FILE EXTENSION TROUBLESHOOTING

Invalid File Extension? Check the Real File Format

An invalid extension message can mean the filename ending is wrong, the real file format is different, or the destination does not accept that type. Check the file contents before changing the name.

The extension is only a label; the file contents are the stronger evidence

Renaming .jpg to .png, .zip to .xlsx, or another extension does not convert the file. ARADURU detects supported formats from file signatures or container structure and compares that evidence with the filename.

Check this file extension See what to check first
CHOOSE THE EVIDENCE YOU HAVE Start from the signal that is already in front of you

Do not change the original file just to test a guess. Pick the closest situation and move to the matching ARADURU check.

One file fails Check the actual file before changing it. Start here ↓ I have the exact error Start from the destination wording you can see. Open → The filename is rejected Check the exact name against verified rules. Open → Every file fails Review destination, account, browser, network, or service causes. Open →

Start with the original file. If the detected format is healthy but different from the extension, correct the label only when the evidence is clear.

No upload File stays in your browser No account Start immediately Evidence first Avoid blind file changes
CHECK THE FILE

Use the file that actually failed

Start with the same file so the result reflects the real failure, not a substitute file.

STEP 1

Enter the upload requirements

Use the limits shown by the destination website or upload form. Leave a field blank when the site does not specify that rule.

USER-PROVIDED Global

ARADURU does not guess upload limits. Enter the exact requirements shown by the destination site or upload form.

Allowed file types
Any file type is allowed unless the destination site says otherwise.
STEP 2

Choose the file

ARADURU reads the selected file locally and reruns the check when you change the requirements above.

Drop your file here or click to choose a file Any file type can be selected. Internal-format detection is available for common formats.
IDENTIFY THE FAILURE

What happened when you tried to upload?

The app says the extension is invalid

Check whether the real file format agrees with the filename before renaming it.

The file opens in one app but not another

Some apps trust the extension while others inspect the actual file contents.

You are thinking about changing the extension

Confirm the detected format first. A rename is not a conversion.

WHAT ARADURU CHECKS

A practical order before you retry

  1. Detect supported formats from signatures or container structure.

  2. Compare the detected format with the filename extension and common aliases.

  3. Check supported structure so corruption is not mistaken for a simple extension problem.

  4. Change the filename only when the detected format clearly supports that change.

AFTER THE CHECK

Use the result to choose between renaming, converting, or deeper diagnosis

If the contents are a healthy file of another type, a corrected extension may be appropriate. If the destination needs a different type, use a real conversion. If the structure is damaged, preserve the original and troubleshoot the file instead.

Need a deeper format-specific diagnosis? Continue with the full File Check after the extension and detected format are compared.

Open the Universal File Check →
RELATED UPLOAD PROBLEMS

Continue from the evidence you actually have

Open the full Upload Check → Invalid File Format? Check What the File Actually Contains → View all upload problems →