Free Online CSV Editor – Edit CSV Files in Your Browser

Edit, sort, format, and clean CSV data online without installing software or uploading files to a server. This free browser-based CSV editor handles everything from quick cell edits to bulk data transformations—all while keeping your data private on your device.

Unlike desktop tools such as Excel or Google Sheets, this CSV editor requires no installation, no account, and no internet connection after loading. Open a CSV, TSV, or TXT file, paste data from your clipboard, or start from a blank spreadsheet and begin editing immediately.

Key Features

Multi-level sorting – Sort by multiple columns at once with ascending or descending order and custom priority
Column formatting – Format dates (short, medium, long, ISO), numbers (integer, decimal, currency, percentage, roman numerals), text case (uppercase, lowercase, title case, camelCase, snake_case, and more), time, and phone numbers
Category mapping – Remap column values into categories like boolean, yes/no, priority, status, or custom groups
Data cleaning – Trim whitespace, normalize spacing, extract numbers, remove duplicate rows, and remove empty rows
Find & Replace – Search across all columns or a specific column with full regex support
Split column – Break a single column into multiple columns by a delimiter
Fill empty cells – Replace blank cells with a default value, the value above, or a custom pattern
Prepend & Append – Add text before or after every value in a column
Drag-and-drop reordering – Rearrange rows and columns by dragging them into position
Undo & Redo – Full change history with Ctrl+Z / Ctrl+Shift+Z keyboard shortcuts
Multiple export formats – Download your data as CSV, TSV, or JSON
Pagination – Browse large files page by page with configurable page sizes

How to Edit a CSV File Online

Load your data – Click “Open” to upload a CSV, TSV, or TXT file. You can also paste data from your clipboard or create a new blank spreadsheet.
Edit cells – Click any cell to change its value. Add or remove rows and columns as needed.
Transform your data – Use the toolbar to sort columns, format values, clean up inconsistencies, or find and replace text.
Export your results – Download the finished file in CSV, TSV, or JSON format.

Common Use Cases

Cleaning up exported data – Remove duplicates, trim whitespace, and fix formatting before importing into another system
Preparing mailing lists – Standardize names, format phone numbers, and fill in missing fields
Reformatting dates and numbers – Convert dates to ISO format, currencies to a consistent style, or numbers to percentages
Quick data inspection – Open a CSV to browse its contents without launching a full spreadsheet application
Merging and splitting columns – Split comma-separated values into individual columns or prepend/append text to unify data
Converting between formats – Turn a CSV into TSV or JSON for use with different APIs or databases

Best Practices for Editing CSV Data

Keep a backup – Download your original file before making bulk changes. The undo history clears when you close the page.
Use headers – Toggle the header row on so column names appear in sort and format dialogs.
Clean before formatting – Trim whitespace and remove empty rows first; formatting works best on consistent data.
Test regex patterns – Use Find & Replace in preview mode to verify your regex matches the right cells before applying changes.

Why Choose This Online CSV Editor?

✅ 100% Free – No hidden fees, premium tiers, or usage limits
✅ Privacy First – All processing happens locally in your browser; files are never uploaded to any server
✅ No Sign-Up Required – Start editing immediately without creating an account
✅ Works Offline – No internet connection needed after the page loads
✅ Large File Support – Built-in pagination keeps performance smooth regardless of file size
✅ Cross-Platform – Runs on any device with a modern browser—Windows, Mac, Linux, or Chromebook

Privacy & Security

Every operation—sorting, formatting, cleaning, and exporting—runs entirely in your browser. Your CSV files are never sent to a server, making this tool safe for editing confidential business data, customer lists, financial records, or any information you need to keep private.

Frequently Asked Questions

What file types can I open?
You can open CSV, TSV, and TXT files, or paste tab- or comma-separated data directly from your clipboard.

Is there a file size limit?
There is no hard limit. The editor uses pagination to keep the interface responsive even with very large files containing thousands of rows.

Can I export to formats other than CSV?
Yes. You can export your data as CSV, TSV (tab-separated), or JSON.

Is my data sent to a server?
No. All processing happens in your browser. Your data never leaves your device.

Does Find & Replace support regular expressions?
Yes. You can use full regex patterns in both the search and replace fields, and target all columns or a specific column.

Can I undo changes?
Yes. Use Ctrl+Z (or Cmd+Z on Mac) to undo and Ctrl+Shift+Z (or Cmd+Shift+Z) to redo. The full change history is available as long as the page remains open.

How is this different from Excel or Google Sheets?
This editor is purpose-built for CSV workflows. It loads instantly in your browser with no installation or account, focuses on data transformation operations like bulk formatting and cleaning, and never uploads your data to the cloud.