Compress PNG
Drop a PNG below, pick a compression level and click Compress to reduce its file size. Transparency is preserved at every level. You'll see the before and after size plus the percentage reduction. Everything happens locally in your browser — your image never leaves your device.
Read the guide: How to compress PNG imagesInput
64 colours/channel
Output
Processed locally in your browser — nothing is uploaded.
How the Compress PNG works
- Your PNG is loaded into an in-browser canvas — nothing is uploaded.
- For lossy levels, the RGB colour depth is reduced (alpha is left untouched so transparency is preserved).
- The canvas is re-encoded as PNG, which packs the fewer unique colours more tightly via DEFLATE.
- The new file size is compared with the original so you can see the reduction before downloading.
Useful tips
- Use Lossless for a safe re-encode with no quality change, then try High if you need a smaller file.
- Graphics with few colours (icons, logos) compress far more than detailed photographs.
Frequently asked questions
Is my image sent to a server?+
No. All compression happens entirely in your browser using a canvas. Nothing is uploaded or stored.
How is PNG compression different from JPG?+
PNG has no quality setting — it's lossless. To shrink a PNG we reduce the number of unique colours (which lets PNG's internal compression pack the data more tightly) or simply re-encode it. The alpha channel is left untouched so transparency is preserved.
Which level should I choose?+
Start with High. It keeps most of the visual quality while noticeably reducing the file. Use Lossless when you can't accept any quality change, and Low for simple graphics with few colours where the smallest size matters most.
Will transparency be preserved?+
Yes. The compression only reduces colour depth on the RGB channels — the alpha channel that controls transparency is never modified, so transparent areas stay transparent.
Related guides
How to compress JPG images
Large JPG files slow down websites and fill up storage. This guide explains how JPG compression works, how the quality setting trades size for sharpness, and how to pick a sensible level for photos and graphics — all using a free tool that runs entirely in your browser.
How to compress WebP images
WebP produces smaller files than JPG and PNG while supporting transparency, but it can still be trimmed further by re-encoding at a lower quality. This guide explains how WebP compression works, how the quality setting trades size for sharpness, and how to pick a sensible level — all using a free tool that runs entirely in your browser.
How to reduce image file size to a target
Sometimes you need an image under a specific size — for an upload limit, an email attachment or a web budget. This guide explains how target-size optimisation balances quality and dimensions to hit a file-size limit, and how to reduce an image to 100 KB, 500 KB, 1 MB or 2 MB — all using a free tool that runs entirely in your browser.
How to upscale an image
Sometimes you need an image bigger — for a large hero banner, a print layout or a higher-resolution thumbnail. This guide explains how browser-based upscaling works, how the scale factor and output quality trade sharpness for file size, and how to enlarge an image by 2×, 3× or 4× — all using a free tool that runs entirely in your browser.
