A SMALL TOOL FOR TIDIER DATA
A clean sheet.
A fresh start.
Clean a local CSV in your browser. Trim whitespace, remove empty and duplicate rows, then preview and download the result.
Your data stays in this tab. No uploads, accounts or saved history.
01 Bring your CSV
Up to 2 MiB · 20,000 rows · 200 columns
The first row is treated as data. Your original text stays unchanged when you clean.
02 Set things straight
Trimming runs first, then empty rows, then duplicates.
Start with a file, pasted text or the built-in sample.
03 Check the proof
FIRST 50 ROWS / ALL COLUMNSGood data starts with a closer look.
Your cleaned rows will appear here. Try the sample to see what changes.
Values stay as text here. Spreadsheet apps may interpret formulas beginning with =, +, - or @ when opening CSV. Review untrusted data before opening it there.
WORKSHOP NOTES
A few useful answers.
No mystery steps.
Just your data, tidied.
How do I clean a CSV?
Choose a UTF-8 file or paste CSV text, select its delimiter, choose cleaning options and select Clean & preview. Review the row counts and preview, then select Download CSV. The first row is treated as data, so cleaning applies to headers too.
Does my CSV leave this tab?
No. CSV Workshop keeps your input and results in tab memory, with no uploads, analytics, accounts or browser storage. Only choosing a local file and downloading a result use your device files. Clear / reset removes the working data; reloading starts fresh.
What are the limits, and how do I fix an error?
Use UTF-8 CSV up to 2 MiB, 20,000 rows and 200 columns. The preview shows the first 50 rows; the download includes all cleaned rows. Quoted fields, doubled quotes and embedded line breaks are supported. Rows must have consistent field counts, except blank lines. Fix the delimiter or quotes and try again. Errors preserve your text and previous preview, but disable downloading until cleaning succeeds.
How are duplicates and spreadsheet formulas handled?
Trimming happens first, followed by empty-row removal and exact, case-sensitive duplicate removal. The first matching row is kept. Values, including leading zeros and formulas, remain strings here. Formulas are preserved in the download and may be interpreted by spreadsheet apps; this tool does not neutralize them.