HOTP Generator
Generate HOTP codes (counter-based) from a Base32 secret. All values are generated on your device using a cryptographically secure random generator — nothing is sent to a server.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
JBSWY3DPEHPK3PXP, counter 0
Example Output
755224 (counter 0)
How to Use
- 1Open "More settings" to adjust parameters (e.g. size/length) if needed.
- 2Click the Generate button.
- 3Copy the result with the Copy button.
About HOTP
HOTP (HMAC-based One-Time Password, RFC 4226) is the predecessor of TOTP. Instead of time, the code is computed from a counter that increments each time a code is used.
HOTP is used in hardware tokens and situations where a time clock cannot be relied on. This tool generates the code for a counter value you specify (6/8 digits, SHA1/256/512).
Because it is counter-based, the server and client must stay in sync. For the most common modern time-based 2FA, use TOTP.
FAQ
Are my data or keys sent to a server?
No. HOTP runs entirely in your browser using the Web Crypto API and client-side libraries. Your data, passwords, and keys never leave your device.