PNGをWebPに変換 — 無料

The quality slider runs from 20 to 100 and defaults to 90. For UI icons and screenshots, 80-90 keeps text and edges crisp; for photographic PNGs, dropping to 70-80 usually shrinks the file noticeably further with barely visible loss.

Turning on Lossless mode disables the quality slider and re-encodes with every pixel preserved exactly — the right choice for logos, flat-color graphics and screenshots with sharp text where any compression artifact would be visible. It still typically beats the original PNG's size even though it's larger than the lossy quality-controlled output.

For flat-color icons, logos and screenshots with text, switch Lossless mode on so edges stay perfectly sharp with no banding. For photographic PNGs, leave Lossless off and set the quality slider to 75-85 — you'll get a much smaller file with a difference that's hard to spot at normal viewing sizes.

Yes. WebP supports a full alpha channel just like PNG, so every transparent pixel is preserved exactly regardless of the quality or lossless settings you choose — nothing gets flattened to a solid color.

Yes. Switch to Batch mode, add all your PNGs, and they're converted with the same quality/lossless settings and delivered as one ZIP. Batch conversion is a Premium feature; single PNG-to-WebP conversions are always free with no watermark.