format validator

CSV Validator

Validate CSV with PapaParse, catch column mismatches, and keep data local to your browser.

Results

Processing…
Status
Processing...
Details
Processing...
Rows
Processing...
Columns
Processing...

How to use this validator

  1. Paste CSV with a header and sample rows.
  2. Run validate to parse with PapaParse and count columns.
  3. If mismatches appear, fix the flagged rows (often missing quotes or commas) and re-validate.

Rules & checks

Uses PapaParse client-side to parse CSV with standard comma delimiter and quoted fields.

Skips empty lines and trims whitespace around cells.

Checks every row for a consistent column count based on the header/first row.

Best for small-to-medium CSVs (a few thousand rows) to keep the browser responsive.

Inputs explained

  • CSV content

    Paste comma-separated text. Quote fields that contain commas or line breaks. Keep size modest for browser parsing.

When to use it

  • Preflight CSV exports before importing into CRM/BI/warehouse tools
  • Validate user-uploaded CSVs in support or admin workflows
  • Catch column drift between environments or versioned exports
  • Prep CSV before converting to JSON/NDJSON or schema validation

Common errors

  • Row has fewer/more columns than the header
  • Unterminated or stray quotes around fields
  • Unquoted commas inside values causing extra columns
  • Blank lines in the middle of data

Limitations

  • Structural check only—does not enforce data types or business rules.
  • Targets comma-delimited CSV; does not auto-detect alternative delimiters.
  • Very large files may be slow in-browser; consider chunked/server validation for multi-MB datasets.

Tips

  • Quote any field containing commas, line breaks, or quotes (escape inner quotes as "").
  • Remove blank trailing lines to avoid false mismatches.
  • Keep files small in-browser; use chunked/server-side validation for very large CSVs.
  • If you expect tabs, use a TSV validator instead.

Examples

Valid: simple table

  • name,age
  • Ada,30
  • Bob,28 -> Valid (3 rows, 2 columns)

Valid: quoted commas

  • name,notes
  • "Ada","Seattle, WA"
  • "Bob","NY, NY" -> Valid (commas preserved in quotes)

Invalid: missing column

  • name,age
  • Ada -> Invalid (row 2 has 1 column; expected 2)

Invalid: stray quote

  • name,notes
  • "Ada,"Seattle -> Invalid (unterminated quote)

Deep dive

This CSV validator uses PapaParse to spot malformed rows, stray quotes, and column mismatches before you import data.

It runs entirely client-side for privacy; keep CSVs modest in size and quote any fields that contain commas or line breaks.

FAQs

Is my CSV uploaded or stored?
No. Parsing runs in your browser only and clears on refresh.
Do you support quoted fields with commas?
Yes. PapaParse honors quoted fields; unquoted commas will increase the column count and be flagged.
Does this handle TSV?
Use the TSV validator for tab-separated files; this tool assumes commas.
Can I validate huge CSVs?
Keep it to a few thousand rows for the browser. Use chunked or server/CI validation for large datasets.
Do you validate data types?
No. This checks structure and column counts. Apply type/business rules separately.

Related validators

All CSV validation happens in your browser. No data is sent, logged, or stored.

Structure-only check; does not enforce data types or business rules.