Compare two CSV files online — without uploading them
To compare two CSV files, drop them into Diffesq: it shows changed, added, and removed cells in a grid, entirely in your browser. No upload, no account — the data never leaves your device.
How it works
- Drop a CSV file on each side of the workbench.
- Diffesq parses both locally and compares them cell by cell.
- Step through the differences with Prev/Next navigation; changes are tinted by kind.
- Export the result as an HTML, Markdown, JSON, or PDF report, generated locally.
What the comparison covers
- Cell-level comparison with added/removed/modified tinting.
- Format auto-detection (override available if a file is detected wrong).
- Local processing — safe for exports that contain customer or financial data.
Free vs Pro
Structured-file comparisons run in full on your device on the free tier, with about a third of the results shown as a preview; Pro unlocks the complete results and clean, unwatermarked exports (HTML, Markdown, JSON, PDF).
See Pricing for plans — $2.97/month, $27.99/year, or $49 once.
Privacy
Every comparison runs locally in your browser. Your files are never uploaded — there is no server that receives them, and the page keeps working with Wi-Fi turned off. Details in the Privacy Policy.
Frequently asked questions
Why not just use a text diff on CSV?
A line diff drowns you in noise when a column shifts or a row is inserted. A cell-level comparison reports the actual data change instead.
Does it work offline?
Yes — once the page has loaded, parsing, comparing, and rendering all happen on your device. Turn off Wi-Fi and it still works.
Do I need an account?
No. Comparisons run without any signup. Pro features unlock with a license key — still no account or login.