Compress PNG Online
Shrink PNG files by up to 80% using pngquant lossy colour quantisation — the same algorithm behind TinyPNG. Runs entirely inside your browser. Nothing uploaded.
Drop your PNG files here
PNG files only · up to 50 MB each · transparency preserved
Why is PNG so large — and how do you make it smaller?
PNG uses lossless compression, meaning every pixel is preserved exactly. This is great for quality but results in much larger files than JPEG or WebP for photographic content. A 4000 × 3000 px photo saved as PNG can easily be 8–15 MB versus 1–3 MB as JPEG at equivalent quality.
The standard way to compress a PNG without converting it is colour quantisation — reducing unique colours from 16.7 million (24-bit) down to 256 (8-bit indexed). For logos, icons, screenshots, and flat-colour graphics, this reduction is nearly invisible to the human eye.
When to compress PNG vs. convert to JPEG or WebP
- Compress the PNG when your image has transparency, is a logo, icon, illustration, or screenshot, or when you specifically need PNG format.
- Convert to JPEG when the image is a photograph with no transparency and file size matters most — JPEG achieves far smaller files than PNG compression for photos.
- Convert to WebP when the image is for a website — WebP outperforms both PNG and JPEG in most cases while supporting transparency.
How our PNG compressor works
This tool runs pngquant as a WebAssembly module directly in your browser — the same open-source algorithm used by TinyPNG, Squoosh, and professional image optimisation pipelines. It uses a modified median-cut algorithm to find the optimal 256-colour palette for each image, minimising visible quality loss. The entire process is local — no PNG data is ever sent to any server.
Common use cases for PNG compression
- Website performance. Large PNGs slow page load times and hurt Core Web Vitals scores. Compressing them reduces bytes the browser must download.
- App and game development. Sprite sheets, UI assets, and texture atlases must be as small as possible to minimise bundle size and load times.
- Email logos and signatures. Large embedded PNGs can cause emails to load slowly or trigger spam filters. A compressed PNG logo under 100 KB loads instantly.
- Docs and presentations. Screenshots and diagram exports saved as PNG are often oversized. Compressing before embedding in PDFs or slide decks reduces the document file size significantly.
Frequently asked questions
How does PNG compression work?
This tool uses pngquant, the industry-standard lossy PNG compression algorithm. It reduces the number of colours in the image from 16.7 million (24-bit) to 256 (8-bit) using a technique called quantisation. The result is a smaller file that looks nearly identical to the original at normal viewing sizes.
Will lossy compression ruin my PNG?
At quality settings above 70, the visual difference between the original and the compressed PNG is virtually imperceptible on screen. At lower settings, you may notice slight banding in gradients or flat colour areas. The quality slider lets you find the right balance for your use case.
Should I compress PNG or convert to JPEG?
If your image has transparency or is a logo/icon with flat colours, compress the PNG. If your image is a photograph without transparency, converting to JPEG or WebP will give you a much smaller file than any PNG compressor can achieve.
Is my PNG uploaded to a server?
No. The pngquant compression runs in your browser as a WebAssembly module. Your PNG file never leaves your device — not even temporarily.