How Keylo works: your online 2FA code generator

Keylo is a free, browser-based 2FA code generator. Paste your secret key and it turns it into the same six-digit code your login screen is asking for — no app to install, nothing sent to a server.

What is a 2FA code generator?

A 2FA (two-factor authentication) code generator turns a one-time setup key into the rotating six-digit codes you type in after your password. When a website offers "authenticator app" 2FA, it hands you a secret key; an authenticator code generator like Keylo uses that key to produce a fresh code every 30 seconds. Because the math is standardized, an online 2FA code generator produces exactly the same codes as Google Authenticator, Authy, or 1Password for the same key.

How do I generate a 2FA code from a secret key?

To generate a 2FA code from a secret key with Keylo:

1. Open the Keylo home page.
2. Paste your Base32 secret key into the input box. Spaces and dashes are fine — Keylo cleans them up for you.
3. Your six-digit code appears immediately, along with a timer showing how long it stays valid.
4. Tap the code or the Copy button, then paste it into the site asking for your 2FA code.

The code refreshes automatically every 30 seconds, so if it is about to expire, just wait for the next one.

Where do I find my 2FA setup key?

Your setup key comes from the service you are securing — for example your email, bank, or social account — inside its "Security" or "Two-factor authentication" settings. When you choose "Set up authenticator app," most sites show a QR code plus a line of letters and numbers usually labelled "secret key," "setup key," or "manual entry code." That string is what you paste into a TOTP generator. If you only see a QR code, look for a "Can't scan?" or "Enter code manually" link to reveal the text version.

Save that key somewhere safe when you first set it up. Anyone with the key can generate your codes, so treat it like a password.

What is a TOTP code?

TOTP stands for Time-based One-Time Password. A TOTP code is the six-digit number a 2FA generator creates by combining your secret key with the current time, following the open standard RFC 6238. Because both your device and the server use the same key and the same clock, they independently arrive at the same code — which is why a TOTP generator works offline and never needs to talk to the website. Keylo produces standard 6-digit, 30-second, SHA-1 TOTP codes, the format nearly every service uses.

Why is my 2FA code not working?

If a code is rejected, check these common causes:

• Clock drift. TOTP depends on accurate time. If your device clock is off by more than a few seconds, codes won't match. Turn on automatic date and time.
• Expired code. Each code is only valid for about 30 seconds. If the timer is nearly empty, wait for the next one.
• Wrong or mistyped key. A single wrong character produces valid-looking but incorrect codes. Re-copy the secret key exactly.
• Wrong account. Make sure the key you pasted belongs to the account you are actually logging into.

Does Keylo send my key to a server?

Keylo generates your code inside your browser and does not send your key to a code-generation service. The key is only kept on your own device so you don't have to paste it every time, and the "Forget key" button clears it whenever you want. You can even save the page and run this authenticator code generator fully offline.