How to use this database
Every entry records the measurable rules a portal enforces, pixel dimensions, aspect ratio, accepted formats, print resolution, and the file size window, in a form the tools can act on directly. Open a requirement, drop in your photo, and the output is built to those numbers without you configuring anything.
Entries marked has a minimum are the ones that catch people out. A file can be rejected for being too small as easily as for being too large, and most tools have no concept of a lower bound at all. US online passport renewal refuses anything under 54 KB; China's COVA system wants a file between 40 and 120 KB.
On accuracy
Requirements change without notice, and portals do not always publish the change. Every entry shows the date we last checked it and links to the official source. Confirm there before you submit, especially for anything with a deadline or a fee attached. This is a tool, not an authority.
If you find an entry that no longer matches the official guidance, please let us know so it can be corrected.