JPG, WebP or PNG: which format should you upload?
The accepted format comes before the smallest file. A small WebP will not solve an upload form that accepts only JPG. When several formats are allowed, compare real outputs and consider whether image detail or transparency matters.
A comparison using the same photo and dimensions
We used one JPG sample, a 200 KB target and a 1,600 × 1,600 px bounding box. The resulting proportions were 1,600 × 900 px. Additional dimension reduction was disabled for PNG and WebP. It was not needed in the JPG test either, so all three outputs have the same dimensions.
This is not a matched-quality benchmark. It records the output sizes produced by this tool. Different image content or browser encoders can change the results. One photo does not establish which format is always better.
Measured output sizes
2026-10-03 · Chromium 149.0.7827.55 · One sample photo tested
| Format | Actual bytes | px | Status |
|---|---|---|---|
| JPEG | 197,720 | 1600 × 900 | Met |
| WEBP | 183,814 | 1600 × 900 | Met |
| PNG | 2,738,015 | 1600 × 900 | Over |
These measurements describe one photo in one browser. Different photos or browsers can produce different sizes and quality.
Raw measurement data (JSON)Why PNG can stay above the target
Converting a photo to PNG can make the file larger. This tool does not apply a JPG-style lossy quality adjustment to PNG output. With further dimension reduction disabled, our PNG exceeded 200 KB and the tool correctly marked it as over target.
A transparent logo or a simple graphic can behave differently from a photograph. PNG should not be ruled out for every image because of one large photo result. Test the image you actually plan to use.
Check transparency and the real file format
JPG output replaces transparent areas with white. Check PNG or WebP output when transparency must remain, and make sure the destination supports it. Renaming a file to .jpg is not format conversion.
For a regular photo in a JPG-only form, choose JPG. If transparency matters and the recipient allows it, compare PNG and WebP. Decide from the downloaded appearance and measured size. Keep the original and verify the destination’s requirements in every case.