TOTP code generator (2FA)

TOTP code generator (2FA): what it is for

Paste the Base32 secret key and see the current, previous and next TOTP codes, with the period countdown. Choose the algorithm (SHA-1, SHA-256 or SHA-512), 6 or 8 digits and a 30 or 60 second period, according to RFC 6238. The tool also generates new random keys and builds the otpauth:// link used in authenticator app QR codes.

The key never leaves your browser. Use test keys only: the secret key gives access to the account's second factor.

How to use

1. Paste the Base32 key or generate a new one.
2. Adjust algorithm, digits and period.
3. See the current code and copy the otpauth link.

When to use it

• Testing a system's 2FA implementation.
• Checking whether the server and authenticator are in sync.
• Generating keys for development environments.

Frequently asked questions

What is TOTP?

It's the time-based one-time password algorithm, defined in RFC 6238, used by authenticator apps. It computes an HMAC of the secret key with the number of 30-second periods since 1970 and turns the result into a 6-digit code.

Can I use it instead of an authenticator app?

It's not recommended. This tool is for developers testing a 2FA implementation and for checking whether a key produces the right codes. The secret key gives full access to the account's second factor, so keep real keys only in your authenticator app.

Why doesn't the code match the server's?

Check that the device's clock is right, that the algorithm (SHA-1 is the default), number of digits and period match the server settings, and that the key was copied in full, with no missing characters.

Is it really free?

Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 tools are free and run right in your browser.

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