CSV Formatter
Clean up messy CSV data — auto-detect or choose the input delimiter, trim stray whitespace, and re-serialize with a consistent delimiter and RFC 4180 quoting (quote only when needed, or always).
Input
Output
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/csv-formatter \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"csvInput": "Name, Age,City\n Alice , 30,New York\nBob,25, Bos…",
"inputDelimiter": ",",
"outputDelimiter": ",",
"quoteStyle": "as-needed",
"trimWhitespace": "true"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `csv-formatter` tool (CSV Formatter) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/csv-formatter/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="CSV Formatter — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
What does this CSV formatter do?
CSV files exported from spreadsheets, databases and scripts are rarely consistent — some use commas, others semicolons or tabs; some pad fields with stray spaces; some mix quoted and unquoted values. This tool parses whatever you paste with a real CSV parser (not a naive comma split) and re-serializes it into clean, consistently delimited, correctly quoted CSV.
RFC 4180 quoting, briefly
The RFC 4180 convention most spreadsheet and database tools follow says:
- A field only needs quoting if it contains the delimiter, a double quote, or a line break.
- A literal double quote inside a quoted field is escaped by doubling it (
""). - Everything else can be written unquoted.
This tool's parser understands that convention on the way in — a quoted field like "Smith, John" is read as one field containing a comma, not two fields — and its serializer applies it on the way out, so quoting is added only where it's actually required.
Options
- Input delimiter — comma, semicolon, tab, or Auto-detect (picks whichever delimiter appears most often, outside quotes, on the first line).
- Output delimiter — comma, semicolon, or tab, independent of the input delimiter.
- Quote style — Quote only when needed (RFC 4180 minimal quoting) or Always quote fields (wraps every field in double quotes, useful for tools that mis-parse unquoted numeric-looking strings).
- Trim whitespace — strips leading/trailing spaces from every field, useful for CSV that was hand-edited or copy-pasted from a table.
How to use it
- Paste your CSV data into the input box.
- Pick the input delimiter, or leave it on Auto-detect.
- Choose an output delimiter and quote style.
- Copy the formatted result or download it as a
.csvfile.
FAQ
Does it handle quoted fields with commas inside them correctly?
Yes. "Smith, John",30 parses as two fields — Smith, John and 30 — not three, because the parser tracks whether it's inside a quoted field before it looks for delimiters.
Can I convert a semicolon-delimited CSV to comma-delimited? Yes — set the input delimiter to semicolon (or Auto-detect) and the output delimiter to comma.
Will it fix an uneven number of columns per row? No — this tool re-delimits and re-quotes; it doesn't reshape rows. It won't silently drop or invent columns.
Privacy
Parsing and formatting run entirely in your browser. Your CSV data never leaves your device — safe for spreadsheets containing customer data, financial records, or anything else you'd rather not upload to a server.