Why image conversion can fail
Most failures come from file limits, damaged files, unsupported combinations, or incomplete uploads.
The file is too large
If a file exceeds the current public limit, the converter may stop before processing begins.
Uploading only the files you really need often helps avoid this.
The format pair does not fit the result you expect
Some formats do not keep transparency, and animated files may fall back to only the first frame when converted to a still-image output.
That does not always mean the tool is broken. It can simply mean the chosen pair behaves differently.
The source file is damaged or the upload did not finish cleanly
A partially downloaded file or a browser upload that did not finish properly can still look normal at first but fail during processing.
Trying again with the original file often helps you see whether the issue was temporary or file-specific.