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SlimMyFile

Compress PNG images

Shrink PNG screenshots, logos and graphics while keeping transparency. Choose pixel-perfect lossless optimisation or much smaller colour-reduced files.

Processing happens in your browser. Files are never uploaded to a server.

Drop files here

or

JPG, PNG, WebP · up to 50 MB each

Files are opened locally and never uploaded.

How to use this tool

  1. 1Add PNG images (JPG and WebP are accepted too).
  2. 2Choose Reduce colours and a colour count, or Lossless.
  3. 3Compress and inspect edges against the checkerboard preview.
  4. 4Download the optimised PNG files.

Supported formats

Input
PNG, JPG, WebP
Output
PNG by default

Features

  • Lossless optimisation with OxiPNG
  • Colour reduction to 16–256 colours, with dithering
  • Transparency preserved in both modes
  • Exact, lossless re-optimisation of the original file when you do not resize

Two honest ways to compress PNG

PNG is a lossless format, so a JPEG-style quality slider would be misleading. SlimMyFile offers two clearly different modes instead:

  • Lossless: OxiPNG rewrites the file with better filters, compression and bit depth. Every pixel stays identical.
  • Reduce colours: an optimised palette of up to 256 colours is built for your image (similar to pngquant), then saved losslessly. For logos and graphics this is often far smaller than lossless mode, with little visible change.

Transparency is preserved

Both PNG modes keep the alpha channel. If you convert to WebP, transparency is kept too. Only JPEG output requires filling transparent areas with a background colour, which you can choose.

When to convert PNG to another format

Photos saved as PNG are often very large. Converting them to WebP or JPEG can reduce their size dramatically. Screenshots with text usually look best as PNG or high-quality WebP.

Your privacy

Files are read and processed by your browser on this device. They are not uploaded, stored or shared, and closing the page discards them. Processing speed and the largest file you can handle depend on your device.

Frequently asked questions

Why is lossless PNG compression sometimes small?

If the PNG was already saved by a good encoder, there is little redundancy left. Colour reduction or converting to WebP gives much larger savings.

Does colour reduction work for photos?

It works, but photos have many subtle colours and may show banding. For photos, WebP or JPEG output is usually the better choice.