Compress PNG Files Locally in Your Browser
This PNG compressor decodes your image, reduces its palette to 256 colors or fewer, and optimizes the resulting PNG. The pixel dimensions stay unchanged, and output remains a real PNG with transparency support. Palette reduction is lossy: colors and partially transparent edges can change. Compare the output with the original, especially on gradients and small text. If compression would make the file larger, the original may be returned instead.
Everything happens in your browser through WebAssembly. When you use this online png compressor your files are processed entirely on your own device and are never uploaded to a server — it is faster (no upload wait), private, and free with no sign-up and no watermark.
Lossy vs Lossless PNG Compression
PNG files use lossless encoding, but a compressor can alter pixels before encoding. This page uses palette quantization followed by PNG optimization; it currently has no lossless-only switch.
- •Lossy palette quantization reduces the number of colors. It can work well for icons and flat graphics, but inspect the result for color shifts or banding. This is the mode used on this page.
- •Lossless optimization avoids deliberate palette reduction. The optimization pass after quantization cannot restore colors already removed. If exact pixels matter, keep your original and use a separate lossless-only workflow.
Why PNG Files Get So Big
PNG can store detailed pixels, text and transparency, which is useful for logos, screenshots and cutouts. Photographs and smooth gradients can produce large PNG files. Reducing the palette may save space but can change visible colors. For photographs without transparency, compare JPG or WebP output from an image converter; there is no format that is smallest for every image.
When to Use a PNG Compressor (and When to Convert)
- •Logos, icons and UI assets — compress as PNG to keep crisp edges and transparency
- •Screenshots with text and flat-color illustrations — quantization shrinks these the most
- •Transparent graphics for web, apps and e-commerce — PNG keeps the alpha channel
- •Photographs or detailed gradients without transparency — compare a JPG or WebP conversion; the best format depends on the image.
Tips to Compress PNG Without Losing Quality
- •Resize to the dimensions you actually display first — a 3000px logo shown at 300px wastes most of the file.
- •If quantization causes banding or changes an edge, keep the original or use a separate lossless-only optimizer.
- •Compress once from the original export rather than re-compressing an already-processed file.
- •Compressing a whole icon set? Use batch mode and download everything as a single ZIP.
PNG Compressor — Frequently Asked Questions
What is a lossy PNG compressor?
A lossy PNG compressor reduces the image’s color palette before saving another PNG. This page uses up to 256 colors followed by PNG optimization. File-size savings depend on the source. Compare the output with your original: colors, gradients and semi-transparent edges can change.
Can this PNG compressor convert a PNG to JPG?
No. This page keeps the output as PNG. For a photo without transparency, try our image converter to compare JPG or WebP. JPG does not support transparency. Download the file before changing tools, then upload it on the next page; files are not transferred automatically.
Is PNG compression lossless?
PNG encoding is lossless, but reducing colors before encoding changes pixels. This page uses lossy palette quantization followed by optimization and currently has no lossless-only switch. The optimization step cannot undo the palette changes. Keep the original if exact pixels are required.
Does compressing a PNG keep transparency?
The output remains PNG with transparency support. Palette quantization can change partially transparent pixels and edge colors, so inspect the result on both light and dark backgrounds. Retain the original if those details are important.
Are my images uploaded to a server?
No. Compression runs locally in your browser. Image files are not uploaded for processing, and no account or payment is required.
Can I compress several PNG files at once?
Yes. Add several PNGs, start compression and download the results individually or together in a ZIP. Each file is processed separately, so the amount saved can differ. Already optimized PNGs may be returned unchanged.
How do I compress a PNG to an exact size like 100KB?
For a file-size limit, try the 100KB compressor, 50KB compressor or 200KB compressor. These tools aim for an upper limit, not an exact byte count, and a PNG may remain above the target. Download your image before switching tools, upload it again, and check the actual size and transparency before submitting it.