> For the complete documentation index, see [llms.txt](https://docs.cotter.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cotter.app/quickstart-guides.md).

# Quickstart Guides

- [All Guides & Tutorials](https://docs.cotter.app/quickstart-guides/all-guides-and-tutorials.md)
- [HTML – Sign in with Email/Phone](https://docs.cotter.app/quickstart-guides/html-magic-link-with-email-and-phone.md): Easily add email and phone number verification using Cotter's SDK. Send a magic link to your users via email, SMS or WhatsApp in just a few lines of code.
- [React – Sign in with Email/Phone](https://docs.cotter.app/quickstart-guides/react-magic-link-with-email-and-phone.md): Easily add email and phone number verification using Cotter's SDK. Send a magic link to your users via email, SMS or WhatsApp in just a few lines of code.
- [React – WebAuthn](https://docs.cotter.app/quickstart-guides/react-webauthn.md): Sign in users faster using WebAuthn: sign in with TouchID or Windows Hello from a web browser.
- [React Native – Sign in with Device](https://docs.cotter.app/quickstart-guides/react-native-quickstart.md): Cotter's Passwordless SDK authenticates your user based on their device. It allows a seamless, fast, and secure way for your user to login to your React Native App.
- [iOS – Sign in with Device](https://docs.cotter.app/quickstart-guides/ios-quickstart.md): Cotter's Passwordless SDK authenticates your user using the FIDO protocol. It allows a seamless, fast, and secure way for your user to login to your iOS App. Authenticate your users in 4 simple steps:
- [Flutter – Sign in with Device](https://docs.cotter.app/quickstart-guides/flutter-sign-in-with-device.md): Cotter's Passwordless SDK authenticates your user based on their device. It allows a seamless, fast, and secure way for your user to login to your React Native App.