CSV Cleaner & Converter

Clean a messy CSV, or convert CSV to JSON

Spreadsheets and exports produce messy CSV files: stray whitespace around values, empty rows left behind by deleted data, the same record pasted twice. This tool fixes the common problems and, for developers, converts between CSV and JSON — all in your browser, so the file never leaves your device.

What the cleaner does

• Trim whitespace — removes leading and trailing spaces inside every cell, the single most common cause of "why won't these two values match?"
• Remove blank rows — drops rows that are entirely empty.
• Remove duplicate rows — keeps the first occurrence of each identical row and drops the rest.

You pick which passes to apply, and you see how many rows changed.

CSV to JSON (and back)

CSV → JSON turns your file into a JSON array of objects, using the header row as keys — the shape most APIs and scripts expect. If a header cell is empty, it becomes a positional key like column_3 so no column is silently dropped. JSON → CSV does the reverse: give it an array of objects and it produces a CSV whose columns are the union of every object's keys.

Why local matters for spreadsheets

CSVs are where personal and business data live: customer lists, transactions, email addresses. Uploading them to a random web tool to "clean" them is exactly the habit worth breaking. Here the parsing runs in your browser, so there is no server that ever sees a single row — verifiable in your network inspector, and it keeps working in airplane mode.

A note on very large files

The tool holds your file in memory while it works, so extremely large CSVs can strain a phone's memory. If a file is large you'll get a heads-up before processing, and on a desktop you have a lot more headroom.