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Image Tools

Compress PNG Images — Free

Reduce PNG file size using smart compression. Maintains transparency.

Lossless compressionPreserve transparencyBatch processingSignificant reduction
或从以下导入

200万+文件已转换

数千用户的信赖之选

安全传输

HTTPS 加密上传

隐私优先

文件处理后自动删除

无需注册

即刻开始转换

随处可用

任何浏览器，任何设备

如何转换

1

Upload your PNG images.

2

Choose compression level.

3

Download optimized PNGs.

About PNG Compressor

PNG compression reduces file sizes of graphics, screenshots, and images with transparency while maintaining the format's key advantages: lossless quality and alpha channel support. Our optimizer can reduce PNG files by 50-80% depending on image content and complexity.

PNG compression uses two approaches. Lossless compression reorganizes image data for more efficient storage without any quality reduction—perfect for images that will be edited further. Lossy compression (color quantization) reduces the color palette while maintaining visual appearance, achieving dramatic size reductions with minimal perceptible difference.

UI/UX designers compress interface graphics for faster app loading. Web developers optimize icons, logos, and graphics with transparency. Game developers compress sprite sheets and texture atlases. Documentation writers compress screenshots for smaller file sizes. Brand managers optimize logo files for web use while maintaining transparency.

Our PNG optimizer analyzes each image to determine the optimal compression strategy. Images with few colors benefit most from palette reduction. Images with smooth gradients use dithering algorithms that preserve visual smoothness. All compression preserves PNG's transparency capabilities, keeping alpha channels intact for seamless web integration.

Common Use Cases

  • •Optimize logos and graphics with transparency
  • •Compress screenshots for documentation
  • •Reduce icon sizes for faster web loading
  • •Optimize game sprites and UI elements
  • •Compress graphic design assets for delivery

How It Works

Our PNG compressor uses pngquant for color quantization with Floyd-Steinberg dithering, followed by optipng for additional lossless optimization. The process preserves alpha channels and supports both indexed and truecolor output.

Supported Formats

.PNG

常见问题

Yes, PNG transparency (alpha channel) is fully preserved during compression.
Lossless preserves exact pixels but offers less compression. Lossy reduces colors for smaller files with minimal visual difference.
Simple graphics with flat colors compress 60-80%. Complex images with many colors compress 30-50%. Screenshots typically compress 40-60%. Lossy (color quantization) achieves greater reduction than lossless optimization.
Indexed-color PNGs (already using a limited palette) benefit less from color quantization. Our optimizer still applies lossless compression techniques like DEFLATE optimization, which can reduce these files by 10-20%.
WebP produces 25-35% smaller files than optimized PNG with equivalent quality. However, PNG has 100% browser support while WebP lacks support in some older browsers. Use PNG when maximum compatibility is critical; use WebP when file size is the priority.
Yes. PNGs with text and sharp edges actually compress very well because color quantization works best with limited color palettes. Text remains crisp and readable after compression.
Yes. 16-bit PNGs are supported, though they are automatically reduced to 8-bit during lossy compression (which is where the biggest size savings come from). For lossless mode, 16-bit depth is preserved.