CSV Lens
Explore large CSV files instantly with sorting, filtering, and column statistics. Fast, private, and secure browser-based too
Your files never leave your device. Processed locally. 100% private.
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How To Use CSV Lens
Complete your task perfectly in just three straightforward steps.
Upload CSV
Drop your CSV file — large files load instantly via virtual scrolling.
Sort and filter
Click column headers to sort. Use the filter bar to search any value.
Explore statistics
Click a column name to see distribution chart and summary stats.
FAQ
Everything you need to know about the CSV Lens.
How large a CSV can it handle?
Free plan: up to 100,000 rows. Pro: up to 5 million rows.
Can I edit data in CSV Lens?
No — CSV Lens is read-only. Use the Cleaner or Filter tool for editing.
Is my file uploaded?
No. Everything runs locally in your browser.
Can I export a filtered view?
Yes — the current filtered/sorted view can be exported as CSV.
Are charts interactive?
Yes — click bars in distribution charts to filter the table.
Can it detect duplicate rows?
Yes. CSV Lens identifies exact duplicate rows (where every column value matches) and reports the count. This is useful for validating database exports where duplicates indicate a JOIN error or an incorrect UNION query.
What format issues does it flag?
CSV Lens flags: duplicate header names (two columns with the same name), inconsistent delimiters, rows with a different number of columns than the header (jagged rows), mixed date formats within a single date column, and encoding errors. Each issue type includes the row numbers or column names affected.
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