Free local preflight checker

Google Ads Offline Conversion CSV Checker

Check your offline conversion CSV before uploading it to Google Ads. Detect missing headers, invalid times, old GCLIDs, un-hashed user data, duplicates, and formatting issues locally in your browser.

Privacy: Your file is processed locally in your browser. It is not uploaded to our server.

This tool checks your CSV locally before upload. It cannot verify account-level settings, conversion action ownership, click ownership, or final attribution inside Google Ads.

Choose CSV FileCSV only · up to 10MB · processed in a browser worker when possible

Download fresh sample CSV files

These downloads are generated with relative dates so the examples stay useful over time.

Missing headers and duplicated columns

Invalid, future, date-only, or old conversion times

Plain-text email, suspicious phone, and SHA-256 hash issues

Empty click ID or user identifiers

Invalid value and currency formatting

Duplicate conversion and Order ID risks