---
title: Two-Factor Authentication (2FA)
description: Enhance your app's security with two-factor authentication.
---

`OTP` `TOTP` `Backup Codes` `Trusted Devices`

Two-Factor Authentication (2FA) adds an extra security step when users log in. Instead of just using a password, they'll need to provide a second form of verification. This makes it much harder for unauthorized people to access accounts, even if they've somehow gotten the password.

This plugin offers two main methods to do a second factor verification:

1. **OTP (One-Time Password)**: A temporary code sent to the user's email or phone.
2. **TOTP (Time-based One-Time Password)**: A code generated by an app on the user's device.

**Additional features include:**
- Generating backup codes for account recovery
- Enabling/disabling 2FA
- Managing trusted devices

## Installation

<Steps>
    <Step>
        ### Add the plugin to your auth config

        Add the two-factor plugin to your auth configuration and specify your app name as the issuer.

        ```ts title="auth.ts"
        import { betterAuth } from "better-auth"
        import { twoFactor } from "better-auth/plugins" // [!code highlight]

        export const auth = betterAuth({
            // ... other config options
            appName: "My App", // provide your app name. It'll be used as an issuer. // [!code highlight]
            plugins: [
                twoFactor() // [!code highlight]
            ]
        })
        ```
    </Step>
      <Step>
        ### Migrate the database

        Run the migration or generate the schema to add the necessary fields and tables to the database.

        <Tabs items={["migrate", "generate"]}>
            <Tab value="migrate">
            ```bash
            npx @better-auth/cli migrate
            ```
            </Tab>
            <Tab value="generate">
            ```bash
            npx @better-auth/cli generate
            ```
            </Tab>
        </Tabs>
        See the [Schema](#schema) section to add the fields manually.
    </Step>

        <Step>
        ### Add the client plugin

        Add the client plugin and Specify where the user should be redirected if they need to verify 2nd factor

        ```ts title="auth-client.ts"
        import { createAuthClient } from "better-auth/client"
        import { twoFactorClient } from "better-auth/client/plugins"

        const authClient = createAuthClient({
            plugins: [
                twoFactorClient()
            ]
        })
        ```
        </Step>
</Steps>

## Usage

### Enabling 2FA

To enable two-factor authentication, call `twoFactor.enable` with the user's password:

```ts title="two-factor.ts"
const { data } = await authClient.twoFactor.enable({
    password: "password" // user password required
})
```

When 2FA is enabled:
- An encrypted `secret` and `backupCodes` are generated.
- `enable` returns `totpURI` and `backupCodes`.

Note: `twoFactorEnabled` won’t be set to `true` until the user verifies their TOTP code.

To verify, display the QR code for the user to scan with their authenticator app. After they enter the code, call `verifyTotp`:

```ts
await authClient.twoFactor.verifyTotp({
    code: "" // user input
})
```

<Callout>
You can skip verification by setting `skipVerificationOnEnable` to true in your plugin config.
</Callout>

### Sign In with 2FA

When a user with 2FA enabled tries to sign in via email, the response will contain `twoFactorRedirect` set to `true`. This indicates that the user needs to verify their 2FA code.

```ts title="sign-in.ts"
await authClient.signIn.email({
    email: "user@example.com",
    password: "password123",
})
```

You can handle this in the `onSuccess` callback or by providing a `onTwoFactorRedirect` callback in the plugin config.

```ts title="sign-in.ts"
import { createAuthClient } from "better-auth/client";
import { twoFactorClient } from "better-auth/client/plugins";

const authClient = createAuthClient({
    plugins: [twoFactorClient({
        onTwoFactorRedirect(){
            // Handle the 2FA verification globally
        }
    })]
})
```

Or you can handle it in place:

```ts
await authClient.signIn.email({
        email: "user@example.com",
        password: "password123",
    }, {
        async onSuccess(context) {
            if (context.data.twoFactorRedirect) {
                // Handle the 2FA verification in place
            }
        }
    }
})
```

#### Using `auth.api`

When you call `auth.api.signInEmail` on the server, and the user has 2FA enabled, it will, by default, respond with an object where `twoFactorRedirect` is set to `true`. This behavior isn’t inferred in TypeScript, which can be misleading. We recommend passing `asResponse: true` to receive the Response object instead.

```ts
const response = await auth.api.signInEmail({
    email: "my-email@email.com",
    password: "secure-password",
    asResponse: true
})
```

### TOTP

TOTP (Time-Based One-Time Password) is an algorithm that generates a unique password for each login attempt using time as a counter. Every fixed interval (Better Auth defaults to 30 seconds), a new password is generated. This addresses several issues with traditional passwords: they can be forgotten, stolen, or guessed. OTPs solve some of these problems, but their delivery via SMS or email can be unreliable (or even risky, considering it opens new attack vectors).

TOTP, however, generates codes offline, making it both secure and convenient. You just need an authenticator app on your phone, and you’re set—no internet required.

#### Getting TOTP URI

After enabling 2FA, you can get the TOTP URI to display to the user. This URI is generated by the server using the `secret` and `issuer` and can be used to generate a QR code for the user to scan with their authenticator app.

```ts
const { data, error } = await authClient.twoFactor.getTotpUri({
    password: "password" // user password required
})
```

**Example: Using React**

```tsx title="user-card.tsx"
import QRCode from "react-qr-code";

export default function UserCard(){
    const { data: session } = client.useSession();
	const { data: qr } = useQuery({
		queryKey: ["two-factor-qr"],
		queryFn: async () => {
			const res = await authClient.twoFactor.getTotpUri();
			return res.data;
		},
		enabled: !!session?.user.twoFactorEnabled,
	});
    return (
        <QRCode value={qr?.totpURI || ""} />
   )
}
```

<Callout>
By default the issuer for TOTP is set to the app name provided in the auth config or if not provided it will be set to `Better Auth`. You can override this by passing `issuer` to the plugin config.
</Callout>

#### Verifying TOTP

After the user has entered their 2FA code, you can verify it using `twoFactor.verifyTotp` method.

```ts
const verifyTotp = async (code: string) => {
    const { data, error } = await authClient.twoFactor.verifyTotp({ code })
}
```

### OTP

OTP (One-Time Password) is similar to TOTP but a random code is generated and sent to the user's email or phone.

Before using OTP to verify the second factor, you need to configure `sendOTP` in your Better Auth instance. This function is responsible for sending the OTP to the user's email, phone, or any other method supported by your application.

```ts title="auth.ts"
import { betterAuth } from "better-auth"
import { twoFactor } from "better-auth/plugins"

export const auth = betterAuth({
    plugins: [
        twoFactor({
          	otpOptions: {
				async sendOTP({ user, otp }, request) {
                    // send otp to user
				},
			},
        })
    ]
})
```

#### Sending OTP

Sending an OTP is done by calling the `twoFactor.sendOtp` function. This function will trigger your sendOTP implementation that you provided in the Better Auth configuration.

```ts
const { data, error } = await authClient.twoFactor.sendOtp()
if (data) {
    // redirect or show the user to enter the code
}
```

#### Verifying OTP

After the user has entered their OTP code, you can verify it

```ts
const verifyOtp = async (code: string) => {
    await authClient.twoFactor.verifyOtp({ code }, {
        onSuccess(){
            //redirect the user on success
        },
        onError(ctx){
            alert(ctx.error.message)
        }
    })
}
```

### Backup Codes

Backup codes are generated and stored in the database. This can be used to recover access to the account if the user loses access to their phone or email.

#### Generating Backup Codes
Generate backup codes for account recovery:

```ts
const { data, error } = await authClient.twoFactor.generateBackupCodes({
    password: "password" // user password required
})
if (data) {
    // Show the backup codes to the user
}
```

#### Using Backup Codes

You can now allow users to provider backup code as account recover method.

```ts
await authClient.twoFactor.verifyBackupCode({code: ""}, {
    onSuccess(){
        //redirect the user on success
    },
    onError(ctx){
        alert(ctx.error.message)
    }
})
```

once a backup code is used, it will be removed from the database and can't be used again.

#### Viewing Backup Codes

You can view the backup codes at any time by calling `viewBackupCodes`. This action can only be performed on the server using `auth.api`.

```ts
await auth.api.viewBackupCodes({
    body: {
        userId: "user-id"
    }
})
```

### Trusted Devices

You can mark a device as trusted by passing `trustDevice` to `verifyTotp` or `verifyOtp`.

```ts
const verify2FA = async (code: string) => {
    const { data, error } = await authClient.twoFactor.verifyTotp({
        code,
        callbackURL: "/dashboard",
        trustDevice: true // Mark this device as trusted
    })
    if (data) {
        // 2FA verified and device trusted
    }
}
```

When `trustDevice` is set to `true`, the current device will be remembered for 60 days. During this period, the user won't be prompted for 2FA on subsequent sign-ins from this device. The trust period is refreshed each time the user signs in successfully.

### Issuer

By adding an `issuer` you can set your application name for the 2fa application.

For example, if your user uses Google Auth, the default appName will show up as `Better-Auth`. However, by using the following code, it will show up as `my-app-name`.

```ts
twoFactor({
    issuer: "my-app-name" // [!code highlight]
})
```
---

## Schema

The plugin requires 1 additional fields in the `user` table and 1 additional table to store the two factor authentication data.

<DatabaseTable
    fields={[
        { name: "twoFactorEnabled", type: "boolean", description: "Whether two factor authentication is enabled for the user.", isOptional: true },
    ]}
/>

Table: `twoFactor`

<DatabaseTable
    fields={[
        { name: "secret", type: "string", description: "The secret used to generate the TOTP code.", isOptional: true },
        { name: "backupCodes", type: "string", description: "The backup codes used to recover access to the account if the user loses access to their phone or email.", isOptional: true },
    ]}
/>

## Options

### Server

**twoFactorTable**: The name of the table that stores the two factor authentication data. Default: `twoFactor`.

**skipVerificationOnEnable**: Skip the verification process before enabling two factor for a user.

**Issuer**: The issuer is the name of your application. It's used to generate TOTP codes. It'll be displayed in the authenticator apps.

**TOTP options**

these are options for TOTP.

<TypeTable
  type={{
    digits:{
        description: "The number of digits the otp to be",
        type: "number",
        default: 6,
    },
    period: {
        description: "The period for otp in seconds.",
        type: "number",
        default: 30,
    },
  }}
/>

**OTP options**

these are options for OTP.

<TypeTable
  type={{
    sendOTP: {
        description: "a function that sends the otp to the user's email or phone number. It takes two parameters: user and otp",
        type: "function",
    },
    period: {
        description: "The period for otp in seconds.", 
        type: "number",
        default: 30,
    },
  }}
  />

**Backup Code Options**

backup codes are generated and stored in the database when the user enabled two factor authentication. This can be used to recover access to the account if the user loses access to their phone or email.

<TypeTable
    type={{
        amount: {
            description: "The amount of backup codes to generate",
            type: "number",
            default: 10,
        },
        length: {
            description: "The length of the backup codes",
            type: "number",
            default: 10,
        },
        customBackupCodesGenerate: {
            description: "A function that generates custom backup codes. It takes no parameters and returns an array of strings.",
            type: "function",
        },
    }}
/>

### Client

To use the two factor plugin in the client, you need to add it on your plugins list.

```ts title="auth-client.ts"
import { createAuthClient } from "better-auth/client"
import { twoFactorClient } from "better-auth/client/plugins"

const authClient =  createAuthClient({
    plugins: [
        twoFactorClient({ // [!code highlight]
            onTwoFactorRedirect(){
                window.location.href = "/2fa" // Handle the 2FA verification redirect
            }
        }) // [!code highlight]
    ]
})
```


**Options**

`onTwoFactorRedirect`: A callback that will be called when the user needs to verify their 2FA code. This can be used to redirect the user to the 2FA page.
