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OTP via SMS / voice

Global coverage for one-time 2FA passcodes. Authenticate users on any mobile device or landline, anywhere.

Fast global delivery

The Authy service is built on a world class communications platform, providing reliable SMS and voice delivery around the world. Multiple long and short codes in different countries and preregistered sender IDs are used to ensure timely delivery.

Intelligent routing

Our high-quality SMS platform automatically selects the right route across our network of aggregators and carriers. We use positive feedback to replace failing routes on the fly.

Ubiquitous device support

SMS is a capability found in all mobile phones, allowing for easy user enablement because it works without internet connectivity. Voice authentication allows for landline use and is the fallback for when users have no access to an SMS enabled device.

Fast to implement

Delivered as a modern REST API, you can implement the Authy solution in a single sprint without worrying about availability, reliability or service security. We handle that for you. Just sign up and get started within minutes. Everything can be accessed immediately; we don’t hide our API behind a sales person.

"Identity is the new perimeter. Coupled with key security requirements, such as Twilio’s Authy, it can be secure, relevant, and delightful from an end user perspective."



Device-only delivery

We ensure the SMS only goes to a real handset and not to web portals, reducing the risk of compromised desktops in the authentication chain. (Note: only available in certain geographies.)

Variable code length

Authy allows you to choose a token length between 6, 7 or 8 numbers, making easy to find the right level of security for your application and increased usability where necessary.


Built in whitelisting and monitoring of numbers used for fraud helps prevent unnecessary costs and reduce fraudulent activity, saving you money.


Language support

We deliver the code or voice call in a range of languages, making it easier for the end user to understand the message they are getting. Language is automatically selected for the user based on their country code.


We can reach your users in over 200 countries and use multiple SMS carrier networks to give us the best confidence in the delivery of the codes.

Voice or SMS

To ensure full coverage of your users, you can offer either SMS or voice capabilities. This means even those in very remote locations with only a landline can still gain access to the token out of band.


Millions and billions

Authy services applications with millions of users, for customers such as Twitch, Coinbase and SendGrid. We handle billions of API calls with a solution designed to scale as you do.


We have all the information you need to start building. Get unstuck quickly with tutorials, sample code, and extensive API documentation. Plus, we provide example cURL commands and POSTMAN samples to accelerate your engineering efforts.

Helper libraries

Program in the language you already use with libraries available from Twilio and its community.

Access roles

Manage user permissions with unique access roles for admins, developers, support and billing.

Why Twilio

Build on Twilio. Code with Confidence.

Best-in-class channel APIs to keep the conversation going across all channels

Global reach and unrivaled scale that supports over

8 million developers

Powerful serverless tools and fully-programmable solutions that deploy in minutes

Enterprise-grade security and reliability, powering over 190,000 respected brands