JPEG to PNG — Troubleshooting

Worked example

A huge PNG, unchanged artifacts or a missing file are expected behaviour or a limit, not a broken conversion.

A 9 MB PNG from a 1.5 MB photo is normal, since lossless storage of photographic noise is expensive. If that is too heavy for your upload, resize the JPEG to the real display width before converting, or deliver the JPEG itself. If the batch stops with a message about a batch limit, the combined results reached 64 MB. Download what finished and convert the rest in a second run.

If the PNG still shows blocky patches and halos, nothing went wrong; they came with the JPEG. Go back to a higher-quality original, or retouch in an editor. If you expected the white background to turn transparent, remember that conversion does not remove backgrounds, and run the background removal tool instead.

If a file does not appear in the list, its type is probably not JPG, PNG or WebP, or the 12-image and 48 MB limit was reached. A file that opens in a viewer with the wrong colours may carry an unusual profile, so re-save it from an editor as standard sRGB JPEG and try again.

When results look off, test with a single small JPEG to separate a file problem from a batch problem.

Keep a note of the file name that failed and its size; it makes it easy to tell whether the cause was the limit or the file itself.

JPEG photo

PNG still image

Large PNG size and unchanged artifacts are expected behaviour; transparency and sharpening need different tools.