CSV OPERATIONS / VALIDATE

CSV Validator

Check CSV structure before importing or converting it. Find malformed quotes, empty or duplicate headers and inconsistent records. Nothing is uploaded or automatically repaired.

How to validate a CSV file

Paste CSV or open a UTF-8 file, then choose Validate CSV. Read Valid or Invalid, review errors and copy or download the .txt report. The first non-blank record is the header. Multiline cells belong to one logical CSV record.

Input limits

Use up to 5 MB per input. Common delimiters are detected with Papa Parse, using comma as the fallback for single-column input. The report lists up to 100 errors and counts every detected error. A dash means a count could not be determined reliably.

Valid and invalid CSV examples

Valid CSV input: a multiline cell

id,name,note
001,Олена,"First line
Second line"
002,"Alex, Jr.",Ready

Valid report excerpt: 2 data records, 3 columns

CSV validation: Valid
Data rows: 2
Columns: 3
Errors found: 0
Delimiter: Comma (,)

No structural or header errors found.

Invalid CSV input: an extra field in the last record

id,name,note
001,Олена,"First line
Second line"
002,"Alex, Jr.",Ready,extra

Invalid report excerpt: CSV record 3

CSV validation: Invalid
Data rows: 2
Columns: 3
Errors found: 1
Delimiter: Comma (,)

1. CSV record 3: Found 4 fields; expected 3.

Frequently asked questions

Does Valid mean every value is suitable for my import?: Valid means no structural or header errors were found using Papa Parse syntax and CSVHarbor header rules. Header names are checked after trimming outer whitespace, with case-sensitive duplicate matching. Values, data types, formulas, dates and database constraints are not checked. Header-only CSV is valid with zero data rows. No CSV content is changed, repaired or exported.
Are error locations physical line numbers?: No. Locations are logical CSV records, including the header and blank records. Newlines inside a quoted cell do not create another record. Blank text lines are ignored for data counts; explicit empty CSV cells still count and must match the header width. Unclosed or malformed quotes can make row counts and later record locations unavailable. The validator reports that uncertainty instead of guessing.
What happens to uploaded files and previous results?: Validation runs locally on the original uploaded text, including BOM, CRLF, standalone CR and multiline cells. The textarea preview normalizes line endings; manual edits adopt that displayed text as the new input. Copy and Download export a plain-text report, never a repaired CSV. Editing or replacing CSV clears old results and disables exports until another validation. Use example loads a valid multiline CSV; Clear empties it and cancels pending uploads.