Decode
Your Base32 text becomes key bytes in volatile memory.
Private TOTP authenticator
Generate the code.
Keep the secret.
Your shared secret stays in this tab. 2FAOTP uses your browser's cryptographic engine to calculate the current code without an API, account, upload, advertisement, or analytics script.
Step 01
Live · local
Enter your secret
Advanced settings
Step 02
Use your code
Enter a Base32 secret to generate a code.
Waiting for secret RFC 6238
Secret stays localNever sent to a server
Nothing is storedNo cookies or browser database
Works from timeNo API required after load
What happens in this tab
Small surface.
Clear boundaries.
Calculate
Web Crypto combines the key with the current time counter.
Display
The short-lived result appears here and refreshes on schedule.
Use the right tool
A shared secret is the master key to every future code.
For everyday storage, prefer a reputable dedicated authenticator with encrypted backup. This utility cannot protect you from a compromised browser, malicious extension, infected device, screen capture, or someone watching your screen.