Byte Order Mark Detector

Inspect the leading bytes locally, report the BOM type and length, and distinguish no-BOM data without uploading files.

Leading bytes (hex)Or inspect a local file

—Detected BOM

—BOM bytes

—Signature

ReadyA BOM is only a leading signature. No BOM does not by itself identify the file's encoding.

These tools operate on bytes and Unicode text locally. “Text to hex/binary/decimal” means the UTF-8 encoding of the text, not the numeric Unicode code point unless a tool explicitly says code point.

How to use this Byte Order Mark Detector

Detect common UTF-8, UTF-16, or UTF-32 byte order marks from bytes or a local file. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.