About this product

Messy CSVs cost hours: mixed date formats, $ and € symbols, "yes"/"Y"/"TRUE"/"1" in the same column, duplicate headers, ragged rows, stray whitespace. CSV Normalizer fixes all of it with 12 toggleable cleaning rules, 6 column tools, and a full change report so you can audit exactly what changed.

THE HONEST DATE POLICY

Ambiguous dates like 03/04/2026 (March 4 or April 3?) are NEVER guessed. If the column proves its convention (e.g. another cell reads 03/15/2026), all cells convert to ISO. If not, they're left untouched, highlighted, and flagged in the report.

PRIVACY — READ THIS

This tool runs entirely in your browser. There is no server, no upload, no tracking, and no network activity — verified zero http/https requests during testing. Your files never leave your device. You can disconnect from the internet and it keeps working.

REQUIREMENTS

Any modern browser (Chrome, Edge, Firefox, Safari). No installation. No spreadsheet app needed.

LICENSE

Single-user license. Use for your own business and client work (cleaning client CSVs is fine). You may not resell, redistribute, or share the files.

What's included

• CSV-Normalizer.html — the utility itself. One self-contained file, no installation, no account, works offline in Chrome/Edge/Firefox/Safari.
• 12 cleaning rules (each toggleable, each counted in the report): smart delimiter detection (comma/semicolon/tab/pipe), quoted-field & embedded-newline parsing, BOM cleanup, ragged-row repair, whitespace trimming, header normalization (snake_case or Title Case) with duplicate-header renaming, number normalization (US + EU formats, currency symbols, parentheses-negatives), ISO date unification, boolean standardization (→ true/false, yes/no, 1/0, or Y/N), empty row/column removal, row deduplication (exact or by key columns).
• 6 column tools: rename, reorder, drop, split (e.g. "Full Name" → first/last), merge, find-replace (plain or regex).
• Change report: rules applied with per-rule counts, cells changed, rows/columns dropped, duplicates removed, warnings — shown on screen and downloadable as .txt/.md.
• Cleaned CSV export with delimiter and quoting options.
• 3 fictional messy sample CSVs so you see it work instantly: a bank export, store orders, and a contacts list.
• CSV-Normalizer-User-Guide.pdf — the 12 rules explained, the ambiguity policy, FAQ, troubleshooting.

Key features

• 12 toggleable cleaning rules → delimiters, quoting, BOM, ragged rows, whitespace, headers, numbers, dates, booleans, empty rows/columns, and deduplication — each one counted in the report
• 6 column tools → rename, reorder, drop, split, merge, and find-replace (plain or regex)
• A change report you can audit → per-rule counts, cells changed, rows/columns dropped, duplicates removed, and warnings, on screen and downloadable as .txt/.md
• The honest date policy → ambiguous dates are NEVER guessed (see Honest limitations) — they are left untouched, highlighted, and flagged in the report
• 100% local, verified zero network → no server, no upload, no tracking; verified zero http/https requests during testing. Disconnect from the internet and it keeps working
• Nothing to install → one self-contained HTML file, no account, no spreadsheet app needed