Free browser-local diagnostic. Diagnose only — this page never modifies your file.
Your CSV stays in your browser. Nothing is uploaded. No analytics, cookies, tracking, or external APIs.
Choose a CSV or drop it here
.csv · processed entirely in your browser · max ~8 MB
Need repair / cleanup / export workflow?
This free tool only diagnoses. The CSV Essentials Bundle (£12) includes Duplicate Finder, Column Mapper, and Excel-Ready (BOM/encoding) as offline utilities — use them when a finding above is relevant.
Limitations: Diagnose only (no repair/export). UTF-8 focused; legacy encodings are reported but not converted here.
Quoted fields with commas/newlines are supported. Very large files may be rejected gracefully (~8 MB).
Recommendations appear only when relevant findings are present.