CSV Merge

• CSV Split
• CSV to Excel
• CSV Viewer
• CSV Tools

This free CSV merge tool runs in your browser. Add multiple CSV files (via file picker or drag-and-drop), choose delimiter and encoding, optionally use the first row as header so the header is written only once, and merge into a single CSV. Preview the result, then download or copy to clipboard. All processing is client-side.

• Merge multiple CSVs into one: Combine any number of CSV files in order. The output is a single CSV file with all data rows (and one header row if first row as header is enabled).
• Auto or custom delimiter: Choose Auto to detect the delimiter from the first file, or pick comma, semicolon, tab, or pipe. All files are read with the same delimiter.
• Encoding for file upload: Select UTF-8, Windows-1252, or ISO-8859-1 so files from different regions or legacy exports are read correctly.
• First row as header: When enabled, the first row of the first file is the header; it is written once. Data rows from all files are appended; duplicate headers in other files are skipped.
• Add files by picker or drag-and-drop: Select multiple CSV files or drop them onto the area. Remove or reorder files in the list before merging.
• Preview and copy: After merging, the result is shown in a preview area. Download the merged CSV or copy it to the clipboard.
• Quoted fields: The parser handles quoted CSV fields and escaped quotes correctly in each file.
• Client-side and private: Merging happens in your browser; files are never sent to a server.

Combining multiple CSV files into one simplifies analysis, import into databases or spreadsheets, and sharing. Use this tool when you have split exports, monthly files, or multiple sources that share the same structure.

• Single file for analysis: Merge monthly or weekly exports into one CSV for pivot tables, charts, or scripts.
• Import and ETL: Many tools accept one CSV. Merge first so you do not have to import multiple files.
• No server: Merging runs in your browser, so sensitive data never leaves your device.

Each file is read with the chosen encoding and parsed with the selected or auto-detected delimiter. If First row as header is on, the first row of the first file becomes the output header and is written once; then all data rows from every file are appended in list order. The merged result is shown in the preview; you can download or copy it.

• Add files: Add one or more CSV files. The order in the list is the merge order. Set encoding and delimiter (Auto or manual).
• First row as header: When enabled, the first file contributes its first row as the header; subsequent rows from all files (and headers from other files) are treated as data and appended. When disabled, every row from every file is appended as-is.
• Merge: The tool reads each file, parses rows with the delimiter, and appends rows in order. Quoted fields are handled correctly.
• Preview and download: The merged CSV is shown in the preview. Download the file or copy to clipboard. All processing is client-side.

These options control how each file is read and how the merged output is built.

• Delimiter (Auto or manual): Auto detects the separator from the first line of the first file (comma, semicolon, tab, or pipe). All files are read with the same delimiter. Choose a specific delimiter when Auto does not match.
• Encoding (file upload): UTF-8 is the default. Use Windows-1252 or ISO-8859-1 for files that show wrong characters (e.g. accented letters) when read as UTF-8. The merged output is UTF-8.
• First row as header: When enabled, the first row of the first file is written once as the header. All other rows from all files are appended as data. Headers in the second and later files are not treated specially; they are appended as data rows. So ensure only the first file has a header row if you want a single header in the output.

Use Auto for most cases. If the merged result looks wrong, set the delimiter explicitly so all files are read with the same separator.

• Comma: Standard for CSV in English locales. Auto usually detects it.
• Semicolon: Common in European locales. Choose if your CSVs use semicolons.
• Tab: Used for TSV. Choose when fields are tab-separated.
• Pipe: Often used in data pipelines. Choose when fields are pipe-separated.

Powered by browser APIs and client-side processing.