Image Compress — Free online image compressor

Compress JPEG, PNG, WebP, AVIF, and HEIC images right in your browser. Batch processing, quality control, resize, and target file size — all client-side. Files never leave your device.

Features

  • Batch compression — drop multiple files, process them in parallel.
  • Output formats: JPEG, WebP, AVIF, and PNG (with optional palette quantization).
  • Quality slider 1–100 and optional target file size in KB.
  • High-quality Lanczos resize via pica — pick max long side or scale factor (×1.5 to ×16).
  • Before / after comparison slider for every file.
  • Download each file or all of them as a ZIP archive.
  • Built-in presets: Web, Avatar, Thumbnail, Max quality.
  • Light and dark themes with system preference detection.
  • 100% client-side: WebAssembly codecs from the Squoosh project run in Web Workers.

How it works

  1. Drag and drop one or more images into the app, or click to choose files.
  2. Pick a preset, or set the format, quality, resize, and other options manually.
  3. Press Compress. The app decodes each file, optionally resizes it, and re-encodes with WebAssembly codecs in Web Workers.
  4. Preview the before / after comparison and download the result.

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Frequently asked questions

Are my images uploaded to a server?

No. Everything runs in your browser via WebAssembly. There is no upload and no server-side processing.

Which formats are supported?

Input: JPEG, PNG, WebP, AVIF, and HEIC/HEIF. Output: JPEG, WebP, AVIF, and PNG.

What is the difference between WebP and AVIF?

AVIF typically produces 20–40% smaller files than WebP at similar quality, at the cost of slower encoding. WebP is faster and well-supported.

Why did my PNG get bigger after compression?

If the source PNG was already optimized (e.g. via oxipng or zopflipng) and uses a palette, naive re-encoding can grow the file. Try the palette quantization option, or switch to lossy WebP / AVIF for screenshots and graphics.

Does it work offline?

Yes — after the first visit the app and all encoders are cached.

Is EXIF metadata removed?

Yes. Re-encoding always strips EXIF, GPS, and other metadata.