CSVCSV Dock

Private, local-first data tools

CSV Validator and Checker

Check CSV structure in your browser, locate common row and header problems, apply reversible repairs and download a validation report.

Processed in your browserNo account requiredEncoding and delimiter controlsIncomplete exports are blocked
CSV export options
Drop a file, paste data, load a CORS-enabled URL, or try the sample.
Rows0
Columns0
EncodingAuto
DelimiterAuto
Issue groups0

Open a data file to start

The parser runs off the main thread. Once loaded, you can search, sort, validate, repair and export without an account.

What this tool does

CSV Validator and Checker

The validator checks delimiter consistency, duplicate or empty headers, inconsistent column counts, malformed quotes, invisible characters and trailing delimiters. It reports locations without sending the file anywhere.

How to use it

  1. Open the CSV and verify its detected encoding, delimiter and header setting.
  2. Review issue groups and parser messages with row or column references.
  3. Apply a reversible header or width repair, then download the report or repaired CSV.

Common tasks

  • Find rows with the wrong number of CSV columns.
  • Detect duplicate or empty headers, malformed quotes and invisible characters.
  • Check CSV encoding and delimiters before repairing or importing the file.

Privacy and local processing

Local files are read by a dedicated browser worker and are not uploaded to an application server. File contents and filenames are not included in analytics events. Loading a public URL is an explicit direct request from your browser and may fail when the remote server blocks CORS.

Supported edge cases

  • RFC-style quoting errors are reported from the parser rather than silently ignored.
  • Automatic width normalization should be reviewed because it pads or drops cells to match the header width.
  • Encoding confidence is an estimate; use the manual selector when characters look wrong.

Frequently asked questions

Does this prove a CSV follows every RFC 4180 rule?

No. CSV dialects differ in practice. The validator reports common structural problems and the detected dialect, but it does not claim universal RFC compliance.

Can repairs be undone?

Yes. Header renaming and row-width normalization keep one reversible repair step in the current browser session.

Does the validation report include my data?

No. It contains issue names, row or column references and suggested actions, not cell contents.

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