BOM Remover Free Online Tool 2026

Last updated March 22, 2026

What Is a BOM?

A BOM (Byte Order Mark) is a special Unicode character (U+FEFF) that appears at the very beginning of a text file. It was originally used to indicate the byte order (endianness) of UTF-16 and UTF-32 encoded files. In UTF-8, byte order is irrelevant, but some tools — notably Microsoft Notepad and Excel — still prepend a UTF-8 BOM (0xEF 0xBB 0xBF) to UTF-8 files.

The UTF-8 BOM is invisible in most text editors but causes real problems in code: it breaks PHP scripts (output before headers), corrupts CSV imports, causes JSON parse errors, and confuses shell scripts that check the first line for a shebang (#!/bin/bash).

Detecting a BOM

# Check if a file has a UTF-8 BOM
hexdump -C file.txt | head -1
# BOM shows as: ef bb bf at the start

# Using file command
file file.txt
# Output: "UTF-8 Unicode (with BOM) text"

# Python: detect and strip BOM
with open('file.txt', 'rb') as f:
    raw = f.read()
    if raw.startswith(b''):
        print("BOM detected")
        raw = raw[3:]  # strip it

Removing BOMs in Bulk

import os, glob

def strip_bom(filepath):
    with open(filepath, 'rb') as f:
        content = f.read()
    if content.startswith(b''):
        with open(filepath, 'wb') as f:
            f.write(content[3:])
        return True
    return False

# Strip BOM from all .csv files recursively
for path in glob.glob('**/*.csv', recursive=True):
    if strip_bom(path):
        print(f"Stripped BOM: {path}")

Preventing BOMs

Configure your editor to save files without BOM. In VS Code, open the Command Palette, run "Change File Encoding", and select "UTF-8" (not "UTF-8 with BOM"). In Notepad++, go to Encoding → "Encode in UTF-8" (without BOM). For new files, add an .editorconfig to your project:

[*]
charset = utf-8
# Note: editorconfig doesn't have a "no-bom" option,
# but most editors respect utf-8 as meaning no BOM