Does compressing lose quality?

PNG compression is lossless by definition — every pixel survives exactly. Optimising a PNG means improving how efficiently those pixels are encoded: choosing better filter strategies, stripping metadata the image does not need, and reducing the palette where the image genuinely has few colours.

Screenshots, UI graphics, logos and design-tool exports are where this pays. Figma, Sketch and Illustrator all emit PNGs carrying embedded colour profiles and generator metadata, and none of them optimise the compression afterwards. A 2 MB icon set commonly drops below 500 KB with no visible change at all.

If the image is a photograph rather than a graphic, PNG is the wrong format to be optimising. Lossless compression handles continuous-tone detail badly, and converting to WebP will save an order of magnitude more than any amount of PNG optimisation can.

You typically reach for Compress PNG when a PNG file is too large for its destination. Common situations include:

• Email attachments – Gmail caps at 25 MB, Outlook at 20 MB; a single phone photo is often 6–10 MB.
• Upload portals – real-estate listing sites, school portals and insurance forms commonly cap each file at 2–5 MB.
• Web performance – compressing hero images and gallery photos directly improves Core Web Vitals scores and reduces bandwidth costs.
• Storage – when archiving thousands of photos to a cloud drive, a 70–80% size reduction at quality 85 is invisible to the eye.

1. Open the Compress PNG tool on webp.now.
2. Drag your PNG file onto the drop zone, or click Select files. You can drop a whole folder of files at once.
3. Pick a compression preset (Small, Balanced, High, Max) or move the quality slider for fine-grained control. Higher quality = larger file.
4. Click Compress. The job runs on our server and finishes in a few seconds for typical photos.
5. Download the result. Files stay in storage for 24 hours and are then permanently deleted.

The entire flow is free for the first 10 jobs per day with no signup required. A free account doubles that quota; a premium plan removes the limit entirely.

• Strip metadata first — design-tool exports carry colour profiles and generator tags that often outweigh the pixel savings.
• Palette quantisation is the big win on screenshots and UI graphics: most have well under 256 distinct colours.
• Leave the colour profile intact on anything print-bound; stripping it will shift the colours at the press.
• If the PNG is a photograph, convert to WebP instead — PNG optimisation cannot compete on continuous-tone images.
• Run compression as a build step rather than by hand, so newly added assets never slip through unoptimised.