CSV Editor Online
Edit CSV in a grid: sort, dedupe, transpose and export. Runs in your browser.
About this csv editor online
This CSV editor opens a CSV file as a grid you can edit in the browser, then saves it back as CSV or exports it as TSV, JSON, SQL, Markdown or HTML. It is for anyone who needs to fix a few cells, clean up an export or reshape a file without opening Excel.
Excel is often the wrong tool for a CSV. It drops leading zeros from ZIP codes, turns long IDs into 1.23E+15 and changes dates on open. Here every cell stays exactly the text that was in the file. You sort, filter, dedupe, transpose, trim and find and replace, and every step can be undone.
The grid only draws the rows on screen, so a 50,000-row file scrolls as smoothly as a ten-row one. The file is read by your browser and never uploaded, which is what you want for customer lists and payroll exports.
Features
Edit like a spreadsheet
Click any cell and type. Enter moves down, Shift+Enter moves up, Tab moves right. The header row is editable too, so renaming a column takes a second.
Delimiter detection
Comma, semicolon, tab and pipe files are detected on open, or you can force one. Quoted fields with commas and line breaks inside them are read correctly.
Clean-up tools
Remove duplicate rows, dedupe by one column, trim stray spaces, delete empty rows, and find and replace across every cell. Each step shows how many cells or rows it changed.
Reshape the table
Sort any column A to Z or Z to A, with numbers sorted as numbers. Insert, delete and move columns, add and remove rows, and transpose rows into columns.
Undo and redo
Up to 60 steps back, with Ctrl+Z and Ctrl+Y. A wrong sort or an over-eager find and replace is never final.
Six export formats
CSV with your choice of delimiter, BOM and line endings, TSV, JSON (objects or arrays), SQL INSERT statements for four databases, a Markdown table and an HTML table.
Built for big files
Rows are virtualized, and exports are built only when you copy or download. Try the 50,000-row test button to see it.
How to use the csv editor online
- 1Open a CSV file, paste text, or start from the sample.
- 2Edit cells, sort or dedupe columns, filter rows and undo any step.
- 3Pick an export format and options, then copy or download.
When to use it
Fixing an export before an import
A CRM export has a stray header, blank rows and duplicate contacts. Remove empty rows, dedupe by the email column, rename the headers and save it as UTF-8.
Switching delimiters for Excel
A colleague in Germany gets one long column when they open your CSV. Export with semicolons and a BOM, and Excel splits it properly.
Putting a table in a README
Export as Markdown and paste. Pipes inside cells are escaped so the table does not break. For more control, use the Markdown table generator.
Loading a spreadsheet into a database
Export as SQL with CREATE TABLE and multi-row INSERTs. For more control over types and keys, use the JSON and CSV to SQL converter.
Turning rows into JSON
Export as JSON to get an array of objects keyed by the header row, with numbers and booleans detected. For nested JSON from dot-path columns, the JSON converter can rebuild the nesting.
What is a CSV file, exactly?
CSV means comma-separated values: plain text where each line is a row and a delimiter splits the columns. RFC 4180 is the closest thing to a standard. It says a field containing the delimiter, a double quote or a line break must be wrapped in double quotes, and a quote inside such a field is written twice, so 12" pipe becomes "12"" pipe".
Nothing in the format says which delimiter to use, which encoding the file is in, or whether the first line is a header. That is why the same file opens fine on one computer and as one long column on another.
How do I stop Excel removing leading zeros?
Excel guesses a type for every cell when it opens a CSV. 00742 looks like a number, so it becomes 742. A 16-digit order number becomes 1.23457E+15 and loses its last digit, because Excel keeps only 15 significant digits.
The file itself is fine. Edit it here, where cells are always text, then import it into Excel with Data, From Text/CSV and set those columns to Text. Double-clicking the file skips that step and triggers the guessing.
Why does my CSV open in one column?
Your spreadsheet expects a different delimiter. In many European locales the comma is the decimal mark, so Excel uses the semicolon as its list separator. A comma file then lands in column A.
Open the file here, check the delimiter it detected, and export again with Semicolon. Turn on the UTF-8 BOM too: without it, some Excel versions read the file as Windows-1252 and show é as é.
How does Remove duplicates decide what is a duplicate?
Remove duplicates keeps the first row and drops later rows that match it cell for cell, including case and spaces. Run Trim spaces first if some rows only differ by a trailing space.
Dedupe by column compares only the selected column and ignores case, which is what you want for email addresses. The first row for each value stays, so sort first if you want to keep the newest or the largest.
Why use Mavros
| Mavros | Typical upload sites | |
|---|---|---|
| Where your file goes | Opened in your browser, never uploaded | Uploaded, sometimes kept on the server |
| Leading zeros and long IDs | Kept exactly as text | Converted like Excel does |
| Large files | 50,000 rows scroll smoothly | Row caps or a frozen tab |
| Undo | 60 steps, Ctrl+Z and Ctrl+Y | None or one step |
| Exports | CSV, TSV, JSON, SQL, Markdown, HTML | CSV only, or paid formats |
Tips
- Click a column letter to select that column for sorting, moving or deduping. The selected column is shaded in the grid.
- Filter rows only hides rows on screen. Exports always include every row, so clear the filter if you meant to delete rows.
- For a list with one value per line rather than a table, remove duplicate lines is quicker.
- To see what changed between two versions of a file, export both as CSV and compare them in the text diff checker.
- Use CRLF line endings for Windows tools and strict RFC 4180 readers. LF is fine for most code and for Git.
Questions
How do I edit a CSV file without Excel?
Open the file here, click a cell and type. Sort, filter and clean up with the toolbar, then download it as CSV. Values stay exactly as typed, with no type guessing.
Can it open a large CSV?
Yes. Only the visible rows are drawn, so 50,000 rows stay responsive. The limit is your device's memory. Files of a few hundred megabytes may be too much for a browser tab.
How do I remove duplicate rows from a CSV?
Click Remove duplicates to drop rows that match an earlier row exactly. To dedupe on one field, such as email, select that column and click Dedupe by column.
How do I change a CSV from semicolons to commas?
Open the file. The semicolon is detected automatically. Pick Comma under Export as CSV and download. Fields that contain commas are quoted for you.
What does transpose do?
It swaps rows and columns. The first column becomes the header row, and each original row becomes a column. Undo puts it back.
Should I save with a BOM?
Turn it on when the file will be opened in Excel and contains accents or non-Latin text. Leave it off for code and databases, because some parsers read the BOM as part of the first header.
Can I paste cells copied from Excel or Google Sheets?
Yes. Click Paste text and paste. Copied cells arrive as tab-separated text, and the tab delimiter is detected.
Is my CSV uploaded anywhere?
No. The file is read and edited inside your browser. Nothing is sent to a server or saved, so close the tab and it is gone unless you downloaded it.