1. Check what the portal accepts
Before converting anything, find the exact allowed types. A portal may ask for PDF only, images only, or a small set such as JPG and PNG.
2. Use a real conversion tool
A converter changes the internal structure of the file. Simply editing .png into .jpg in the filename does not.
3. Verify the converted file
Open the new file and confirm that it is readable, complete, and actually saved in the required format.
4. Re-check the other upload rules
Format may not be the only requirement. The converted file may still need to meet a size limit, page limit, orientation rule, or filename rule.
FAQ
How do I change a file format?
Use a conversion tool that rewrites the file into the new format.
Can I change PNG to JPG by renaming it?
No. The file must be converted, not renamed.
Can changing format increase file size?
Yes. Different formats compress and store content differently, so the new file may be larger or smaller.