CSV Diff Checker — Compare CSV Files Online
Paste two CSV files and instantly see every added row, removed record, and changed value. Character-level diffs included. No account. No limits.
Paste text in both panels above to compare
Or to see how it works
Compare CSV data exports
Paste two versions of a .csv export to see exactly what changed. Great for auditing database snapshots, comparing ETL pipeline output, reviewing data migrations, or spotting unexpected row changes between two report runs.
Spot changed cell values
Character-level highlighting shows the exact characters that changed within a row — not just that the row was modified. Find a single updated price, a corrected name spelling, or a changed status field without reading every column manually.
Audit data pipeline output
When a data pipeline produces different output between runs, paste both CSV results to immediately see which rows were added, removed, or changed. Faster than writing a custom comparison script for a one-off data audit.
Works for TSV and other delimiters
The diff runs on plain text, so tab-separated (TSV), pipe-delimited, or any other structured text format works just as well as standard CSV. Paste any delimiter format and the diff highlights changed rows and values the same way.
Privacy-first — runs in your browser
CSV files often contain sensitive data: customer records, financial figures, PII, and internal business metrics. DiffCheck never sends your data to any server. All comparison runs locally in JavaScript — safe for production data exports and confidential datasets.
Side-by-side and inline views
Toggle between side-by-side view (both CSV files in parallel columns) and inline view (changes interleaved with + and minus prefixes). Side-by-side is ideal for wide CSV files where you want to compare columns directly; inline works better for scanning a long list of row changes.
How to compare CSV files online
- 1
Paste your original CSV
Put the first version of your CSV file in the left editor — this is your baseline. Works with any delimiter: comma, tab, pipe, or semicolon.
- 2
Paste your modified CSV
Put the updated CSV in the right editor. For the clearest diff, make sure both files have the same column order and are sorted by the same key column.
- 3
Read the diff
Green rows were added; red rows were removed. Within changed rows, the exact characters that differ are highlighted more intensely — making it easy to spot a single changed cell value.
- 4
Switch views as needed
Use side-by-side to compare both CSVs in parallel columns, or switch to inline view for a compact change summary. The statistics bar shows total rows added, removed, and unchanged.
Frequently asked questions
What is a CSV diff checker?
A CSV diff checker compares two CSV files or datasets and highlights the differences — added rows, removed rows, and changed cell values. It is useful for auditing data exports, comparing database snapshots, reviewing ETL output, and catching data drift between pipeline runs.
Is this CSV diff tool free?
Yes, completely free with no rate limits and no signup. All CSV comparison runs in your browser — your data never leaves your device.
How should I format my CSV before comparing?
For the clearest diff, make sure both CSVs have consistent formatting — same column order, same quoting style, same line endings. The tool compares line by line, so each row becomes one diffable unit. Sorting both files by the same key column before pasting makes it easier to spot row-level changes.
Is my CSV data safe to paste here?
Yes. All diff computation runs locally in your browser using JavaScript. Your CSV data is never sent to any server, never stored, and never logged. Safe to use with customer records, financial data, database exports, or any sensitive tabular data.
Can I compare TSV (tab-separated) files?
Yes. The tool treats any plain text as diffable content, so TSV, pipe-delimited, or any other delimiter format works fine. Just paste both versions and the diff highlights exactly which rows and values changed.
What is the best way to spot a changed cell value?
Use character-level highlighting — within a changed line (row), the exact characters that differ are highlighted more intensely. This lets you spot a single value change in a row without reading every column. Switch to inline view to scan changes sequentially if you have many changed rows.