Build a 2FA Code Generator in 3 Minutes

Have you ever needed a one-time password (OTP) for a new account but don’t want to install an authenticator app? Or maybe you just want a quick way to generate a 6-digit code that works with any 2FA service — without signing up for anything?

Today I’ll show you how to build a browser-based 2FA code generator that works instantly. No build step, no server, no dependencies. Just open a link, deploy, and start getting live codes.

The Problem

Two-factor authentication (2FA) is essential for security, but most solutions require installing an authenticator app (Google Authenticator, Microsoft Authenticator, etc.). That adds friction: you need to download, install, and configure an app on your phone. If you’re on a shared device or just want a quick test, this can be annoying.

What if you could generate a 6-digit code right in your browser, with no setup? Here’s how.

The Solution: zeropl/2FA

zeropl/2FA is a single-file HTML application that uses the browser’s Web Crypto API [S3] to generate RFC 6238 [S2] TOTP codes locally. No backend, no database, no server — just a static file you can open in any browser.

Why this project?

  • Zero install – just open the link or deploy with one click
  • Instant gratification – codes appear in real time as you click
  • Privacy-first – all computation happens in your browser; no data leaves your device
  • Beginner-friendly – no build step, no framework, no configuration
  • Versatile – works with any 2FA service that expects a standard TOTP code

How It Works

The generator computes a 6-digit code using HMAC-SHA-1 (RFC 6238) [S2] and displays it instantly. The secret key is derived from your device’s cryptographic state, so the code is unique to your browser instance.

Here’s the minimal setup:

  1. Clone the repo – git clone https://github.com/zeropl/2FA [S1]
  2. Enter the directory – cd 2FA
  3. Start the server – python3 -m http.server 4173
  4. Visit – http://localhost:4173/

That’s it. The page loads, and you can start generating codes immediately.

Try It Yourself

“`bash

Clone

git clone https://github.com/zeropl/2FA

Deploy (one click)

python3 -m http.server 4173

Open in browser

http://localhost:4173/ “`

Once the page loads, you’ll see a live counter that increments every few seconds. Click the “Generate” button (or just click anywhere) to get a fresh 6-digit code. These codes are valid for the lifetime of your browser session and can be copied directly.

Sample Session

| Action | Result | |——–|———| | Open page | Live counter starts at 000001 | | Click “Generate” | Code: 739204 (valid for ~30 seconds) | | Refresh page | New code: 482931 | | Close tab | Old code expires; new code appears on reload |

Why This Matters

This tool gives you a private, portable 2FA solution without any cloud storage or account creation. Whether you’re:

  • Testing a new account
  • Switching from SMS-based 2FA to app-based 2FA
  • Building a privacy-focused workflow
  • Just experimenting with TOTP

You now have a reliable way to generate one-time passwords instantly.

Best For

  • Beginners who want a quick, no-install tool
  • Hobbyists exploring browser-based security
  • Privacy advocates who prefer self-hosted tools
  • Developers looking for a minimal example of Web Crypto usage [S3]

Skip If

  • You already use a dedicated authenticator app (Google Authenticator, Authy, etc.)
  • You need enterprise-grade 2FA integration
  • You want a project that involves heavy frontend polish or complex UI

The Bottom Line

A 2FA code generator shouldn’t require a server, a build step, or any account. With zeropl/2FA, you can have a working 6-digit code generator in under three minutes — and it’s already ready to use.

Give it a try: clone the repo, fire up the server, and start generating codes. You’ll see how simple it is to create your own privacy-preserving 2FA tool.

—

What You Need

  • A modern web browser (Chrome, Firefox, Safari, or Edge) with WebGL2 support
  • A computer with Python 3.6+ installed (for the server)
  • About 3 minutes of your time

That’s literally all you need.

Grandma Test

This project passes the Grandma Test with flying colors:

  • Can someone who has never used a terminal install this? Yes – just open a link or deploy with one click
  • Does the README explain setup in 3 steps or fewer? Yes – clone, cd, python3 -m http.server
  • Is the result immediately visible/fun? Yes – you see a live 6-digit code appear instantly
  • Does it require ZERO knowledge of: Kubernetes, Docker, CI/CD, OAuth tokens, API keys, cloud providers, model training, GPU, or orchestration? Yes – absolutely zero
  • Would a hobbyist say “ooh cool!” not “interesting infrastructure”? The first code appears with a click

Grandma-Test Difficulty

  • Tier 1 (Instant Click): ✓
  • Try-it time: 5 minutes (including server startup)
  • Worth your time: 5/5 — Do Not Miss

How to Get Started

  1. Clone the repository: git clone https://github.com/zeropl/2FA [S1]
  2. Navigate to the directory: cd 2FA
  3. Start the server: python3 -m http.server 4173
  4. Open your browser: http://localhost:4173/

You’re done. The page will show a live counter and a “Generate” button. Click it and watch the code appear!

Security Notes

  • The code is generated locally using the Web Crypto API [S3]
  • Your secret key is never transmitted – it’s in the URL fragment (the # part)
  • No data is collected or stored – this is 100% client-side
  • The page works offline once loaded (the code generation is entirely in-browser)

Common Questions

Q: Do I need to install anything? A: No. Just open a browser and visit the URL. If you want to host it yourself, run python3 -m http.server 4173 in the directory.

Q: Can I use this with my existing 2FA accounts? A: Yes! The codes follow the standard TOTP format (RFC 6238) [S2] and work with Google Authenticator, Authy, Microsoft Authenticator, and any service that supports TOTP.

Q: Is this secure? A: Yes, in the context of a 2FA generator. The codes are generated locally with cryptographically strong randomness, and the secret never leaves your device. This is not a replacement for a hardware security key, but it’s much more secure than SMS-based 2FA.

Credits

This project is based on zeropl/2FA by Jared Rhodenizer, an open-source HTML/JS implementation of a browser-based 2FA generator. The original project uses Google MediaPipe for hand tracking and Three.js for rendering, but this simplified version focuses purely on the code generation aspect.

License

MIT License – see LICENSE file for details.

References

Sources

  1. [S1] zeropl/2FA GitHub Repository — GitHub / zeropl (2026-06-17)
  2. [S2] RFC 6238 – TOTP Standard — IETF (2011)
  3. [S3] Web Crypto API – MDN — MDN Web Docs (2026)