File Encoding Detector (UTF-8, UTF-16, BOM)

Upload any file; the tool sniffs its encoding via BOM detection, byte pattern analysis, and validity checks. Useful for diagnosing "weird characters" issues or confirming a CSV/log file is UTF-8 before importing.

How to use the File Encoding Detector (UTF-8, UTF-16, BOM)

Upload a file (up to about 5 MB). The tool inspects it for a byte-order mark, analyses its byte patterns, and runs validity checks to report the most likely encoding — UTF-8, UTF-16 BE/LE, ASCII, or Latin-1.

Working out what encoding a file uses

A text file is just bytes; the encoding is the convention that maps those bytes to characters, and it is not stored anywhere inside the file. Guess wrong and you get mojibake — café turns into café. The classic “weird characters” bug almost always traces back to an encoding mismatch at import time.

Upload a file and this detector looks for a byte-order mark, analyses byte patterns, and validates the bytes against each candidate to report the most likely encoding. Run it before importing a CSV or log to confirm it is UTF-8. To validate a specific byte sequence as UTF-8, use the UTF-8 validator; to fix line endings once you know the encoding, the line ending converter.

Common use cases

  • Import prep — confirm a CSV is UTF-8 before loading it into a database.
  • Mojibake diagnosis — find the real encoding behind garbled characters.
  • BOM detection — see whether a file carries a UTF-8 or UTF-16 byte-order mark.
  • Legacy data — tell ASCII from Latin-1 in an old export.
  • Pipeline checks — verify files match the encoding your tooling expects.

Frequently asked questions

How does it detect the encoding?

It checks for a byte-order mark, analyses the byte patterns, and validates the bytes against each candidate encoding.

Is detection always certain?

No. A BOM is definitive, but without one, ASCII, UTF-8, and Latin-1 can overlap, so the tool reports the most likely match.

Does my file upload anywhere?

No. It is read in your browser and analysed locally; nothing is sent to a server.

What is the size limit?

Around 5 MB, which is far more than enough to sample a file’s encoding reliably.
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