Upload troubleshooting

How to check a file before uploading it

A file can be below the size limit and still fail. Check the mechanical properties in the order that upload forms usually inspect them.

1. Confirm the exact format

Do not rely only on the filename. A file called photo.jpg can contain a different format, and some portals allow JPG but not WebP or HEIC. Use the extension and the browser’s decoded type together.

2. Check bytes and pixels separately

KB or MB is the storage size. Width and height are the pixel dimensions. Resizing a photo can change pixels without fixing an oversized file, while compression can change bytes without meeting a minimum dimension.

3. Check the ratio before resizing

Forcing a rectangle into a square stretches the subject. Crop the composition first, then resize. If a portal states a ratio, use its ratio rather than a generic “passport” preset.

4. Rename cautiously

Use a short filename with letters, numbers, hyphens or underscores. Very long names, reserved characters and unusual punctuation can break older upload forms.

5. Treat a green check as a preflight, not approval

A browser can check file mechanics. It cannot decide whether a face, signature, background or document content satisfies the receiving authority. Keep the official requirement page open and treat it as the final rule.

Check a file with Upload Preflight Checker →

Sources and limits

This guide explains general file mechanics. Requirements vary by portal; confirm the exact receiving service’s published rules before submitting.