Editing CSV files shouldn't be painful
You have a CSV file that needs fixing. Maybe there are typos in a column, missing values to fill in, or rows to delete. You could open it in a text editor and wrestle with commas and quotes, or you could import it into Excel — but Excel mangles dates, strips leading zeros, and silently corrupts data types.
Viztab gives you a proper spreadsheet interface for CSV editing. It respects your data types, handles quoted fields correctly, and lets you save back to clean CSV when you're done.
Everything you need to edit CSV data
- Click-to-edit cells — click any cell to edit its value, just like a normal spreadsheet
- Add, delete, and rearrange — insert rows and columns, delete what you don't need, drag to reorder
- 370+ formulas — compute new columns with VLOOKUP, IF, CONCATENATE, date math, and hundreds more
- Sort and filter — sort by any column, filter rows by value, then export just the data you need
- Find and replace — fix data across thousands of cells in seconds
No data corruption
Excel is notorious for silently converting CSV data. Zip codes like "07024" become 7024. Gene names get turned into dates. Long numbers lose precision. Viztab imports your CSV data exactly as-is and writes it back without surprises.
Viztab also auto-detects delimiters (comma, tab, semicolon, pipe) so you don't need to fiddle with import settings. It handles quoted fields, escaped characters, and multi-line values correctly.
How it works
Import your CSV
Drag and drop your CSV file, or click to browse. Files with millions of rows are supported.
Edit your data
Click cells to edit, add formulas, insert rows and columns, sort, filter, find and replace.
Export as CSV
Save your edited data back to CSV (or XLSX). The output is clean, properly quoted, and ready to use.
Frequently asked questions
Yes. Viztab is built for large files. You can open, edit, and save CSV files with millions of rows without the browser slowing down or crashing. Most online CSV editors cap out at a few thousand rows — Viztab has no such limit.
Viztab reads your CSV data faithfully and writes it back as clean, RFC-4180-compliant CSV. It won't mangle dates, strip leading zeros, or change number precision like Excel does.
Yes. You can use any of Viztab's 370+ formulas to compute new values, transform data, or create calculated columns. When you export back to CSV, the computed values are saved (since CSV doesn't support formulas natively). You can also save as XLSX to preserve the formulas.
Your CSV file is processed entirely in your browser. No data is sent to any server. This makes Viztab suitable for sensitive data like customer records, financial information, or medical data.
Edit your CSV file now
A proper spreadsheet editor for CSV files. No installs, no uploads, no account needed.
Open Viztab