Prevent CSV formula injection in exported files

Step-by-step approach

Treat incoming CSV cells as untrusted when recipients may open them in spreadsheet software.
Look for cells that begin with =, +, -, @, tab or carriage return.
Run the CSV Formula Injection Checker for suspect entries.
Export using formula-safe escaping and verify how your spreadsheet application interprets the file.
Do not assume CSV quoting alone neutralizes spreadsheet formulas in all applications.

Try the matching tool

Open Formula Injection Checker to work on a local copy. Review the result before importing it elsewhere.

What this does not solve

Browser tools can validate known structures and transform available data, but cannot restore deleted or corrupted bytes, infer unknown business facts, or guarantee that a target system will import every field as intended.