"Upload failed." "File format not supported." "Image exceeds the maximum size." These errors rarely explain exactly what's wrong, which turns a simple photo upload into a frustrating guessing game. Most causes fall into a short list, and working through it in order usually finds the problem quickly.
Read the Error Message Carefully
Vague as they often are, upload errors usually hint at one of these:
| Error hints at | Likely issue |
|---|---|
| "Format not supported" | Wrong file type (HEIC, WebP, RAW) |
| "File too large" | Exceeds the size limit in KB/MB |
| "Invalid dimensions" | Pixel width/height outside allowed range |
| Generic "upload failed" | Could be size, format, connection, or a damaged file |
Step 1: Check the Format
Many forms only accept JPG and sometimes PNG. If your photo is:
- HEIC (common from iPhones) — convert with HEIC to JPG.
- WebP — convert to JPG using Image Editor if the platform doesn't support it.
- A screenshot saved oddly — re-save or re-export as a standard JPG or PNG.
Step 2: Check the File Size
If the file is too large:
- Note the exact limit stated by the form.
- Resize the image with the Image Editor if it's much larger than needed.
- Compress with Image Compress.
- Recheck the file size before re-uploading.
For getting under specific common targets, see how to compress a photo under 100 KB.
Step 3: Check the Dimensions
Some forms specify exact or minimum/maximum pixel dimensions separately from file size — for example, "at least 600×600 pixels" or "exactly 350×450." Check the image's dimensions and adjust with the Image Editor and the Aspect Ratio Calculator if needed.
Step 4: Rule Out a Damaged File
If format, size and dimensions all look correct but the upload still fails:
- Try opening the file in a different app to confirm it isn't corrupted.
- Re-export or re-save the image from its original source.
- Try uploading from a different device or browser in case the issue is on that end.
Step 5: Check Your Connection
Occasionally, upload failures are simply a slow or interrupted internet connection rather than anything about the file. Try again on a more stable connection, or a smaller file size, if uploads keep timing out.
A Reusable Checklist
Before uploading any image to a form or portal:
- Format matches what's accepted (usually JPG).
- File size is under the stated limit.
- Dimensions match any stated requirement.
- The file opens correctly elsewhere, confirming it isn't damaged.
Following this order — format, then size, then dimensions, then file integrity — resolves the overwhelming majority of rejected image uploads without needing to guess.
