Convert Case in CSV Files Online
Convert text columns to UPPERCASE, lowercase, or Title Case in CSV files directly in your browser. Apply case conversion to any or all text columns at once — no upload required.
How to convert Case in CSV files
- Drop your file onto the upload area. Every text column is ticked by default and the first 200 rows are shown.
- Choose the case type: UPPERCASE, lowercase or Title Case. One case type applies to every ticked column in a run.
- Adjust the columns under Apply to columns. Only text columns are listed. The All and None links tick or clear them all.
- Click Convert Case, check the preview, and download the file in the same format.
Your file is processed locally in your browser and is never uploaded. The free limit is 50 MB per file; larger files work if your device has the memory for them.
Worked example
Newsletter sign-ups were merged from two web forms, and email addresses arrive in mixed case. The mailing tool treats Jo.Bloggs@Example.COM and jo.bloggs@example.com as different contacts.
Input (CSV)
email,country,visits
Jo.Bloggs@Example.COM,NZ,3
mika.k@example.fi,fi,1
ANNA.W@EXAMPLE.DE,DE,7
r.osei@example.gh,GH,2Settings
- Case type: lowercase
- Apply to columns: email only (country unticked; visits is a number and is not listed)
Result
| country | visits | |
|---|---|---|
| jo.bloggs@example.com | NZ | 3 |
| mika.k@example.fi | fi | 1 |
| anna.w@example.de | DE | 7 |
| r.osei@example.gh | GH | 2 |
Only the email column changes. Addresses that were already lowercase are left as they were. The country column was unticked, so "fi" is still lowercase. A second run with UPPERCASE and only country ticked would fix it. The visits column is a number and passes through unchanged.
Working with CSV files
CSV columns are typed on load, and only columns typed as text are ticked by default. A column of codes such as 00123 or A1B2 stays text and is included. A column that holds only digits is typed as a number. It is not listed, because digits have no case, and it is copied unchanged.
Case conversion is often the step before de-duplicating or joining CSV exports from different systems, where "ACME Ltd" and "Acme Ltd" would otherwise count as two values. It changes letters only. Leading and trailing spaces are kept, so run Trim Whitespace as well if values still fail to match. The header row is not changed, only the values below it. Accented letters such as é and ñ are converted too, not just A to Z. Values already in the target case are left exactly as they were.
Title Case capitalises the first letter after each space and lowercases the rest. That suits name and city columns from CRM exports, but it does not treat hyphens or apostrophes as word breaks. "o'brien-smith" becomes "O'brien-smith", not "O'Brien-Smith", and "McDONALD" becomes "Mcdonald". Check surname columns in the preview before you download, and fix the exceptions with Find & Replace.
Frequently Asked Questions
Does converting case change the CSV header row?
No. Column names stay exactly as they were. Only the values in the ticked columns change. Use Rename Columns to change header case.
Why is a CSV column missing from the list?
Only text columns are listed. The column was read as a number, date or boolean. Cast it to text with Cast Column Types first if you need it listed.
Can I apply different cases to different columns?
Not in one run. Each run applies one case type to all ticked columns. Run the tool again on the downloaded file with the other columns ticked.
Which columns can I convert?
Text columns only, and those are the only ones listed. Number, date and boolean columns have no letters to convert, so they are left unchanged.
Does it trim spaces or fix accents?
No. It only changes letter case. Accented letters are converted correctly, for example é to É, but spaces and punctuation are left alone. Use Trim Whitespace for spaces.
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