File mime type checker

0 of 0 ratings

About the File MIME Type Checker

The File MIME Type Checker reads the magic bytes of any uploaded file and reports its actual type, regardless of the extension. It is useful when troubleshooting upload errors.

How to use it

Drop a file into the upload area.
The tool reads the magic bytes and reports the MIME type.

Privacy

File analysis happens in your browser; the file is not uploaded.

A file's MIME (Multipurpose Internet Mail Extensions** type tells servers, browsers, email clients and upload systems how to treat it — whether it is an image, a PDF, a ZIP archive or plain text. This checker inspects a file you choose and reports its exact MIME type, so you can confirm a server, import or attachment will handle it correctly.

Getting the MIME type right matters: an upload endpoint that expects image/pjpeg but receives image/jpeg may reject a valid file, anda mislabeled extension can make a browser offer the file for download instead of opening it. A quick check removes the guesswork.

How to Check a File's MIME Type

Select a file from your device.
Read the reported MIME content type.
Compare it against what your server, filter or handler expects, adjusting code or content type as needed.

Practical Use Cases

Confirm an uploaded image will pass a shop's validation, debug why a downloadable asset is served with the wrong content type, document what MIME types a legacy system actually produces, and verify an attachment ships as the type your recipient's tooling expects. Because the check happens locally, you can inspect even sensitive or unpublished files safely.

MIME type checker — common questions

What is a MIME type, exactly?

A MIME type is a two-part label, like image/png or application/pdf, that tells software how to interpret a file. The checker returns the precise content type for the file you select.

Why does the reported MIME type sometimes differ from the file extension?

The MIME type is derived from the file's actual content, not its extension. That is why a file renamed with a wrong extension can still report its true type — exactly the mismatch an upload or email handler may trip on.

Does checking upload the file anywhere?

No. The file is inspected locally in your browser and never sent to a server, so it is safe to check private or confidential documents,source code and other material you prefer to keep to yourself.