What is a file magic number?

A magic number is a constant numerical or text value at the absolute beginning of a file, used to identify its true format.

How does the MIME type detector work?

It reads the first few bytes (hex signatures) of a file using HTML5 FileReader, bypassing spoofed extensions.

Can it detect corrupt file structures?

Yes, if the header bytes do not match the extension, it flags the mismatch.

Which formats are supported?

It supports PNG, JPEG, GIF, PDF, ZIP, RAR, EXE, MP3, MP4, and text format magic numbers.

Are my files uploaded to any server?

No, files are inspected locally in memory. We never upload your documents.

MIME stands for Multipurpose Internet Mail Extensions, a standard that indicates the nature and format of a document.

How do I fix a file extension mismatch?

The detector displays the correct extension, allowing you to rename the file correctly.

Does it check binary structure?

Yes, it reads the hex signatures directly from the file's raw binary array.

Is there a size limit for uploads?

No, because only the first few kilobytes are parsed, even multi-gigabyte files process instantly.

Is the MIME Type & File Signature (Magic Number) Detector tool on HandyToolsBox safe to use?

Yes, absolutely! The MIME Type & File Signature (Magic Number) Detector runs entirely locally inside your browser sandbox. No file uploads or textual contents are ever sent to our remote servers, protecting your security and privacy 100%.

Do I need to install any software to use the MIME Type & File Signature (Magic Number) Detector?

No installation, extensions, or setup is required. All tools are fully web-based and execute using native HTML5 and JavaScript client-side operations.

MIME Type & File Signature (Magic Number) Detector

Free online mime type & file signature (magic number) detector tool. Detect the true MIME type and file signature (magic number) of any file online. Identify disguised or mislabeled files by their binary header. Free tool, no signup needed. No signup or download required, processes completely in your browser for maximum privacy.

MIME Type & File Signature (Magic Number) Detector

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