CSV Data Profiler
Check a CSV before importing it into another system. Find missing values, duplicate rows, unusual types and inconsistent column counts without changing the data.
1. Add CSV & choose how to read it
Markers match without case sensitivity. Values stay strings in your original file. Types are conservative guesses: leading-zero IDs and unsafe large integers remain text. Numeric ranges use JavaScript floating-point arithmetic. Limit: 5,000 rows / 100 columns / 50,000 cells / 500,000 characters.
2. Check the data quality
First 12 data rows (up to 20 columns)
Rows with inconsistent column counts
Exact duplicate rows are compared before whitespace trimming. Spreadsheet-like leading characters are counted as potential formula cells, including negative numbers. The summary CSV protects formula-like labels; no cleaned dataset is produced.
Ready. Try the example to see how it works.
Using CSV Data Profiler
Inspect the structure and common data-quality issues in a CSV before importing it.
- Paste CSV or open a UTF-8 CSV/TSV. Choose a delimiter and whether the first row contains names.
- Optionally set missing-value markers and trimming rules, then profile the table. Review uneven rows and duplicate counts.
- Read the column summary and first-row preview. Export a JSON report or a spreadsheet-protected column summary; the source is unchanged.
Example
The example includes a repeated row, a missing score and a leading-zero identifier. The identifier remains text, and duplicate rows are counted without rewriting the CSV.
Questions & answers
Does this clean or rewrite my CSV?
No. It profiles your source and produces reports. The optional trimming setting affects analysis only; original cells are not rewritten.
How are duplicate rows counted?
Each extra exact copy counts as one duplicate row. Rows are compared using the original parsed strings, before optional whitespace trimming.
Are numeric statistics exact?
Numeric ranges use JavaScript floating-point values and are approximate. Leading-zero strings and integer strings outside the safe integer range remain text. No locale-based number conversion is guessed.
What counts as a missing value?
An absent trailing cell, an empty value and any markers you explicitly provide. Markers match without case sensitivity. Whitespace counts as empty only when trimming is enabled.
Does it handle multiline CSV fields?
The existing Papa Parse library handles quoted fields, escaped quotes and embedded line breaks. Malformed quoting is rejected. Rows with different field counts are reported.
Why mention spreadsheet formulas?
Cells starting with certain characters may be interpreted as formulas by spreadsheet software. The count is a review hint, not a verdict; negative numbers can be included. Report CSV labels receive protection.
Is the dataset uploaded?
CSV parsing and profiling run in a local worker. Your file is not uploaded for processing. Site advertising and analytics follow the privacy policy.
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