What each format is for
- **JPEG (.jpg / .jpeg)** — lossy, no transparency, almost universally accepted. The default for photographs anywhere a byte limit or an upload form is involved. Quality is a dial you choose when saving.
- **PNG (.png)** — lossless, supports full transparency, larger files. The right choice for logos, line art, screenshots with text, scans of documents, and anything that must keep a transparent background. A photograph saved as PNG is usually many times larger than the same photo as JPEG.
- **WebP (.webp)** — modern, lossy or lossless, supports transparency, typically smaller than both for the same visual quality. Browsers and most current sites handle it well, but some older upload portals, desktop applications and print shops do not accept it.
Choosing by situation
- **Online application form** — usually JPEG. It is the format almost every portal lists explicitly, and it is the easiest to keep inside a KB range. Use Image Converter if your file is currently PNG or WebP.
- **Signature or logo that must sit on any background** — PNG, with the background removed using Transparent Background. JPEG cannot store transparency; it will fill the cut-out with a solid colour.
- **Screenshot or scanned document with text** — PNG, because lossless encoding keeps text edges crisp. If the scan must fit a byte limit, PNG may be too large; JPEG at quality 85–90 is the usual compromise.
- **Photograph for print** — JPEG at the highest quality you can afford, at the dimensions the print size actually needs. See DPI and the printing guides for how many pixels a page needs.
- **Website or listing image where the platform allows it** — WebP for the smallest transfer; keep a JPEG or PNG copy for anything that must be portable.
Converting without losing more than intended
- Open Image Converter and add the files — it batches, so a whole folder can be handled in one run.
- Pick the target format. For photographs choose JPEG and set quality around 85 as a starting point; for graphics choose PNG and leave quality alone.
- For images with transparency, keep PNG. Converting to JPEG will flatten the background and the cut-out will be lost.
- Convert, then check one result with Image Metadata to confirm the format and size are what you expected.
Conversion is one-directional in quality terms. A JPEG converted to PNG does not regain the detail JPEG already discarded — it just stores the already-lossy pixels losslessly, in a much bigger file.
When a form rejects the format
Upload forms commonly list JPEG and PNG and nothing else. If you are handed back an error mentioning the file type, convert before adjusting anything else — re-compressing a WebP that the form will not accept wastes time. See Common reasons online forms reject uploaded images for the other frequent causes.
Common questions
Which format gives the smallest file?
For photographs at the same visual quality, WebP is usually smallest, then JPEG. For graphics with flat colour or transparency, PNG is often the most sensible despite being lossless, because it handles hard edges cleanly.
Can I convert PNG to JPEG without any loss?
No — JPEG is lossy, so some detail is discarded. In practice, for a photograph the difference is rarely visible at quality 85–90; for text or line art it can be, which is why PNG is preferred there.
Do all browsers open WebP?
Current browsers do. Older desktop software, some email clients and many upload portals do not. When the destination matters more than the file size, JPEG is the safe choice.