Symfony CAPTCHA Integration
Wire TrustCaptcha into a Symfony controller — or, even cleaner, into a custom Validator constraint — in just a few lines of PHP. Stop bot-driven spam on logins, signups and contact forms while keeping CSRF, Twig and the Form component intact. EU-hosted, GDPR-ready, no image puzzles.
Quickstart
How the integration works
1. Create a CAPTCHA
Create a user account or log in with an existing one. Then create a new CAPTCHA or select an existing one. If you’re unsure whether TrustCaptcha is right for you, try our CAPTCHA service risk-free for 14 days at no cost.
On the CAPTCHA overview page, you will find all the important information, such as the site key and licence key, and you can also create your API key. Allow your websites to access your CAPTCHA by simply adding them to the access authorised domain list in the CAPTCHA security rules.


2. Add the CAPTCHA widget to your Twig template
Drop the TrustCaptcha widget into the Twig template that renders your form. The widget runs the CAPTCHA in the background and adds a hidden tc-verification-token field on submit, which arrives on $request->request like any other input.
<script type="module" src="https://cdn.trustcomponent.com/trustcaptcha/3.0.x/trustcaptcha.esm.min.js"></script>
<form method="post" action="{{ path('contact_submit') }}">
<input type="hidden" name="_token" value="{{ csrf_token('contact') }}">
<input type="email" name="email" required>
<trustcaptcha-component sitekey="<your_site_key>"></trustcaptcha-component>
<button type="submit">Send</button>
</form>The CAPTCHA widget will then be displayed inside your form:

Need detailed information about the CAPTCHA widget integration?
For the full widget reference — including themes, languages, custom design and more — please read our documentation.
Read the documentation
3. Validate the token in your Symfony controller
In your Symfony controller, take the verification token from the request, look up the result via our PHP library, and decide whether to accept the request.
First, install our TrustCaptcha PHP library:
composer require trustcomponent/trustcaptcha-php:^3.0Then validate the token inside your controller and act on the result:
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Attribute\Route;
use TrustComponent\TrustCaptcha\TrustCaptcha;
class ContactController extends AbstractController
{
#[Route('/contact', name: 'contact_submit', methods: ['POST'])]
public function submit(Request $request): Response
{
$token = $request->request->get('tc-verification-token', '');
try {
$trustCaptcha = new TrustCaptcha('<your_api_key>');
$result = $trustCaptcha->getVerificationResult($token);
} catch (\Throwable $e) {
return $this->render('contact/index.html.twig', ['error' => 'CAPTCHA verification failed.']);
}
if (!$result->verificationPassed || $result->score > 0.5) {
return $this->render('contact/index.html.twig', ['error' => 'CAPTCHA verification failed.']);
}
// CAPTCHA passed — process the request
return $this->redirectToRoute('contact_success');
}
}Need detailed information about the Symfony CAPTCHA integration?
For full step-by-step instructions — including a reusable custom Validator constraint for projects with several protected endpoints — please read our documentation.
Read the documentation
Other backend framework instead of Symfony?
If you use a different framework, pick the matching recipe here. If your framework isn’t listed, your software developers can integrate the verification themselves using our documentation or ask our support team for a pre-built integration.
4. Congratulations 🎉
You are now protected by TrustCaptcha - congratulations!

FAQs
Where in a Symfony app does the CAPTCHA verification go?
Can I plug the CAPTCHA check into Symfony's Validator?
Does Symfony's Form component bind the widget's hidden token automatically?
Does TrustCaptcha replace Symfony's CSRF protection?
Where should I store the CAPTCHA API key?
TrustCaptcha blocks spam and bots, not customers. No puzzles, GDPR-ready, EU-hosted.


Protect your Symfony application with TrustCaptcha in just a few steps!
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