PNG Compressor

How to use this tool

1. Select your file, drag it onto the box above, or paste it from your clipboard.
2. Processing starts automatically — there is nothing to configure.
3. Check the result panel, which shows the original size, the final size and the output dimensions.
4. Click Download to save it.

PNG is lossless, which means it has no quality dial at all — the same pixels always produce the same file. The only way to make a PNG smaller is to reduce its dimensions, which is what this tool does, in steps, until it fits your target.

The specification

Why uploads get rejected

Meeting the size is only part of it. These are the failures that actually come up:

• The image is a photograph saved as PNG. PNG cannot compress photographic detail efficiently, and the JPEG version is often five times smaller at the same visual quality.
• You need both transparency and a very small file. Transparency forces PNG, which limits how far the size can fall.
• The dimensions had to shrink a long way to hit the target — check the result is still usable.

How it works

Most compressors pick a fixed quality level and hope for the best, which is why they either overshoot the limit or land far below it and throw away detail you did not need to lose.

This tool runs a binary search instead. It encodes your image at a mid-range quality, measures the resulting file, then narrows the range — higher if there is room, lower if it is over — repeating seven times. It keeps the largest result that still fits. If the lowest quality is still too big, it reduces the pixel dimensions and searches again.

All of it runs on your own device using the browser's canvas API. Nothing is transmitted.

Who uses this

Logos, icons, screenshots and graphics with transparency, where converting to JPEG is not an option.

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