The five checks, in the order forms apply them
- **Format.** Does the file type match the accepted list? Many portals accept only JPEG and PNG, and silently refuse WebP, HEIC or TIFF even when the extension looks similar. Fix by converting with Image Converter.
- **Byte size.** Is the file inside the stated KB range? This is where a camera photo fails hardest, since originals routinely run to several megabytes. Fix with Exact KB Photo Compressor.
- **Pixel dimensions.** Is the width and height exactly what was asked for? Fix with Exact Size Photo if you must hit exact pixels, or Resize Image if a dimension is a target rather than a rule.
- **Aspect ratio.** Does the shape match, or would meeting the pixel requirement stretch the image? Fix by cropping, never by squashing — see how to avoid stretched photos.
- **File name and encoding.** Some systems reject names with spaces, brackets, or non-ASCII characters, and a few choke on unusual byte sequences. A simple ASCII name such as `photo.jpg` avoids the whole category.
These checks happen in order and silently. A form that says only “upload failed” has usually rejected the file at the first check it performs — so fix format first, then size, then dimensions, rather than all at once.
Diagnosing before you change anything
The fastest route is to verify the file you actually intend to upload, because it may already differ from the original you remember. Image Metadata reads the header locally and prints format, dimensions and byte size in one view. Compare each printed value against the instruction, line by line, and note which one disagrees.
An instruction such as “passport-style photo, JPEG, 450 × 550 px, between 50 KB and 100 KB, taken within six months” contains four technical checks plus one human one. The technical checks are: format is JPEG, dimensions are exactly 450 × 550, size is above 50 KB and below 100 KB. The recency of the photo is not something a tool can verify — that part is on you. Real instructions vary by authority and change over time; this is an illustration of how to break one down, not a template of what yours will say.
Content rejections that no setting can fix
- **Background not plain.** Many photo requirements call for a plain backdrop. White Background Photo can even out an even-coloured backdrop; a busy background behind a person cannot be repaired automatically.
- **Subject framed wrong.** Head too small, tilted, or cropped at the crown. This is a crop and framing problem, not a compression problem.
- **Document text illegible.** If the image cannot be read at 100% zoom, no upload will improve it — re-scan at a higher DPI instead.
- **Glare, shadow or a fold across the page.** Re-shoot with even light and the page flat; filters can reduce but not remove a reflection over text.
A calm submission routine
- Read the requirement once and write down every technical value it states.
- Verify your candidate file against that list with Image Metadata.
- Fix the first mismatch only, then re-verify.
- Keep a copy of the accepted file under a clear name — most systems give you no way to download what you uploaded.
- If it is rejected again, change exactly one more variable. Guessing several at once makes the cause impossible to identify.
Common questions
The form says “invalid file” without saying why. What do I check first?
Format first — it is the check most systems run before anything else. Confirm the real format (not just the extension) with Image Metadata, convert if needed, and retry.
My file meets every stated requirement and is still rejected.
Try the unstated ones: file name characters, a margin below the byte limit, orientation, and whether the form expects a single file rather than an archive. Some portals also reject files produced by very new encoders.
Does re-saving a JPEG change its size?
Yes — re-encoding discards detail again and generally shrinks it further, while converting JPEG to PNG grows it substantially. Always re-check after any save.