CSV / Excel Utilities

Convert, merge, split and dedupe CSV & JSON files.

A free all-in-one CSV toolkit: convert CSV to JSON and JSON back to CSV, merge several CSV files into one (aligning columns by header), split a big CSV into smaller row-chunks, and remove duplicate rows by the whole row or a key column. Handles commas, semicolons, tabs and pipes with proper quoted-field support. Runs fully in your browser — nothing is uploaded.

How to use CSV / Excel Utilities

  1. Choose a tool tab

    Pick CSV to JSON, JSON to CSV, Merge, Split or Dedupe, so this free online CSV toolkit runs the exact spreadsheet job you need entirely in your browser.

  2. Load your data

    Paste your CSV or JSON into the input box, upload a .csv file, or click Sample to try it out; the delimiter is auto-detected when you upload a file.

  3. Set the options

    Tell the tool whether the first row is a header, pick the comma, semicolon, tab or pipe delimiter, and enable number and boolean detection for CSV to JSON.

  4. Tune the operation

    Add files to merge, set rows per file to split a big CSV, or choose a key column and case rules to dedupe repeated rows precisely.

  5. Review the result

    Your converted JSON, clean CSV, merged sheet or deduplicated rows appear instantly in the output panel, with live row and column counts for each job.

  6. Copy or download

    Copy the output to your clipboard or download it as a .json or .csv file, ready for your API, Excel, Google Sheets or any database export.

Frequently asked questions

How do I convert CSV to JSON (or JSON to CSV)?

Pick the CSV → JSON tab, paste your CSV or upload the file, and the JSON array appears instantly — ready to copy or download. To go the other way, use JSON → CSV: paste an array of objects and get a clean, Excel-ready CSV with a header row. The delimiter is auto-detected on upload.

Is my data uploaded anywhere?

No. Every conversion — CSV↔JSON, merge, split and dedupe — runs entirely in your browser with JavaScript. Nothing you paste or upload is sent to a server, logged or stored, so it's safe for confidential exports.

Which delimiters and formats are supported?

Comma (CSV), semicolon (the default in many European Excel locales), tab (TSV) and pipe. Quoted fields, escaped double-quotes ("") and both Windows (CRLF) and Unix (LF) line endings are handled. When you upload a file the delimiter is auto-detected.

How does Merge align columns?

With a header row, the merged file's columns are the union of every file's headers (in first-seen order) and each file's rows are re-mapped to that layout — so files with columns in a different order, or with extra/missing columns, still line up. Without a header, rows are simply stacked.

How are duplicates detected?

By default a row is a duplicate only when every cell matches a row already kept; the first occurrence wins. Pick a column under "Match on" to dedupe by a key (e.g. email) instead, and optionally ignore surrounding spaces or letter case.

Can it open a real Excel (.xlsx) file?

This tool works with CSV/TSV text, which every spreadsheet app can export (File → Save As → CSV). For binary .xlsx workbooks, export the sheet to CSV first, then paste or upload it here.

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