BOM Remover
Detect and remove the UTF-8 or UTF-16 byte order mark from text and files, or add a BOM back for Excel.
Drag & drop a text file here, or click to browse
No uploads. Your files stay on your device.
Paste text or drop a file to check it for a byte order mark.
How it works
A byte order mark (BOM) is an invisible U+FEFF character some editors and Excel
exports write at the very start of a file — EF BB BF in UTF-8,
FF FE or FE FF in UTF-16. It is harmless to read, but it breaks
shebang lines, JSON and YAML parsers, SQL imports, PHP headers and CSV column names (the
classic id instead of id). Paste your text or drop a file
and every BOM character is stripped instantly; switch to “Add a UTF-8 BOM” when you need the
opposite, for example so Excel opens a UTF-8 CSV with the right accents.
Dropped files are read as raw bytes with FileReader, so the byte order mark is
reported by name and hex signature (UTF-8, UTF-16 LE or UTF-16 BE) instead of being silently
swallowed by the decoder. Nothing is uploaded — detection, stripping and the download all run
in your browser, and the result is always saved as UTF-8 text. Use Copy result or
Download .txt to take the clean version with you.
Frequently asked questions
How do I remove the UTF-8 BOM from a file?
Drop the file on the tool or paste its contents into the box. The file is read as raw bytes, so the byte order mark is reported by name and hex signature (UTF-8 EF BB BF, UTF-16 LE FF FE, UTF-16 BE FE FF) instead of being swallowed by the decoder, and the cleaned text appears instantly. Use Copy result or Download .txt to save the version without the BOM — it is always written as UTF-8.
What is the invisible character at the start of my CSV or JSON file?
It is a byte order mark, the Unicode character U+FEFF, written by Excel, Notepad and some export scripts to flag the encoding. It is invisible in most editors but breaks JSON and YAML parsers, shebang lines, PHP headers and SQL imports, and turns your first CSV column header into something like "id" instead of "id". Removing it fixes all of those without changing any other content.
Can I add a BOM instead of removing one?
Yes — switch "What to do" to "Add a UTF-8 BOM" and the EF BB BF signature is prepended to your text. That is the usual fix for Excel opening a UTF-8 CSV with mangled accented characters, since Excel only reads the file as UTF-8 when the BOM is present.