Online CSV Diff Checker
Paste two CSV files and instantly see which rows were added, removed, or changed — with individual cell highlighting for changed values.
Open the Tool — Free & InstantYour data never leaves your browser
No server processing
All diffing runs locally in your browser using JavaScript. Zero data transmitted.
No logging or storage
We do not store, log, or read your content. Nothing is saved anywhere.
Safe for sensitive content
Confidential code, config files, API keys — safe to compare here.
PII detection on share
Before any share link is generated, your content is scanned for emails, API keys, and tokens — with options to redact or encrypt.
Features
- ✓Row-by-row CSV comparison
- ✓Cell-level highlighting for changed values
- ✓Added rows highlighted green, removed rows red
- ✓Changed cells highlighted amber
- ✓Handles quoted fields and commas inside values
- ✓500KB file size limit to keep your browser fast
- ✓Drag and drop .csv files directly onto the panels
- ✓100% in-browser — CSV data never leaves your device
Frequently Asked Questions
How do I compare two CSV files online?
Paste the original CSV in the left panel and the modified CSV in the right panel. If both are valid CSVs (at least 2 rows and 2 columns), a "CSV" tab appears in the toolbar — click it to see the structured row-and-cell comparison.
Why is there a 500KB file size limit?
All processing runs in your browser. Large CSV files (thousands of rows) can take significant time and memory to diff client-side, which may slow or freeze your browser. 500KB covers the vast majority of real-world CSV comparison needs.
What if my CSV is larger than 500KB?
You can still use the text diff view by switching to Split or Unified mode — these work on any size file. The structured CSV view is only available within the 500KB limit.
Does it handle CSV files with commas inside quoted fields?
Yes. The parser handles standard CSV quoting — values enclosed in double quotes that contain commas or newlines are parsed correctly.
Is my CSV data kept private?
Completely. Your CSV is never uploaded, stored, or logged. Everything runs locally in your browser. Safe to use with confidential business data, financial records, or any sensitive spreadsheet.