Enable CAPTCHA Protection

Supabase provides you with the option of adding CAPTCHA to your sign-in, sign-up, and password reset forms. This keeps your website safe from bots and malicious scripts. Supabase authentication has support for hCaptcha and Cloudflare Turnstile.

Sign up for CAPTCHA

<Tabs scrollable size="small" type="underlined" defaultActiveId="hcaptcha-1" queryGroup="captcha-method"

If you have already signed up and didn't copy this information from the Welcome page, you can get the Secret key from the Settings page.

The Sitekey can be found in the Settings of the active site you created.

In the Settings page, look for the Sitekey section and copy the key.

Enable CAPTCHA protection for your Supabase project

Navigate to the Auth section of your Project Settings in the Supabase Dashboard and find the Enable CAPTCHA protection toggle under Settings > Authentication > Bot and Abuse Protection > Enable CAPTCHA protection.

Select your CAPTCHA provider from the dropdown, enter your CAPTCHA Secret key, and click Save.

Add the CAPTCHA frontend component

The frontend requires some changes to provide the CAPTCHA on-screen for the user. This example uses React and the corresponding CAPTCHA React component, but both CAPTCHA providers can be used with any JavaScript framework.

<Tabs scrollable size="small" type="underlined" defaultActiveId="hcaptcha-2" queryGroup="captcha-method"

Install @hcaptcha/react-hcaptcha in your project as a dependency.

npm install @hcaptcha/react-hcaptcha

Now import the HCaptcha component from the @hcaptcha/react-hcaptcha library.

import HCaptcha from '@hcaptcha/react-hcaptcha'

Let's create a empty state to store our captchaToken

const [captchaToken, setCaptchaToken] = useState()

Now lets add the HCaptcha component to the JSX section of our code

<HCaptcha />

We will pass it the sitekey we copied from the hCaptcha website as a property along with a onVerify property which takes a callback function. This callback function will have a token as one of its properties. Let's set the token in the state using setCaptchaToken

<HCaptcha
  sitekey="your-sitekey"
  onVerify={(token) => {
    setCaptchaToken(token)
  }}
/>

Now lets use the CAPTCHA token we receive in our Supabase signUp function.

await supabase.auth.signUp({
  email,
  password,
  options: { captchaToken },
})

We will also need to reset the CAPTCHA challenge after we have made a call to the function above.

Create a ref to use on our HCaptcha component.

const captcha = useRef()

Let's add a ref attribute on the HCaptcha component and assign the captcha constant to it.

<HCaptcha
  ref={captcha}
  sitekey="your-sitekey"
  onVerify={(token) => {
    setCaptchaToken(token)
  }}
/>

Reset the captcha after the signUp function is called using the following code:

captcha.current.resetCaptcha()

In order to test that this works locally we will need to use something like ngrok or add an entry to your hosts file. You can read more about this in the hCaptcha docs.

The frontend requires some changes to provide the CAPTCHA on-screen for the user. Turnstile can be used with any JavaScript framework but we'll use React and the Turnstile React component for this example.

Install @marsidev/react-turnstile in your project as a dependency.

npm install @marsidev/react-turnstile

Now import the Turnstile component from the @marsidev/react-turnstile library.

import { Turnstile } from '@marsidev/react-turnstile'

Let's create an empty state to store our captchaToken

const [captchaToken, setCaptchaToken] = useState()

Now lets add the Cloudflare Turnstile component to the JSX section of our code:

<Turnstile />

We will pass it the sitekey we copied from the Cloudflare website as a property along with a onSuccess property which takes a callback function. This callback function will have a token as one of its properties. Let's set the token in the state using setCaptchaToken:

<Turnstile
  siteKey="your-sitekey"
  onSuccess={(token) => {
    setCaptchaToken(token)
  }}
/>

We can now use the captchaToken we receive in our Supabase signUp function.

await supabase.auth.signUp({
  email,
  password,
  options: { captchaToken },
})

To test locally, you will need to add localhost to the domain allowlist as per the Cloudflare docs

  </TabPanel>
  </Tabs>

Run the application and you should now be provided with a CAPTCHA challenge.