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CSV cleaner & deduplicator

Trim CSV fields, remove blank or duplicate records and extract columns locally.

YOUR WORKSPACEProcessed on your device

UTF-8 CSV up to 20 MB, 200,000 records, 200 columns and 2 million cells. Values stay text, including leading zeros. Changes remain in this tab.

Choose a file from your device

One UTF-8 CSV or TSV, up to 20 MB, 200,000 records and 200 columns.

Or paste CSV

DelimiterFirst record contains headers

Trim surrounding whitespaceRemove blank recordsRemove duplicate records (keep first)Case-sensitive duplicate matching

Protect spreadsheet formula-like cells with a leading apostrophe

Formula protection changes cells starting with =, +, -, @, tab or carriage return. Review before importing. Duplicates keep their first occurrence; matching uses all columns unless you select keys.

Processed on your device. Your files are never uploaded by Justility.

How privacy works

How it works

Open a CSV, inspect headers, choose trimming, blank-row removal and duplicate keys, then preview changes before exporting. Review formula protection for spreadsheet use.

Supported formats

UTF-8 CSV up to 20 MB, 200,000 rows, 200 columns and 2 million cells. CSV output; up to 200 cleaned records can be sent to batch documents.

Good to know

Duplicate or empty headers are rejected. Deduplication keeps the first matching row. Source files are unchanged; leading zeros stay text.

Worked example

Before

name,email
Ada,[email protected]
Ada,[email protected]
Sam,[email protected]

After

name,email
Ada,[email protected]
Sam,[email protected]

With all-column deduplication enabled, three input records become two. Review your chosen key columns before removing rows.

CSV cleanup preview with public sample records — Representative workspace using public sample data.

Choose what makes a record unique

Two people may share a name. Deduplicating on an email or reference column is different from comparing every field. Formula protection adds an apostrophe to spreadsheet-sensitive cell prefixes such as =, +, - and @.

CSV splitter & column extractor

Troubleshooting

Why was a row I expected to keep removed?

Check the duplicate keys and case comparison setting. Preview again from the unchanged source using a more specific key.

Practical workflows

Clean a CSV and split it for import

Choose duplicate keys, preserve text codes and split a reviewed table into smaller CSV files.

Create certificates from a CSV

Prepare recipient columns, preview a plain-text template and review a ZIP of personalized PDFs.

Common questions

Will account codes such as 00123 lose their zeros?

Values are retained as strings here. A spreadsheet may still infer numbers when opening a CSV; import that column as text.

Can I use this without an internet connection?

Yes, after you prepare this tool from Offline help and the browser retains its assets. Installation is optional. All processing dependencies are bundled locally.