Compress PNG Images Online — Free & Private

Reduce PNG file sizes using oxipng lossless optimization directly in your browser. Complete privacy — no uploads, no server processing. Batch compress multiple files, adjust optimization level, and optionally convert to WebP for even smaller sizes.

Drag & drop PNG files here or

Supports .png files

80%
Convert to WebP

Compressing...

Compressed Images

Compress PNG Images Without Any Quality Loss

This free PNG compressor uses oxipng, a powerful lossless optimizer that reduces PNG file sizes by 10–30% without changing a single pixel. It works by optimizing deflate compression, trying multiple filter strategies, and stripping unnecessary metadata.

How to Compress PNG Files

  1. Drag and drop your PNG files onto the upload area, or click to browse.
  2. Adjust the optimization level with the quality slider.
  3. For maximum compression, enable Convert to WebP — WebP files are typically 50–70% smaller than PNG.
  4. Click Compress PNG and download your optimized files.

100% Private — Your Images Never Leave Your Device

All processing happens in your browser using WebAssembly technology. No files are uploaded, stored, or accessed by any server. Your images stay on your device at all times.

When to Use PNG vs WebP

PNG is essential when you need lossless quality and transparency — logos, icons, screenshots, and UI graphics. If your target platform supports WebP (all modern browsers do), enable the WebP toggle for dramatically smaller files. For photographs without transparency, our JPEG compressor will produce smaller files.

FAQ

Frequently Asked Questions

This tool uses oxipng, a powerful PNG optimizer compiled to WebAssembly, running entirely in your browser. It performs lossless optimization — removing unnecessary metadata, optimizing deflate compression, and trying multiple filter strategies to find the smallest representation without any quality loss. Your compressed PNG is pixel-identical to the original, just smaller.

No. All compression happens locally on your device using WebAssembly technology. Your PNG files are never transmitted, uploaded, stored, or accessed by any server. This means your images stay completely private, the tool works offline after the initial page load, and there are no file size restrictions from server limits.

There is no enforced file size limit since all processing happens in your browser. However, very large PNG files (20MB+ or high-resolution images with many colors) require more memory and processing time. Most PNGs compress quickly. If you experience slowdowns with very large files, close other browser tabs to free up memory or compress in smaller batches.

With lossless optimization, typical PNG files are reduced by 10-30% depending on how well-optimized the original was. Unoptimized PNGs (from screenshots, design tools) often see the largest gains. For greater reduction, use the "Convert to WebP" toggle — WebP typically achieves 50-70% smaller files than PNG. The exact savings depend on image content and how the original was saved.

Yes. PNG transparency (alpha channel) is fully preserved during compression. Since oxipng performs lossless optimization, your transparent backgrounds, semi-transparent overlays, and alpha channels remain pixel-perfect in the compressed output. This makes it ideal for compressing logos, icons, UI elements, and any graphics that use transparency.