Which format should you pick?
The three output formats are built for different jobs. This table compares them on the points that decide most conversions.
| PNG | JPEG | WebP | |
|---|---|---|---|
| Transparency | Yes | No (filled with white) | Yes |
| Compression | Lossless | Lossy | Lossy or lossless |
| Best for | Logos, screenshots, line art, images you will edit again | Photographs and shared images | Web images, photos or graphics |
| Compatibility | Universal | Universal | Modern browsers; some older software and upload forms reject it |
| Quality setting here | None needed | Fixed at 92% | Browser default |
A quick rule: photographs going to email, print or an unknown upload form suit JPEG; anything with transparency or sharp edges suits PNG; web pages you control can use WebP. The PNG vs JPG vs WebP guide goes into more detail.
What you lose in a conversion
- Transparency
- Lost when going to JPEG; the background becomes white.
- Animation
- Lost for GIF input; only one still frame is kept.
- Metadata
- Camera EXIF and embedded profiles are not carried over.
- Image detail
- Lossy output (JPEG, WebP) discards some detail. Converting back to PNG does not restore it.
The direction matters. Going from a lossless format to a lossy one saves space at the cost of some detail. Going the other way saves nothing: a JPEG saved as PNG keeps every flaw the JPEG had and usually becomes larger. If you will edit an image again, keep a lossless copy and make JPEG or WebP versions from it.
How the conversion works
The image is decoded by your browser, drawn onto a canvas at its original width and height, and saved again in the format you chose. For JPEG output the canvas is first filled with white, so transparent pixels become white rather than black. JPEG is saved at 92% quality, and WebP uses the browser's default quality. PNG is lossless.
The file picker accepts anything the browser reports as an image, up to 20 MB each and 50 per batch. Because decoding is done by the browser, support varies. Formats such as HEIC from an iPhone are not opened by every browser; if yours refuses the file, use the HEIC to JPG tool.
Each output keeps the source file name with the extension swapped, so photo.png becomes photo.jpg. Batches run one image at a time and come back as a ZIP. When a result is ready, the Continue with bar hands it to another tool, such as the resizer or compressor, without re-uploading. Nothing is sent to a server.