2026 guide
Is lossy PNG compression cheating?
Honest answer: it depends on what you optimize for, and both camps are right about their own use case. Lossy PNG recompressors (like pngquant-style quantization) shrink files 60–70% by reducing colors and dithering the difference. For photos and gradients, the result is often visually identical; for line art and UI assets with exact brand colors, it can visibly shift flat fills. Pick per file, and always keep the original.
The re-encode camp
"Bandwidth is real money and attention: a 70% smaller file loads faster, converts better on mobile, and the quality difference is below the threshold of perception for photographic content." Tools like quantization + dithering are standard practice in game dev and web delivery, and dithering is an art form in its own right.
The preservation camp
"PNG means lossless. The moment you throw away color information to save bytes, you've made a lossy file wearing a PNG extension — and someone downstream will notice when a brand color is off by 3% or a gradient bands." For assets of record — logos, medical imaging, archival scans — lossy recompression is data destruction, full stop.
A practical decision rule
- Photos, screenshots, textures: lossy recompression is usually invisible — take the 60–70% saving
- Logos, icons, flat brand colors: stay lossless; if size forces the issue, quantize to a tight palette and compare pixel-diffs
- Files of record (medical, legal, archival): never lossy; size is someone else's problem
What our converter does
The PNG converter on this site defaults to honest labeling: whatever mode you pick, the result's format and quality settings are shown before download. No "lossless" claim on a lossy file.
FAQ
Is a quantized PNG still a valid PNG?
Yes — quantization produces a legitimate palette-based PNG, decodable by everything since the 90s. The debate is about data loss, not file validity.
How much smaller is lossy PNG, really?
Typically 60–70% on photographic content (e.g. 800KB → 250KB), less on content that's already flat-colored. JPEG still wins on photos at aggressive sizes, but loses transparency.
Should I keep the original?
Yes, always. Lossy recompression is a delivery step, not a storage step. Archive the lossless source, ship the optimized copy.
Last updated: · Launch guide: both camps + decision rule · change history