N
NJHTools

CSV Viewer & Editor

Open a CSV or TSV file as an editable table. Sort, filter, remove duplicate rows, transpose and reorder columns, then convert it to a Markdown table, SQL INSERT statements, JSON, HTML or YAML. Large files work too, and your data never leaves the browser.

6 rows × 5 columns

#
1
2
3
4
5
6
Convert to
6 rows

How to view, edit and convert a CSV file

  1. Open your CSV. Paste CSV or TSV text, drop a .csv or .tsv file on the input box, or click Open file. The delimiter (comma, semicolon, tab or pipe) and quoting are detected automatically.
  2. Edit the table. Click any cell to edit it. Rename columns in the header, add or delete rows and columns, and drag a column or use its arrows to reorder it. Undo reverts any change.
  3. Clean and organise. Sort by any column, filter rows by a search term, remove duplicate rows, trim stray whitespace, or transpose rows and columns.
  4. Convert and export. Choose CSV, TSV, JSON, Markdown, HTML, SQL INSERT or YAML, adjust options such as the delimiter or SQL table name, then copy the result or download the file.

Export formats at a glance

  • CSV / TSV: RFC 4180 quoting, with a choice of comma, semicolon, pipe or tab and LF or CRLF line endings.
  • JSON: an array of objects keyed by the header, with optional number and true/false detection. Values with leading zeros such as ZIP codes stay strings.
  • Markdown table: ready for GitHub READMEs, issues and documentation.
  • HTML table: escaped <table> markup with an optional <thead>.
  • SQL INSERT: multi-row or single-row inserts with dialect quoting and an optional CREATE TABLE.
  • YAML: a list of mappings, quoting values like yes, no and 007 so YAML parsers keep them as text.

Tips for messy CSV files

Files exported from European versions of Excel often use semicolons because the comma is the decimal separator; auto-detection handles this, and you can force a delimiter if a file is ambiguous. Fields that contain the delimiter, quotes or line breaks must be wrapped in double quotes, and the editor reads and writes them that way.

Before importing data into a database, run Trim whitespace and Remove duplicate rows, then sort by a key column to spot blanks and outliers. For a quick two-way conversion without editing, use the CSV ↔ JSON Converter; to hand a spreadsheet to someone, export JSON and turn it into a real .xlsx file with JSON to Excel.

Related tools

Frequently Asked Questions

How do I open and view a CSV file online?↓

Drop the .csv or .tsv file onto the input box or click Open file. It is shown as a table with a sticky header and row numbers, and you can scroll through tens of thousands of rows. The file is read by your browser and never uploaded.

How do I convert CSV to a Markdown table?↓

Load the CSV, choose Markdown under Convert to, and click Copy. The output is a GitHub-flavoured Markdown table with padded columns, right-aligned numeric columns, escaped pipe characters, and line breaks inside cells turned into <br>.

How do I convert CSV to SQL INSERT statements?↓

Choose SQL INSERT, enter the table name and pick a dialect (PostgreSQL/SQLite, MySQL or SQL Server). Strings are quoted with single quotes escaped, numeric columns stay unquoted, and empty cells can become NULL. You can group up to 1,000 rows per INSERT and add a CREATE TABLE statement with inferred column types.

Can I change the delimiter of a CSV file?↓

Yes. The input delimiter is detected automatically and can be overridden. On export, choose CSV with a comma, semicolon or pipe, or TSV for tabs, and LF or CRLF line endings. Semicolon CSV with CRLF is what Excel expects in many European locales.

How do I transpose a CSV?↓

Click Transpose. Rows become columns and columns become rows; if the first row is the header, the first column of the result becomes the new header. Transposing again restores the original. Up to 500 resulting columns are supported.

How large a CSV file can I edit?↓

Only the visible rows are drawn, so files with 50,000 or more rows scroll and edit smoothly. The practical limit is your device's memory; files up to about 200 MB can be opened. The export preview shows the first 200 rows, but Copy and Download always include every row.

What is the difference between this and the CSV to JSON converter?↓

The CSV ↔ JSON converter is a quick two-way text conversion. The CSV Viewer & Editor is a table editor: use it to look through a file, fix cells, sort, filter and clean the data, and export it to several formats. To produce an .xlsx spreadsheet, use JSON to Excel.

Last updated: