Twilio Authy

YES

Replaceable in one session with an AI coding agent.

A two-factor authentication app that holds your one-time-code seeds and backs them up encrypted, so moving to a new phone does not lock you out of everything.

Promptfree, for everyone, and the only version there is

Build a TOTP authenticator, and take the backup seriously.

STACK
- An installable web app, IndexedDB, the Web Crypto API — no server

THE ALGORITHM
- TOTP as specified in RFC 6238: HMAC-SHA1 over the counter, 30-second step, 6 digits
- Use Web Crypto for the HMAC; do not write the primitive yourself
- Accept otpauth:// URIs, from a QR scanned in the browser or pasted as text

STORING SEEDS
- Encrypted at rest with a key derived from a passphrase through PBKDF2 or Argon2
- Never in plain localStorage, and never sent anywhere

THE SCREEN
- One row per account with the current code and a ring showing time remaining
- Tap to copy; codes never appear in a URL or in a log

BACKUP, WHICH IS WHERE PEOPLE GET HURT
- Export as an encrypted file with a passphrase
- Warn on first run that losing the passphrase means losing every code, and make the user acknowledge it
- Test a restore into a fresh browser profile before you rely on it

Include the TOTP implementation, the key derivation and the export format.

What you lose

Encrypted multi-device backup, which is the reason people choose this over a plain authenticator
Apps on phone and desktop that stay in step
A recovery path when the phone is lost, which is the whole point of the category

If you would rather not build

A password manager with TOTP built in

The escape hatch

open source · no votes, no paid placement

Aegis Authenticator

Android TOTP app with an encrypted vault and a real export.

beemdevelopment/Aegisfree · open source

Ente Auth

Open-source authenticator with end-to-end encrypted sync across devices.

ente/entefree · open source

Why this verdict

our own opinion · changed only by a person

80/100

Verdict yes at 80: TOTP is a documented algorithm and Web Crypto does the hard part. The backup and its warning are what separate a usable authenticator from a way to lose your accounts.

History

tracked since 10 Aug 2026 · nothing is ever overwritten

Interest · last 30 days

Nothing recorded yet. This chart fills in once the page has visitors, votes or prompt copies — it will not draw a flat line to look busy.

Questions about Twilio Authy

answered from the record above

Is Twilio Authy free?

No — the plan we track is $0 a month. Free for personal use; the paid product is the Verify API sold to developers per verification.

Can you replace Twilio Authy by building your own?

YES. Replaceable in one session with an AI coding agent. Replacement score 80 out of 100, build time one session. Read what you lose before you decide.

How much does Twilio Authy cost?

$0 a month on Free — $0 a year. Recorded 10 Aug 2026.

What do you lose by replacing Twilio Authy?

Encrypted multi-device backup, which is the reason people choose this over a plain authenticator; Apps on phone and desktop that stay in step; A recovery path when the phone is lost, which is the whole point of the category. If any of those carry weight for you, keep paying.

Is there an open-source alternative to Twilio Authy?

Yes: Aegis Authenticator, Ente Auth. The prompt on this page is for when you want it your way instead.

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