How to Compress PNG Without Losing Quality (Keep Transparency)
Shrink PNG files while keeping them sharp and transparent, get a PNG under 100 KB, and know when converting to JPG or WebP is the smarter move.
To compress a PNG without visibly losing quality, reduce the number of colours it uses rather than its pixels. The compress PNG tool does this: it rebuilds the image with a palette of up to 256 carefully chosen colours, the same technique TinyPNG made popular, and keeps the transparent background. Screenshots, logos, icons and illustrations often shrink by more than half and look the same. If your PNG is actually a photo, convert it with PNG to JPG or PNG to WebP instead, which saves far more.
The tool runs in your browser, so the image is not uploaded.
Why PNG compression is different from JPG
JPG has a quality slider because it is lossy: it throws away fine detail to save space. PNG is lossless: it stores every pixel exactly, then packs the data as tightly as it can. Re-saving a PNG with a "better" packer usually saves only a little.
The big savings come from changing what is stored. Most PNGs are saved with full 24-bit colour plus transparency, which allows millions of colours even when the image only uses a few hundred. Reducing the image to a 256-colour palette shrinks the file a lot, and for flat graphics nobody can tell.
Strictly, colour reduction is a small loss. For graphics it is invisible; for photos and smooth gradients it can show as slight banding. That is the honest meaning of "without losing quality" for PNG: without losing quality you can see, on the right kind of image.
How to compress a PNG file, step by step
- Open compress PNG.
- Choose one or more PNG files, or paste a screenshot from the clipboard.
- Choose how to compress:
- Quality: higher settings keep more colours (256 at 80% and above, fewer as you go lower).
- Target size: type a KB limit and the tool picks the most colours that fit.
- Check the before and after sizes, then download. For several files, use Download all (.zip).
Transparency is kept in every case.
Compress PNG to 100 KB
To compress a PNG to 100 KB, switch Compress by to Target size and type 100. The tool tries 256 colours first, then 128, 64 and 32. If even 32 colours will not fit, it scales the image down in steps until it does.
Whether that looks good depends on the image:
| PNG type | What happens at 100 KB |
|---|---|
| Logo or icon | Usually far under 100 KB with full detail |
| Screenshot of text or an app | Usually fits; text stays crisp |
| Diagram or illustration | Usually fits with no visible change |
| Large screenshot of a busy web page | May need fewer colours or slight scaling |
| Photo saved as PNG | Often needs scaling; convert to JPG instead |
PNG to JPG to shrink photos
If your PNG is a photo (a camera picture, a scan or a screenshot of a photo), colour reduction is the wrong tool. Photos need smooth colour, and PNG stores them inefficiently.
Converting with PNG to JPG usually cuts a photo PNG to a fraction of its size with no visible change. The catch: JPG has no transparency, so transparent areas turn white. That is fine for a photo, but not for a logo you want to place on a coloured background.
For exam and job forms that ask for JPG, this conversion is often required anyway. If the JPG is still too big, use a target-size tool such as compress image to 100 KB.
PNG to WebP: small and still transparent
PNG to WebP is the best of both for websites. WebP files are typically much smaller than PNG and keep transparency, and every current major browser displays them. The downside is compatibility: many upload forms and older apps do not accept WebP. Use it for your own site, not for portals. The JPG vs PNG vs WebP guide compares all three.
Compress PNG on Mac
Preview on a Mac does not have a PNG compression setting. What you can do:
- Reduce the pixels: Tools, then Adjust Size, enter a smaller width with Scale proportionally ticked, and save.
- Change the format: File, then Export, and pick JPEG (loses transparency) with a quality slider.
To keep the PNG at full size with transparency and still shrink it, use compress PNG in Safari or Chrome on the Mac.
Compress PNG in Windows
Windows Paint and Photos can resize a PNG (fewer pixels means a smaller file) and can save it as JPEG. Neither has a colour-reduction option, so a PNG kept at the same pixel size stays roughly the same file size. For a smaller PNG that keeps its size and transparent background, the browser tool is the simpler choice. More laptop options are in how to compress image size in a laptop.
Tips for smaller PNGs from the start
- Crop empty space. Big transparent or white margins still cost bytes. Use crop image.
- Do not save photos as PNG. Use JPG for photos unless you need transparency.
- Screenshot only what you need. A screenshot of one window is much smaller than a full 4K screen.
- Keep graphics flat. Gradients, shadows and noise textures make PNGs grow quickly.
Common mistakes
- Converting a logo to JPG to save space. You lose the transparent background and get fuzzy edges around text. Compress the PNG instead.
- Using compress PNG on a photo and wondering why it bands. Photos need JPG or WebP.
- Expecting a lossless optimiser to halve the file. Pure lossless re-packing usually saves only a little. Colour reduction is where the real savings are.
- Compressing again and again. Once a PNG is reduced to a palette, compressing again does little except risk more banding. Go back to the original if you need a different result.
Pick the method by the content: graphics stay PNG and get colour reduction, photos become JPG or WebP. That one decision does most of the work.
Questions
How do I compress a PNG file without losing quality?
Use a colour-reduction compressor like compress PNG. It cuts the image to a palette of up to 256 well-chosen colours, which usually looks identical for screenshots, logos and graphics while saving a large share of the file size. Transparency is kept.
How do I compress a PNG to 100 KB?
Open compress PNG, set Compress by to Target size and type 100. The tool reduces colours step by step and, if that is not enough, scales the image down slightly until it fits under 100 KB.
Does compressing a PNG remove the transparent background?
Not with compress PNG, which keeps transparency. Converting to JPG does remove it, because JPG has no transparency; transparent areas become white. Converting to WebP keeps it.
How do I compress a PNG on a Mac or in Windows?
The built-in apps can only make a PNG smaller by reducing its pixel size: Tools then Adjust Size in Mac Preview, or Resize in Windows Paint. To shrink a PNG while keeping its size and transparency, use a browser tool such as compress PNG.
Why is my PNG so large?
PNG is lossless and is designed for flat colours and sharp edges. Photos have millions of slightly different colours, so a photo saved as PNG is often several times larger than the same photo as JPG.