What this tool does
Re-encodes your PNG at maximum lossless compression level. No pixels are removed or altered. The output PNG looks identical to the input but occupies less disk space.
Image tool
PNG Compress Online
Compress PNG files to reduce their size without switching formats. PNG compression is lossless — every pixel is preserved exactly. For larger reductions, consider converting to WEBP. All processing runs in your browser — nothing is uploaded.
Complete guide
How to use PNG Compress Online
Image tools guide for png compress online users.
PNG uses a lossless compression algorithm (DEFLATE), so "compressing a PNG" means re-packing the data more efficiently — not discarding pixels. The size reduction from lossless optimization is typically 5–25%, depending on the image content. For bigger reductions, you need to either reduce the colour depth, convert to WEBP, or switch to JPG (for photos).
FormatNest's PNG compressor runs entirely in your browser. It re-encodes the PNG data at maximum compression level. For logos and flat-colour graphics, the reduction can be significant. For photos stored as PNG, the reduction is smaller because the data is already complex and hard to compress further.
If you need to reach a specific file size (e.g., under 200 KB), use Resize Image by KB instead, which adjusts quality until the target size is met.
How to use it
Upload your PNG and click Convert. The compressor applies maximum lossless packing and downloads the result. No settings needed — lossless compression has no quality tradeoff.
Best practices
For logos, icons, and flat-colour graphics: PNG compression is effective. For photographs stored as PNG: convert to WEBP or JPG instead — you'll get 60–80% smaller files. PNG compression alone saves only 5–15% on photos.
Quick checklist
- Confirm the input file, value, text, or measurement is correct before running the tool.
- Use the visible dropdowns and settings to choose the output format, unit, quality, size, or result style.
- Check the preview, result text, or downloaded file before using it for important work.
- For private or sensitive data, prefer browser-based tools and avoid uploading files unless the tool clearly needs server processing.
Answers
PNG Compress Online FAQs
Does compressing a PNG reduce image quality?
No. PNG compression is always lossless — every pixel is stored exactly. The compressed file looks identical to the original at every zoom level.
How much smaller will my PNG be?
Logos and flat-colour graphics: 10–30% smaller. Photos stored as PNG: 5–15% smaller. For larger reductions on photos, convert to WEBP or JPG.
Is this better than using 'Save for Web' in Photoshop?
Comparable. Photoshop's 'Save for Web' also applies maximum PNG compression. You may see small differences (1–5%) in file size depending on the encoder used.
Is my image uploaded to a server?
No. PNG compression runs entirely in your browser. Your image never leaves your device.
Can I compress a PNG with a transparent background?
Yes. Transparency is fully preserved in lossless PNG compression. The alpha channel is not affected.