded.

How to use Compress Image in your browser

  1. Drop your images. Drag JPG, PNG or WebP files onto the upload area. Add as many as you want — batch compression is supported.
  2. Set the target size and dimensions. Slide the target file-size slider to the maximum size each image should be (default 1 MB). Cap the longest edge if you also want a smaller resolution.
  3. Click Compress. Each image runs through the compressor in a Web Worker. The UI stays responsive even with large batches.
  4. Download the results. Click Download to save the compressed images. The summary shows total bytes saved across the batch.

Why use Converterzilla for Compress Image

Web-Worker compression

We process images in a Worker so the page stays responsive — drag in 50 images and the UI doesn't freeze.

Smart target sizing

Tell us the max size per file, we figure out the right quality and resolution. No fiddling with technical knobs unless you want to.

Privacy-first by default

Files are never uploaded — they're read locally with the browser's File API and compressed in your tab.

Preserves transparency

PNGs with transparency stay transparent; WebPs keep their alpha channel. JPG output gets a white background fill where needed.

Frequently asked questions about Compress Image

Photos shot on a modern phone (4-8 MB JPG) usually compress to 200-500 KB at our default settings with no visible difference at normal viewing distance. PNGs depend more on their content — screenshots compress less than photos.

Slightly — image compression is lossy by definition. We default to a balance that's effectively invisible at normal viewing distance. If you need pixel-perfect output for print, set the target size higher and use PNG.

Yes. Compress as many images as you want, as often as you want. No signup, no daily quota, no watermark on the output.

Resize changes dimensions (e.g., 4000×3000 → 1280×960). Compress changes file size by re-encoding (e.g., 5 MB JPG → 500 KB JPG at the same dimensions). For maximum file-size reduction, use both: resize first, then compress.

Further reading and references

Related browser-based tools

Resize Image

Change dimensions to reduce file size further.

JPG ↔ PNG

Convert between formats — sometimes WebP gives you smaller files.

Compress PDF

The PDF equivalent of this tool.

Watermark Image

Add a watermark before compressing for sharing.