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Compress PNG Images Online

Optimise still PNG graphics without silently switching formats. Keep transparency and try lossless compression before considering smaller dimensions.

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Make room for smaller images

No uploads to servers

Drop your images here

or select files from your device

PNG · Up to 20 images · 15 MB each · 60 MB per batch
Still images only. Maximum 8 megapixels and 8192px per side.

Your images are processed directly in your browser and are not uploaded to our servers.

Compression settings

Formats are never changed silently. Unsupported browser encoders show an error.

A maximum size to attempt, not an exact-size guarantee.

PNG uses lossless scanline recompression, not a quality slider.

Pixels. Images are never enlarged. Resizing changes image detail, including for PNG.

0 / 20 images · 0.0 KB

Files stay in this tab until you clear them or leave. Re-encoded JPG/WebP and resized images may lose metadata and change colour rendering. Lossless PNG keeps colour and orientation chunks; original fallbacks retain their metadata. Always check the downloaded image before sharing it.

How to use PNG Compressor

  1. Select or drop PNG images into the tool. File content is checked before processing.
  2. Keep the original dimensions for lossless PNG optimisation, or choose optional resizing.
  3. Press Compress images. Each file is processed in a background worker.
  4. Review the actual sizes, dimensions and comparison previews. Open the download to inspect full detail.
  5. Download each result or prepare a ZIP of completed images. Keep your originals until you are satisfied.

PNG-specific lossless optimisation

At unchanged dimensions, this tool validates PNG chunks and recompresses the image scanlines with DEFLATE. It retains image samples, bit depth, palettes and transparency rather than applying a JPEG-style quality setting. Textual metadata and timestamps are removed from optimised files; colour and orientation chunks are retained. Original fallbacks are unchanged.

Transparent graphics and optional resizing

PNG output keeps its alpha channel. The checkerboard in the preview helps you inspect transparent areas. Resizing is optional and preserves the aspect ratio, but resampling changes pixels and can soften text or fine lines. Resized PNGs use browser-rendered colour and 8-bit pixels; use unchanged dimensions when preserving original samples matters.

When a PNG will not get smaller

PNG is often already well compressed. Recompressing a photograph stored as PNG may save very little. This version does not offer lossy palette quantisation. If the result is not smaller, download the original. For a strict byte limit, explicitly allow smaller dimensions or use the main compressor to select WebP; no conversion happens silently.

Frequently Asked Questions

Does PNG compression preserve transparency?

Yes. Unchanged-size optimisation preserves the original alpha information, and resized PNG output retains an alpha channel.

Why is there no PNG quality slider?

Browser canvas quality does not control PNG compression. This tool uses a separate PNG recompression path. It does not implement lossy colour quantisation.

Are animated PNGs supported?

No. Animated PNG files are rejected with an explanation so you do not accidentally lose animation.