Validate and format delimited text in your browser
Use this tool to parse and validate CSV, TSV, or TXT content in the browser. It reports parsing and structural issues, then formats issue-free data as canonical CSV or TSV. It does not repair structural problems; use CSV Cleaner for that step.
Set the parsing rules
Paste content or choose a file from the picker. The interface accepts CSV, TSV, TXT files. Set the rules to match the source:
- Input delimiter can auto-detect comma, tab, semicolon, or pipe, or use a custom one-character delimiter.
- Quote character and Escape style control quoted fields.
- Encoding selects UTF-8 or Latin-1 for reading an uploaded file.
- Output line endings selects the generated line-ending style.
- First row is a header controls header checks and expected column count.
- Include header row in export controls whether the header is written.
Validate, review, and interpret issues
Parsing and validation start automatically when content is available. Changing any parsing or output rule immediately refreshes the results.
- Parser errors, invalid quoting, and inconsistent field counts.
- Duplicate headers and missing headers.
- Mixed line endings when the file combines CRLF, LF, or CR breaks.
Most parser and structural issues identify a row. Mixed line endings are file-level issues and display - instead of one exact row. The on-page table displays up to 1,000 issues; Export issues downloads the complete issue list as csv-validation-issues.csv.
Use previews and export valid data
The regular canonical preview shows up to 200 data rows. Check Aligned preview (display only, not exported) to display all parsed data rows in padded columns. This view is for reading only.
When validation reports zero issues, click Export CSV/TSV. The export processes all parsed rows and creates UTF-8 text. CSV downloads as canonical-data.csv; TSV downloads as canonical-data.tsv. Export remains disabled while issues are present.
How to use the tool
- Paste CSV/TSV content or drop/upload a CSV, TSV, TXT file.
- Set the delimiter, quote, escape, encoding, line endings, and header options.
- Review the detected rules, statistics, preview, and reported issues.
- Fix source issues; results refresh automatically, or use CSV Cleaner for structural repair.
- Export after the issue count reaches zero.
Limitations and browser-side processing
Encoding affects how an uploaded file is read; it is not an output-encoding control. Generated CSV and TSV exports are UTF-8. Custom delimiters are reliably supported as one character. Parsing, validation, and file generation run in the browser. The regular preview is limited to 200 data rows, while aligned preview displays all parsed rows.
Frequently Asked Questions
How is this different from CSV Cleaner?
This tool only validates syntax and standardizes serialization (delimiter, quote, escape, line ending, header, and UTF-8 export). It never repairs, trims, deduplicates, or otherwise changes data. If validation finds ragged rows, invalid quoting, or other structural problems, use CSV Cleaner to repair them.
Will this tool change my data values?
No. Cell values are copied through exactly as parsed. Export standardizes the delimiter, quote character, escape style, line ending, and whether a header row is written; generated CSV and TSV files are UTF-8.
Can I export a file that has validation issues?
No. Canonical export is only enabled once the input parses cleanly with zero reported issues. This keeps the exported file a faithful, valid representation of the source data rather than a guess at a repair.
What counts as an inconsistent field count or ragged row?
A row whose number of fields does not match the expected column count - the header's column count if a header row is set, otherwise the most common row length in the file. Affected data rows are listed with their actual field count.