🔑 2FA Dynamic Code Generator
Tukee yksittäistä avainta ja monirivistä erätilaa · 30 sekunnin reaaliaikainen laskuri
Päivittyy automaattisesti 30 sekunnin välein
Skannaa Google Authenticatorilla tai muilla 2FA-sovelluksilla liittääksesi
Luodut eräkoodit
0 kelvollista 30sAll secret keys and generated passcodes are processed locally in your browser sandbox using the standard Web Crypto API. No data is ever transmitted to or stored on external servers.
Suositellut 2FA-tietoturvaoppaat
Korkeatasoinen kryptografinen yhteensopivuus ja tinkimätön käyttäjän yksityisyys
Google Authenticatorin siirtäminen uuteen puhelimeen
Cloud sync trade-offs, optical QR export protocols, secure old-phone wiping, offline redundancy & NTP clock drift troubleshooting.
2FA-puhelin kadonnut? Tilien palauttaminen ilman sovellusta
First 15-minute emergency response SOP, cross-platform recovery paths (Google, Microsoft, Steam, Binance, Apple) & 3-2-1 backup rules.
GitHub 2FA -käyttöönotto, tekstiviestivaravaihtoehto ja palautuskoodit
Mandatory 2FA enforcement policy, 3-tier recovery code cold storage, SSH key signature challenges & lock-out prevention strategies.
Miksi tekstiviesti-2FA on vaarallinen: SIM-swap ja SS7-hyökkäykset
SIM swap social engineering vectors, SS7 cellular interception, real-time Evilginx phishing proxies & NIST deprecation guidelines.
Kryptoturvallisuus Guide: Best 2FA Setup for Binance ja kryptopörssit
Withdrawal whitelisting, anti-phishing codes, hardware FIDO2 + TOTP hybrid architecture & cold storage for 16-character keys.
Vuoden 2026 parhaat todennussovellukset: Aegis vs 2FAS vs Bitwarden
Comprehensive side-by-side comparison of 5 leading authenticator apps: encryption models, cloud sync vs offline, and security posture.
Onko sinulla Base32-muotovirheitä tai kellonajan heittoa?
Explore our specialized 2FA Security Toolbox: Base32 Key Auto-Fixer, otpauth:// URI Inspector, and millisecond-accurate NTP clock drift detection.
2FA-menetelmien vertailu: Miksi TOTP on kultastandardi
Comparing security levels, SIM swapping resistance, cost, and availability
| Menetelmä | Turvallisuustaso | Suoja SIM-kaappaukselta | Offline-käyttömahdollisuus | Hinta | Käytettävyys | Pääasialliset käyttötarkoitukset |
|---|---|---|---|---|---|---|
| ★ TOTP (Tämä työkalu) | Korkea (Suositeltu) | Suojattu (Ei matkapuhelinverkkoa) | 100 % Offline | Ilmainen (Verkko / Sovellukset) | Erittäin korkea | Google, GitHub, AWS, Binance |
| Tekstiviestivahvistuskoodi | Matala tai keskitaso | Haavoittuva (SIM-kaappaus) | Vaatii matkapuhelinsignaalin | Matala (SIM-kortti) | Korkea | Tavanomaiset kuluttajakirjautumiset |
| Sähköpostivahvistuskoodi | Keskitaso | Riippuu sähköpostin turvallisuudesta | Vaatii internetyhteyden | Ilmainen | Keskitaso | Toissijainen varamenetelmä |
| FIDO2 / Laitteistoavaimet | Korkeaest (Anti-Phishing) | Täysin suojattu | Tuettu | 25 € - 70 € (Laitteisto) | Keskitaso (Must Carry) | Korkea-value enterprise infra |
Palveluiden määritysoppaat ja varmuuskopiointisäännöt
Miten ottaa 2FA käyttöön ja säilyttää palautusavaimet yleisimmissä palveluissa
Go to Settings -> Password and authentication -> Two-factor authentication. Click Enable 2FA, choose "Set up using an app", and copy the Base32 plaintext key.
Navigate to myaccount.google.com -> Security -> 2-Step Verification. Scroll down to "Authenticator app" and click "Can't scan it?" to copy the 32-character plaintext secret.
Under Security -> Authenticator App, click Enable. Write down the 16-character Reset Key on paper and store it in a physical safe.
Miten RFC 6238 TOTP -algoritmi toimii?
Mathematical steps turning shared secrets and Unix timestamps into synchronized codes
The Time-Based One-Time Password algorithm (TOTP) is defined in IETF RFC 6238. It converts continuous timestamps into discrete 30-second counters and executes HMAC-SHA1 hashing:
Aika-askeleen kvantisointi
Jaa nykyiset Unix-sekunnit 30 sekunnin aikavälillä: T = floor(Epoch / 30)
Base32-dekoodaus
Muunna Base32-merkkijono (RFC 4648) takaisin raaoiksi salausavaintavuiksi.
HMAC-SHA1-tiivistys
Hash the 8-byte big-endian time counter with the secret key to yield a 20-byte digest.
Dynaaminen katkaisu (Dynamic Truncation)
Use the lowest 4 bits of the last byte as an offset to extract a 31-bit unsigned integer.
Modulo 10^6
Take modulo 1,000,000: Code = Value % 10^6, zero-padded to 6 digits.
Code Shows "Invalid"? 4 Common Causes
99% of 2FA validation errors arise from local clock drift or character confusion
If your computer or phone clock drifts by even 15 seconds, your code falls into a different time window. Solution: Enable "Set Time Automatically (NTP)" in your OS settings.
Base32 contains A-Z and 2-7. It never contains 0, 1, 8, 9. Do not confuse letter O with number 0, or letter I/L with number 1.
If you clicked "Reset 2FA" on the platform multiple times, previous keys become invalid instantly. Ensure you are using the most recently generated secret.
Submitting when the progress bar has only 1-2 seconds left may cause the code to expire in transit. Wait for a fresh 30-second cycle.
Recommended Authenticator Apps
Choose the optimal 2FA client for your security workflow
Google Authenticator
Most PopularClean interface, supports Google-tili cloud backup, or can be used in offline local-only mode.
2FAS (Open Source)
Recommended100% open-source, zero data tracking. End-to-end encrypted backup to iCloud/Google Drive with browser extension pairing.
1Password / Bitwarden
ProductivityStores TOTP keys alongside passwords for seamless one-click auto-fill across all browsers and desktop apps.
Usein kysytyt kysymykset (UKK)
Detailed answers regarding 2FA security, offline operation, and batch formatting
Absolutely not. This tool operates 100% on the client side (inside your browser). All Base32 decoding and HMAC-SHA1 hash computations are performed in browser memory using the W3C standard Web Crypto API.
Your secret keys never leave your device. You can verify this using browser DevTools (F12) -> Network tab, or by running the tool in airplane mode without an internet connection.
Yes, absolutely identical. This tool strictly implements the IETF international standard RFC 6238 (TOTP).
With the same Base32 secret key and synchronized system time, it generates the exact same 6-digit codes as Google Authenticator, Microsoft Authenticator, 1Password, Bitwarden, or any other standard authenticator app.
By appending your secret key after a hash fragment like https://2fa-tool.com/fi/#JBSWY3DPEHPK3PXP, the page instantly auto-fills the key and computes codes upon opening.
Under HTTP protocol specifications, everything after the '#' symbol is evaluated solely within your local browser and is never transmitted to web servers, leaving zero server logs. However, take care not to share screen views or saved URL links with others.
Batch Mode accepts one account per line and flexibly supports raw Base32 keys, Label: SecretKey, Label, SecretKey, or standard otpauth://totp/... URIs.
You can parse dozens or hundreds of accounts concurrently and copy all generated codes in one click.
Yes, it is fully responsive. Whether you are using Safari on iPhone or Chrome on Android, you enjoy the exact same instant local Web Crypto API cryptographic calculations, interactive countdown animations, and one-tap copy functionality.
Base32 is an encoding format designed for human readability that represents binary data using only 32 characters: uppercase/lowercase letters A-Z and digits 2-7. It deliberately excludes ambiguous characters like 0, 1, O, and I to minimize transcription errors.
Our tool automatically normalizes spaces, hyphens, and padding '=' signs.
Yes. All styles, fonts, and QR rendering scripts are hosted locally on our static server.
Once the page has loaded in your browser, you can disconnect Wi-Fi or turn on Airplane Mode; the tool continues to compute dynamic TOTP codes in real time relying solely on your local device clock.
It is 100% free. No user registration, account sign-up, or personal information (such as email or phone number) is ever required. You can use it anytime with full functionality and zero restrictions.