Data Cleaner

Clean messy columns fast (trim, normalize, dedupe, standardize dates) so your downstream reports stop breaking. Runs locally in your browser.

Upload a file

CSV / TSV / XLSX / XLS (first sheet used)

File:not loaded

If you upload a .txt, it works when it’s actually CSV/TSV-style (header row + delimiter).

Delimiter Preview rows

Safety: your file is read locally in your browser. Use Masker if you need to share samples.

Run summary

What changed after cleaning

Rows: — Cols: — Kept: 0 Updated cells: 0 Removed rows: 0 Dedup key:—

Privacy: processed locally in your browser. Nothing is uploaded unless you choose to share details for help.

1) Universal cleanup

Trim whitespace

" abc " → "abc"

Collapse multiple spaces

"a b" → "a b"

Normalize empty values

treat "", "null", "n/a" as empty

Drop blank rows

remove rows where every cell is empty

2) Standardization

Standardize column names

convert headers to snake_case (non-destructive preview)

Normalize numbers

remove commas/currency; 1.0 → 1

Uppercase state codes

if column looks like State / Province, keep 2-letter uppercase

Lowercase emails

normalize email casing

3) Dedupe & date fixing

Pick columns used to detect duplicates. If empty, dedupe uses the full row.

Fix common date formats

tries to output ISO like 2026-02-18 where possible

Date output

Dedupe keeps the first occurrence and removes later duplicates.

Preview

Before vs after (first N rows)

Audit notes

What the tool detected

Load a file, pick options, then run cleaning to generate an audit.