PNG vs JPG for Online Forms: Which Should You Use?
Photos should be JPG; screenshots, logos and line art can be PNG. But if the form names a format, that settles it.
The short version
| JPG | PNG | |
|---|---|---|
| Compression | Lossy: discards detail to save bytes | Lossless: keeps every pixel |
| Best for | Photographs | Screenshots, logos, line art, text |
| File size of a photo | Small | Much larger |
| Transparency | No (becomes a solid colour) | Yes |
| Quality when re-saved | Loses a little each time | No loss |
For online forms
- Follow the form. If it says JPG or JPEG, give it a real JPG. If it says PNG, give it PNG.
- Photos: JPG. A photo as PNG is typically several times bigger and will blow through a KB limit. See why is my image file so large.
- Signatures: usually JPG. Most forms ask for it. A cleaned signature on white compresses very small as a JPG.
- Screenshots and graphics: it depends. PNG keeps text crisp. But if the form asks for JPG or you have a tight limit, convert.
- Need transparency? Only PNG (or WebP) can keep it. Converting to JPG fills transparent areas with a colour. WillItUpload defaults to white, never black.
What WillItUpload does with each
- Compress Image treats PNG as lossless: only fewer pixels make a PNG smaller. If your PNG is over the limit, save as JPG under Advanced for a bigger saving. If the file is already under the limit, it’s returned untouched.
- Convert to JPG reads PNG, WebP, HEIC, GIF, BMP and AVIF and outputs a real JPG, optionally within a KB limit.
- Convert to PNG keeps every pixel and transparency. Converting a JPG to PNG doesn’t make it sharper, since the detail JPEG discarded isn’t coming back.
JPG vs JPEG
Same format, two spellings of the extension. No conversion is needed between them.
If the site says the format is unsupported, see how to fix an unsupported file format error.