OTP Generator — Free Online TOTP Code Generator & 2FA Validator

OTP Generator — Free Online TOTP Code Generator & 2FA Validator. Free online OTP generator for time-based TOTP codes (RFC 6238). Generate one-time passwords, validate 2FA codes, and test your authenticator setup — 100% private, runs in browser.

Generate and validate time-based one-time passwords instantly with our free OTP generator . Enter any Base32 secret key and get your current, previous, and next TOTP code in real time — with a live countdown showing exactly when the code refreshes.

Built on the same RFC 6238 algorithm used by Google Authenticator, Authy, and every major 2FA app.

Use the built-in OTP validator to check whether a specific code is valid for your secret, making it perfect for debugging authenticator apps, testing login flows, and verifying QR code setups.

All cryptographic calculations run entirely in your browser — your secret keys never leave your device. Why use an online TOTP code generator?

When setting up two-factor authentication for a new service, you need to confirm that your secret key is correct before locking yourself into an authenticator app.

Our 2FA code generator lets you instantly verify that a seed produces the right codes, confirm that your server-side OTP validation matches, or debug timing issues with the epoch display and iteration counter.

The QR code output lets you scan the secret directly into any authenticator app for quick testing. Need to hash authentication tokens? Our JWT Parser handles token debugging, and the HMAC Generator covers the underlying cryptography.

FAQ

How do I generate a TOTP code from a secret key?

Paste the Base32 secret (letters A to Z and digits 2 to 7, shown when you set up 2FA) into the Secret field. The Current OTP is displayed in the middle with the Previous and Next codes beside it; click any code to copy it.

How do I verify a 2FA code with the OTP validator?

Type the 6-digit code into Verify a code. It shows Valid if the code matches the current, previous or next 30-second window, which tolerates small clock differences, and Invalid otherwise.

Which OTP settings does the generator use?

It generates time-based codes (TOTP, RFC 6238) with HMAC-SHA1, 6 digits and a 30-second period, the defaults used by Google Authenticator, Microsoft Authenticator and most services. Other algorithms, code lengths, periods and counter-based HOTP codes cannot be configured.

Why does it say Secret should be a base32 string?

The secret may only contain the letters A to Z and the digits 2 to 7; lowercase letters are accepted. Remove any spaces, dashes or = padding that a site used to format the key.

What are the QR code and Open Key URI button for?

They encode the secret as an otpauth URI (issuer TimeToTime, account demo-user). Scanning the QR code with an authenticator app adds a test entry, so you can confirm the app and this page produce the same codes. The refresh icon in the Secret field creates a new random 16-character secret.

Is my secret sent anywhere?

No. Codes are computed in your browser and the secret is not uploaded. A TOTP secret is as sensitive as a password, though, so avoid pasting real production secrets on shared or untrusted devices.

How to use this online tool

OTP Generator — Free Online TOTP Code Generator & 2FA Validator is designed for fast browser workflows when you need to format, validate, convert, decode, encode, generate, or inspect data without opening a heavy desktop app. Start with the input field or visible options, review the result, then copy or download the output for the next step.

Private processing in your browser

OTP Generator — Free Online TOTP Code Generator & 2FA Validator keeps the normal processing step local in your browser. That is useful for code snippets, tokens, documents, configuration values, text samples, and other material that should not be sent to a remote service unless you explicitly choose to share it.

When this tool is useful

Use OTP Generator — Free Online TOTP Code Generator & 2FA Validator for repeatable developer tasks, technical documentation, QA checks, quick conversions, debugging, content cleanup, and internal team workflows. The page focuses on clear inputs, immediate feedback, and output that is easy to reuse in code, reports, tickets, emails, or notes.

Practical tips

Before copying the final result, check important details such as spacing, casing, filenames, encoding, token structure, line breaks, or output format. Small checks prevent mistakes when the result is reused in source code, API requests, documentation, spreadsheets, or shared files.