Drag & Drop CSV files here
or click to select files (.csv)
An Online CSV Merger is a powerful digital tool designed to help you combine multiple CSV (Comma-Separated Values) files into a single, consolidated CSV file. This is extremely useful for tasks like merging data from different reports, combining datasets for analysis, consolidating contact lists, or preparing data for import into other applications.
Zenfied's CSV Merger prioritizes simplicity, speed, and data security. It operates entirely within your web browser (client-side). This crucial feature means your sensitive CSV files are never uploaded to our servers, ensuring your data remains private. The merging process is exceptionally fast as it utilizes your own computer's processing capabilities.
- Add Your CSV Files: Drag and drop your CSV files (e.g., `.csv`) onto the designated area, or click the area to browse and select files from your device. You can add multiple files at once.
- Arrange Files (Crucial for Header): After uploading, you'll see a list or previews of your files. You can reorder them by dragging and dropping them into your desired sequence. The header row from the first file in the list will be used for the merged output.
- Initiate Merge & Preview: Click the "Merge CSV Files!" button. The tool will quickly process the files and generate a text-based preview of the merged CSV content.
- Review Merged Content: Examine the preview in the text area. Ensure the header is correct (from your first file) and the data from subsequent files is appended as expected.
- Proceed to Download: If you're satisfied with the preview, click the "Proceed to Download" button.
- Download Your Merged CSV: The tool will finalize the merged CSV file directly in your browser. A download button for your new, single CSV file (e.g., `zenfied-merged-data.csv`) will appear. Click it to save your consolidated data.
- Clear or Start Over: Use the "Clear All" button to remove all uploaded files and start fresh, or "Merge Another Set" after a successful merge.
- Secure & Private: All CSV processing happens in your browser. Your files are never uploaded to any server, guaranteeing data confidentiality.
- Client-Side Processing: Leverages your device's power for fast and efficient CSV merging.
- Easy to Use: Intuitive drag-and-drop interface for quick file selection and combining.
- Supports CSV Format: Works directly with standard `.csv` files.
- Reorder Files: Easily arrange the sequence of your CSV files, which is critical as the first file determines the header.
- Header Retention: Automatically uses the header row from the first uploaded CSV file for the final merged document.
- Text Preview: See a preview of the merged CSV content before finalizing the download.
- UTF-8 Output: The merged CSV file is encoded in UTF-8 for broad compatibility.
- Completely Free: Merge your CSV files without any hidden costs, subscriptions, or limitations.
- No Installation Needed: Works directly in modern web browsers (Chrome, Firefox, Edge, Safari).
- Direct CSV Download: Get your merged data as a single CSV file, ready for use.
Our Online CSV Merger uses JavaScript to process your files directly on your device (client-side), without sending data to a server.
Here's a simplified explanation of the process:
- File Reading: When you add CSV files, the tool reads their content as text strings within the browser.
- Header Identification: The script identifies and extracts the first line (header row) from the first CSV file in your specified order.
- Data Extraction & Appending: For the first file, data rows (all lines after the header) are taken. For all subsequent CSV files, their header rows are skipped, and only their data rows are extracted.
- Content Concatenation: The script then combines the header from the first file with all the collected data rows from all files, ensuring each row is on a new line.
- Blob Creation & Output: Finally, this combined text content is formed into a Blob (Binary Large Object) with the `text/csv` MIME type and UTF-8 encoding. This Blob is then made available as a downloadable file (e.g., `zenfied-merged-data.csv`).
Because all these steps reading, parsing, concatenating, and creating the output file happen on your computer, your original CSV files and the final merged dataset never leave your device until you explicitly download the result. This ensures privacy and speed.
- Data Consolidation: Combine data from multiple sources or time periods into one master file.
- Simplified Data Analysis: Analyze a complete dataset at once instead of working with fragmented files.
- Efficient Report Generation: Aggregate data easily for comprehensive reports.
- Streamlined Contact Management: Merge various contact lists into a single, manageable CSV.
- Easier Data Import: Prepare a single file for bulk import into databases, CRM systems, or other software.
- Archiving & Record Keeping: Combine periodic data exports into a unified historical record.
- Simplified Sharing: Send one consolidated data file instead of multiple smaller ones.
- Improved Workflow Efficiency: Save time and reduce errors by automating the merging process.
Your Data Stays Yours
Client-Side Processing
All CSV merging operations occur directly within your web browser using JavaScript. Your CSV files are never uploaded or transferred to our servers.
No File Storage
We do not store, log, or monitor any of the CSV files you process or the merged results. Your data remains confidential to you.
Absolutely Free
Utilize the CSV Merger as much as you need without any cost, registration requirements, or limitations on core features.
By using this tool, you agree to our Terms of Service and Privacy Policy. We are committed to protecting your privacy and providing a secure, serverless experience for CSV merging.
Is there a limit to the number or size of CSV files I can merge?
Performance depends on your browser and your computer's memory (RAM) and processing power. Merging a very large number of files, or extremely large individual CSV files, could be slow or cause browser responsiveness issues. The total size of the final merged CSV is also limited by browser capabilities for handling large text data and creating Blobs.
What is the input and output format?
You can upload standard CSV (.csv) files. The output merged file is also a CSV file, encoded in UTF-8 to support a wide range of characters.
How is the header row handled during merging?
The tool will use the header row (the first line) from the first CSV file in your arranged list. The header rows from all subsequent files are ignored, and only their data rows are appended under the initial header.
Is this Online CSV Merger tool really secure?
Yes, it's designed with your data privacy and security as top priorities. The entire merging process happens client-side, meaning directly in your web browser. Your CSV files are never uploaded to our or any third-party servers. What happens in your browser, stays in your browser.
What happens if my CSV files have different column structures or numbers of columns?
The tool will still merge the files. It uses the header from the first file. If subsequent files have more columns than the header, that extra data will still be included in its row, potentially making the row longer than the header. If they have fewer columns, the row will be shorter. For data integrity and ease of use in other applications, it's generally best if all CSVs share a similar column structure matching the header of the first file.
What about file encoding? Can I merge files with different encodings?
The tool reads files as text based on your browser's interpretation. For best results, your input CSV files should ideally be UTF-8 encoded. If files have different encodings (e.g., ANSI, ISO-8859-1), special characters might not be preserved correctly. The final merged CSV file is always output as UTF-8.
