Combine multiple CSV files into one single file
Select 2 or more files · Max 20MB each
All CSV files merged successfully.
CSV merging is the process of combining multiple separate CSV files into one consolidated file. Instead of opening each file individually and copy-pasting data, the merger appends rows from all files into a single output while keeping only one header row at the top. This is essential when you have monthly reports, regional exports, daily backups, or batch downloads that all share the same column structure but were saved as separate files. The merged result is a clean CSV ready for analysis in Excel, importing into databases, or processing through analytics tools — all in one file instead of dozens.
Common use cases: consolidating monthly sales reports into a yearly dataset; combining customer exports from multiple regions or branches; merging daily transaction logs into weekly or monthly summaries; assembling user data from different team members; combining survey responses collected separately; preparing data from multiple sources for a single import to a CRM or analytics platform; backing up incremental database exports into one consolidated file; and merging contact lists from different sources before email marketing campaigns.
1. Click the upload area or drag 2 or more CSV files
2. Files appear in the list with their sizes
3. Click "Merge CSV Files" to combine them
4. Click "Download merged.csv" to save the combined file
5. The header from the first file is kept, all data rows are appended in order
✅ 100% free — no signup, no watermark, no limits
✅ Single header — no duplicate headers in output
✅ Preserves column order and data integrity
✅ Handles dozens of files in one operation
✅ Works on Windows, Mac, Linux, Android, iOS — any browser
✅ Privacy-first — files auto-deleted after 1 hour
✅ Files up to 20MB each
Upload 2 or more CSV files using the upload area, click Merge, and download a single combined CSV file. The tool keeps the header row from the first file and appends the data rows from all subsequent files in order.
For best results, all input CSV files should have the same column structure (same headers in the same order). The tool keeps the headers from the first file. If column structures differ, results may be misaligned. Use our CSV Cleaner tool first to standardize column names if needed.
No. Only the header from the first CSV file is kept. Subsequent files have their headers automatically removed and only their data rows are appended. This ensures a clean, single-header merged output ready for analysis or import.
There is no fixed limit on the number of files. The merge handles dozens of CSV files in one operation. Each individual file can be up to 20MB. The combined output size is also limited by available memory but typically supports merging hundreds of thousands of rows.
Yes. Files are processed on our secure server and automatically deleted within 1 hour. We never store, share, or analyze your data. The merger is also free and requires no signup.
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