UTF-8 BOM Adder

Add UTF-8 BOM to text files for Excel compatibility and fix Excel encoding issues

Upload Text File

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Drag and drop your text file here (CSV, TXT, etc.), or click to browse

Supported formats: CSV, TXT, TSV, and other text files

Maximum file size: 50MB

What is UTF-8 BOM?

UTF-8 BOM (Byte Order Mark) is a special character sequence (EF BB BF in hexadecimal) placed at the beginning of text files to identify the file as UTF-8 encoded. While optional in the UTF-8 specification, many Windows applications like Microsoft Excel require the BOM to correctly interpret UTF-8 files.

When to Use This Tool

Use this tool when opening CSV files in Excel shows garbled characters, when exporting data with international characters, when working with multi-language datasets, or when preparing CSV files for Excel import that contain special characters, accents, Chinese, Japanese, or other Unicode text.

How It Works

Simply upload your text file (CSV, TXT, TSV, etc.), and the tool adds the three-byte UTF-8 BOM sequence (0xEF, 0xBB, 0xBF) to the beginning of your file. The rest of your file content remains completely unchanged. Download the enhanced file and open it in Excel - your special characters will display correctly!

Add the three-byte UTF-8 BOM (EF BB BF) to a UTF-8 text file. This helps applications such as Excel recognize the encoding of CSV files. Processing happens in your browser and preserves the file content.

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