Compress PNG Online
Shrink PNG files by 50–80% with smart palette compression — the same technique TinyPNG uses — right in your browser. Transparency is preserved.
Why compress a PNG?
How PNG compression works
A normal PNG stores 16 million possible colours per pixel. Most images only use a few hundred distinct ones, so we build an optimised palette of up to 256 colours and re-encode the image against it. Dithering smooths gradients so the result is visually identical at a fraction of the size.
When to use it
Screenshots, UI graphics, logos, illustrations and any image with transparency. For photographs, converting to WebP or JPG usually gives even smaller files.
How to compress a PNG
- Upload — drop your PNG file(s) onto the box or click to browse.
- Tune — adjust the palette size and dithering
- Download — each compressed file shows its before/after size and savings.
What we measured
This tool reduces a PNG to a palette of up to 256 colours. We ran four kinds of image through it at the default settings.
| Setting | Result |
|---|---|
| Photos (average of 5) | 599 KB to 187 KB, but visibly banded (quality score 0.87) |
| Website screenshot | 292 KB to 154 KB (score 0.97) |
| Text-heavy page | 234 KB to 117 KB (score 0.999, effectively identical) |
| Bar chart | 21 KB to 15 KB (score 0.999) |
Palette compression suits screenshots, text and charts. For photographs, convert to JPG or WebP instead. Full method and numbers: PNG vs JPG vs WebP, what we measured.
Frequently asked questions
Will I lose quality?
Technically a small amount — the image is reduced to at most 256 colours. For graphics and screenshots the result is indistinguishable; for photos with subtle gradients, keep dithering on and use the full 256-colour palette.
Is transparency kept?
Yes. Fully transparent and semi-transparent pixels both survive compression.
Why is my file not much smaller?
If the PNG was already 8-bit (indexed) or very small, there's little left to squeeze. Try lowering the palette size, or convert to WebP for a bigger win.
Is this tool free?
Yes — every tool on ConvertPicto is completely free, with no account, no watermark and no file limits. The site is supported by ads.
Are my images uploaded to a server?
No. ConvertPicto runs entirely inside your browser using the Canvas API. Your files are read locally, processed on your device and never sent anywhere — we don't even have a server that could receive them.
Does it work on my phone?
Yes. The site is fully responsive and works in any modern mobile browser (Chrome, Safari, Firefox, Edge). Processing large images is naturally slower on a phone than on a laptop.