Image Compressor / Converter

Compress images locally: adjust quality, resize, convert between JPG/WebP/PNG, compare sizes and download.

What this tool does

Shrinks images: adjust output quality, cap the width, convert formats (JPG / WebP / PNG), see the before/after sizes and a preview, then download. Everything happens locally in your browser — ID photos from your phone and unpublished design drafts never touch a server. Transparent areas are flattened onto white for JPG/WebP output, so a transparent PNG does not turn black when converted to JPG.

Choosing parameters

Photos: JPG at quality 75 is the sweet spot — visually indistinguishable for most purposes, typically 60–80% smaller. For the smallest files use WebP, which beats JPG by another 25–35% at the same quality. Screenshots, line art with text, and images needing transparency: choose PNG (lossless, but huge for photos). A width of 1920px is plenty for the web; phone shots often exceed 4000px, and resizing beats quality cuts — halving dimensions quarters the pixel count.

Caveats

If the output comes out larger than the input, the original was already heavily compressed (e.g. a chat-app-transferred image); only lower quality or WebP will help then. PNG is lossless — the quality slider does not apply; shrinking a PNG requires resizing or switching to a lossy format. Repeated lossy compression accumulates generation loss, so keep your originals. Animated GIFs keep only their first frame after conversion.