EU CAPTCHA for Flutter
Flutter is Google's open-source UI toolkit for building natively compiled applications for mobile, web, and desktop from a single Dart codebase. Protect your Flutter app from bots and form spam with a privacy-first, EU-hosted CAPTCHA that's GDPR-compliant and works across Android and iOS.
Why choose Myra EU CAPTCHA?
Interaction-free user experience
No puzzles, no clicks – invisible bot protection with zero user friction.
Digital sovereignty made in Germany
Fully GDPR-compliant, no cookies, no tracking – developed and hosted in Germany.
Intelligent threat detection
Smart protection trained by more than 100 billion daily Myra CDN signals.
Proven technology
Over 5 billion successfully secured authentication attempts.
How the integration works
1. Create an EU CAPTCHA account
Creating an account is completely free, all you need is a valid email address and you’re ready to go. Choose a plan that covers your needs. The first 3 months are free of charge.
Create an Account2. Create a sitekey
Create a sitekey in the EU CAPTCHA dashboard for the domain or app identifier you want to protect. Provide a clear label so you can easily identify it later. This sitekey links the widget in your Flutter app to your EU CAPTCHA account.
3. Install the EU CAPTCHA Flutter SDK
Use the official Flutter SDK for a native integration, or add the webview_flutter package to your pubspec.yaml and load verify.js in a WebViewController manually.
View Flutter SDK4. Embed the widget in your app
Place the EU CAPTCHA widget in the screen that requires protection. The challenge runs entirely in the background — no visible puzzle or interaction is shown to the user.
5. Verify the token on your backend
Receive the eu-captcha-response token from the widget and send it to your backend API for validation against the EU CAPTCHA endpoint before processing the submission.
6. The EU CAPTCHA widget will appear in your Flutter app.
Frequently Asked Questions
What is a CAPTCHA for Flutter?
A CAPTCHA for Flutter is a bot detection mechanism embedded inside a Flutter app that distinguishes real users from automated scripts. EU CAPTCHA for Flutter runs as an invisible background verification inside a WebView widget, requiring no user interaction while protecting login forms, registration flows, and other sensitive screens.
Is there an official Flutter SDK for EU CAPTCHA?
Yes. The official EU CAPTCHA Flutter SDK is available on GitHub and provides a native integration for Flutter apps. It is the recommended approach for new Flutter projects. Alternatively, EU CAPTCHA also works using the webview_flutter package by loading the verify.js widget in a WebViewController, which requires no additional EU CAPTCHA-specific dependency.
Does EU CAPTCHA work on both Android and iOS in Flutter?
Yes. Because EU CAPTCHA runs inside a WebView using the webview_flutter package, it works on both Android and iOS from the same Dart codebase. You write the integration once and it behaves identically on both platforms, which is one of the core benefits of using Flutter for cross-platform development.
How does the JavaScript channel work for passing the CAPTCHA token?
You register a JavascriptChannel on the WebViewController with a name such as EuCaptchaChannel. When the EU CAPTCHA widget completes verification, it calls postMessage() with the eu-captcha-response token, which triggers your Dart callback. You then forward this token to your backend API for server-side validation.
Can EU CAPTCHA be used with Flutter Web?
Yes. For Flutter Web, you can load the verify.js script directly in the web/index.html file and place the widget div inside an HtmlElementView widget. The integration is simpler than the mobile approach since Flutter Web runs in a real browser environment where JavaScript interoperability is native.
Is EU CAPTCHA GDPR compliant for Flutter apps?
Yes. EU CAPTCHA is operated by an EU-based company, is hosted entirely in Germany, and does not rely on US cloud providers or infrastructure subject to US surveillance laws. The service processes only the data necessary to provide and verify the CAPTCHA (such as IP address and technical device or browser information) in line with the requirements of the GDPR. Your organization remains responsible for providing transparent privacy information, selecting an appropriate legal basis, and obtaining any required consent for your specific Flutter app implementation. This information does not constitute legal advice; please consult your legal counsel for an assessment of your individual case.
Does EU CAPTCHA affect the startup time or performance of my Flutter app?
EU CAPTCHA has negligible impact on Flutter app performance. The WebView is only loaded when the form screen that requires CAPTCHA is displayed. The verify.js script is small and the background verification runs without blocking Dart's event loop, so there is no perceptible effect on app responsiveness or startup time.
Ready for a better CAPTCHA?
Experience invisible bot protection with privacy‑first, GDPR‑compliant verification made and hosted in Germany. Try Myra EU CAPTCHA now 3 months for free and secure your web forms without adding friction for your users.
Privacy-first technology
We guarantee zero data transfer to third-country jurisdictions.
Read our privacy policyFast and easy setup
We offer ready-made integrations for many CMS and popular frameworks.
Read our quick start guide