Why this tool is useful
Use Backup Code Generator when you need a numbered set of offline backup codes without sending the source values or generated result to a server.
Generators & Random · runs locally
Backup Code Generator
Generate a numbered set of offline backup codes locally with bounded controls and cryptographically secure browser randomness.
Ready. Your working data stays in this browser.
How it works
The browser validates this tool's limits and creates separate bounded recovery strings. Rejection sampling prevents modulo bias.
Practical example
Run Backup Code Generator with the sample controls, inspect the locally generated result, then copy or download only what you intend to keep.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.