Skip to content
TechToolsHQ
NewsReviewsGuidesTech 101Tech SeriesToolsNewsletter
TechToolsHQ

Independent, research-driven tech coverage — breaking news, in-depth reviews, buying guides, and technical tutorials to help you understand and choose with confidence.

Explore
NewsReviewsGuidesTech 101Tech SeriesFree Tools
Legal
About UsOur AuthorsContact UsPrivacy PolicyTerms of ServiceCopyright & DMCAAffiliate DisclosureEditorial PolicyAdvertise With Us

© 2026 TechToolsHQ. All rights reserved.

Tools / 2FA / TOTP authenticator simulator

2FA / TOTP authenticator simulator

Generate live time-based one-time passwords (TOTP) from Base32 secrets or otpauth:// URIs compliant with RFC 6238. Perfect for developers testing multi-factor authentication workflows.

Runs entirely in your browser

Loading tool…

About this tool

Time-based one-time passwords (TOTP) are the six-digit codes that apps like Google Authenticator generate for two-factor authentication. They are derived from a shared secret and the current time, changing every 30 seconds, following the RFC 6238 standard. This tool simulates an authenticator: give it a Base32 secret or an otpauth:// URI and it produces the live codes with a countdown, exactly as a phone app would.

For developers, this is a practical way to test multi-factor authentication flows without juggling a physical device — you can confirm your server accepts the codes it should, debug clock-skew issues, and verify enrolment works end to end. Because the codes are standard TOTP, they interoperate with any RFC 6238 implementation.

The generation runs entirely in your browser, so the secret you paste is not transmitted. That said, a TOTP secret is a real credential: use test secrets for development, and be cautious about entering a secret tied to a live account into any web page. Treat this as a simulator and debugging aid, not a replacement for a secured authenticator app on your everyday accounts.

Frequently asked questions

What is TOTP?
Time-based One-Time Password is the standard (RFC 6238) behind six-digit two-factor codes. A code is computed from a shared secret and the current time and typically changes every 30 seconds.
What can I use this simulator for?
Testing and debugging multi-factor authentication flows: confirming your server accepts valid codes, checking enrolment, and diagnosing time-synchronisation issues — all without a separate physical device.
What input does it accept?
A Base32 TOTP secret or a full otpauth:// URI, the same values an authenticator app receives when you scan a 2FA QR code.
Is it safe to paste a real 2FA secret?
The codes are generated in your browser and the secret is not transmitted, but a live secret is a genuine credential. Prefer test secrets for development and avoid entering a secret for an important account.
Why is my generated code rejected by a service?
Most often a clock difference between systems, an incorrect secret, or a different digit count or period than the service expects. The live countdown here helps you confirm timing while you debug.

Enjoying 2FA / TOTP authenticator simulator?

TechToolsHQ is an independent, reader-supported tech platform. If this free tool saved you time, solved a problem, or helped your workflow, consider supporting our work. Your support helps us keep our utilities 100% free, private, and ad-free for everyone.

100% optional · Reader supported · Independent researchSupport our work

Related tools

  • Password generatorBuild a strong random password without it ever leaving your browser.
  • Password strength checkerEstimate how long a password survives a dictionary-and-rules attack.
  • Hash generatorSHA-1, SHA-256, SHA-384 and SHA-512 digests, computed in your browser.
  • File checksum verifierHash a downloaded file and compare it to the published value.
  • Email header analyzer & tracerDecode SPF, DKIM, DMARC authentication records and trace mail server hops.
  • Data breach & password security checkVerify credentials against public breaches using zero-knowledge k-Anonymity.

Browse all tools