> 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/sdk-reference/web.md).

# Web

## Complete Guides

#### Sign in with Email/Phone Number

Authenticate users by sending a Magic Link or OTP via email, SMS, or WhatsApp

{% content-ref url="/pages/-M0ROJn7tosL9qeumqFd" %}
[Sign In with Email/Phone Number](/sdk-reference/web/web-sdk-verify-email-phone.md)
{% endcontent-ref %}

#### Sign in with WebAuthn

Authenticate users using TouchID or Windows Hello from your website.

{% content-ref url="/pages/-MCk3X5Dh4Fkxp20D4Rt" %}
[Sign In with WebAuthn](/sdk-reference/web/sign-in-with-webauthn.md)
{% endcontent-ref %}

#### Sign in with Device

If you have **mobile app**, you can ask the user to approve the login request from their phone.

{% content-ref url="/pages/-M3o-GTINgCweb4ATz-9" %}
[Sign In with Device](/sdk-reference/web/web-sdk-passwordless-login.md)
{% endcontent-ref %}

## Quickstart Guides

{% content-ref url="/pages/-MBpqtdlR54h41rVFGWy" %}
[React – Sign in with Email/Phone](/quickstart-guides/react-magic-link-with-email-and-phone.md)
{% endcontent-ref %}

{% content-ref url="/pages/-MAUbWpO8XONhF-vdxAG" %}
[HTML – Sign in with Email/Phone](/quickstart-guides/html-magic-link-with-email-and-phone.md)
{% endcontent-ref %}

{% content-ref url="/pages/-MCjwlfkbi3ejQQ0qQ4K" %}
[React – WebAuthn](/quickstart-guides/react-webauthn.md)
{% endcontent-ref %}