Convert JPG and PNG
Turn an image from JPG into PNG, or the other way round
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JPG or PNG image · Up to 100 MB
How do you convert JPG to PNG, or PNG to JPG?
You upload the image, pick the format you want, and the tool rewrites it in that format. The dimensions do not change. The two formats are not equivalent: PNG keeps transparency and is lossless, while JPG gives a far smaller file for photographs.
What this tool does not do
- It does not change the image dimensions — the Compress an image tool is for that.
- It does not keep transparency when converting to JPG: transparent areas are filled white.
- It does not restore quality already lost in a JPG — converting to PNG makes the file bigger, not better.
Example: a logo with a transparent background
An 800×800 PNG logo with a transparent background came to 96 KB. Converted to JPG it dropped to 41 KB, but the transparent background became a white square — on a dark presentation slide that is obvious immediately. The other way round: a 2.1 MB JPG photograph became 8.4 MB as a PNG, because PNG is lossless and faithfully preserves even the small artefacts the JPG already contained.
When a journal demands a particular format
Journals often require a specific format for illustrations: PNG for diagrams and charts, JPG for photographs. The requirement is not arbitrary — the sharp lines of a diagram blur in JPG, and a photograph in PNG produces an unreasonably large file. Choosing the wrong one can get a paper returned on a technical ground. Keep the original before converting: a conversion to JPG cannot be undone. Changing the format does not change the pixel count: when a journal asks for 300 dpi it is asking about the image's dimensions, not its file type — a low-resolution photo does not get sharper by becoming a PNG. Converting PNG to JPG replaces a transparent background with white.
| Accepts | JPG or PNG image |
|---|---|
| Returns | Several files — in a ZIP archive |
| Maximum file size | up to 100 MB |
| Several files at once | Yes |
| Is the file uploaded | No — everything runs in your browser |
| Price | Free |
| Account needed? | To download — yes (free) |
Frequently asked questions
Which format should I choose?
PNG for diagrams, charts, screenshots of tables and anything with a transparent background. JPG for photographs and scanned pages, where it gives a far smaller file.
Does converting to PNG improve quality?
No. PNG preserves the pixels you have without further loss, but it cannot bring back detail already lost in a JPG — the file simply gets bigger.
What happens to transparency?
Converting to PNG keeps it. Converting to JPG loses it and fills those areas with white — JPG has no transparency at all.
Can I convert several images at once?
Yes. Several images come back as one ZIP.