File MIME type checker

Inspect common file signatures without uploading.

On your device · No account

Privacy details

File MIME type checker processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

Copy link includes the inputs you choose to share in the address. Anyone with that link can reopen them. Files and generated results are excluded. Password and key tools share settings only.

File header in hexadecimal

Choose a local file

Inspect a file on this device

Optional settings apply only to this tab.

Your result

Reset reloads the tool with its starting values and releases open files and device controls. Saved drafts stay on this device until you delete them.

Links include your inputs and settings. Anyone with the link can see them, so leave out private text. Files and generated results are left out; random draws run again.

Keyboard shortcuts

Updated 2026-09-20

File MIME type checker explained

Choose a local file to inspect its opening bytes, or paste a hexadecimal header. The tool compares those bytes with common published signatures and keeps unsupported or plain-text formats unknown. File names do not determine the result.

Next: File extension lookup

A worked example

The bytes 89 50 4E 47 0D 0A 1A 0A match a PNG header. A truncated prefix does not establish a PNG signature.

Before you use the result

Recognizes PNG, JPEG, GIF, PDF, ZIP, GZIP, BMP, ICO and ID3-tagged MP3 headers. Header matches do not validate complete files, detect malware or identify ZIP-based Office and EPUB contents. The local-file action inspects only the first 4,096 bytes.

Next: File checksum calculator

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ToolOctopus. “File MIME type checker.” Updated 2026-09-20. https://tooloctopus.com/file-mime-type-checker.

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