CSV Viewer & Editor - Online Spreadsheet Tool

CSV (Comma-Separated Values) is a plain-text file format used to store tabular data. Each line represents a row, and values within a row are separated by commas (or other delimiters like tabs or semicolons). CSV files are widely used for data exchange between applications, importing/exporting databases, spreadsheet software like Excel or Google Sheets, and data analysis workflows. Their simplicity makes them universally compatible across platforms and programming languages.

Large CSV files (10MB+) can be challenging for traditional spreadsheet software. Online CSV editors like this tool allow you to view, edit, search, and filter large datasets directly in your browser without uploading data to external servers—all processing happens locally on your device. Features like pagination, column sorting, and real-time search help you navigate big files efficiently. For extremely large files (100MB+), consider using specialized data analysis tools like Python pandas or command-line utilities.

CSV files store raw data in plain text with minimal formatting—no fonts, colors, formulas, or multiple sheets. They're lightweight and universally readable. Excel files (XLSX) are binary/XML-based and support rich formatting, formulas, charts, multiple worksheets, and data validation. CSV is ideal for data portability and API integrations, while Excel is better for presentation, complex calculations, and business reporting. Most spreadsheet applications can export data to CSV format for compatibility.

While commas are the standard CSV delimiter, some files use tabs (TSV), semicolons, or pipes (|). This tool automatically detects the most common delimiter in your data when you upload or paste it. If your data uses a custom delimiter, you can adjust it during import. When exporting, the default delimiter is a comma, ensuring maximum compatibility with other applications.

This is usually an encoding issue. CSV files should ideally be saved with UTF-8 encoding to support international characters. If your file was exported from older versions of Excel or legacy systems, it might use ISO-8859-1, Windows-1252, or other encodings. To fix this, re-save the file with UTF-8 encoding using a text editor like Notepad++ or VS Code. This online editor expects UTF-8 encoded files for correct character display.

Yes! This tool provides full editing capabilities. Double-click any cell to edit its content, add or delete rows and columns using the toolbar buttons, sort columns by clicking the column headers, and search/filter data in real time. All changes are tracked locally, and you can export your modified data as a new CSV file with a single click. A "Reset" button is also available to revert to the original imported data.

Absolutely. All data processing happens entirely within your browser using client-side JavaScript. Your CSV files are never uploaded to any server. The tool uses the Papa Parse library for local CSV parsing and all editing operations are performed in memory. When you close the page, all data is cleared. This ensures complete privacy and security for sensitive data.