Format Convert
Batch-convert image formats online between PNG, JPG, WebP, BMP and more, with adjustable compression quality, max-size limits, and background color for transparent images, plus one-click zip download. Everything runs locally in your browser with no uploads — secure and fast.
1Upload images (batch supported)
Features
- Convert between common formats such as PNG / JPG / WebP / BMP
- Batch-import multiple images, convert in one click and download as ZIP
- Adjustable JPG / WebP compression quality to balance size and quality
- Optional proportional resize to limit the max width/height of output
- Custom background color to fill transparent areas when converting to JPG
- Shows before/after size comparison in real time, fully local with no uploads
FAQ
Are my images uploaded to a server?
No. Image decoding, format conversion, resizing and packaging all happen locally in your browser — files are never uploaded to any server.
Why does the transparent background turn solid after converting to JPG?
JPG does not support an alpha channel, so the tool fills originally transparent areas with your chosen background color. To keep transparency, choose PNG or WebP.
Can I convert multiple images at once?
Yes. Select or drop multiple images at once, set the target format, click "Convert all", then export them together via "Download ZIP".