Supported Browsers

CrownSync Playbooks is a web application that runs entirely in your browser. We support the latest two major versions of the following browsers:

Google Chrome— version 120 and above
Microsoft Edge— version 120 and above (Chromium-based)
Mozilla Firefox— version 121 and above
Apple Safari— version 17 and above (macOS and iOS)

Internet Explorer is not supported. Legacy versions of Edge (non-Chromium) are not supported.

Mobile Support

The platform is fully responsive and works on mobile devices including smartphones and tablets. The mobile experience is optimised for viewing playbooks, logging incident actions, and receiving notifications. Editing playbook content and running drills are best done on a tablet or desktop for the most comfortable experience.

Supported mobile browsers include Safari on iOS 17+, Chrome on Android 14+, and Firefox on Android.

Screen Resolution

CrownSync Playbooks is designed for a minimum viewport width of 320 pixels (portrait smartphone). For the best experience when editing playbooks, managing incidents, or using the admin dashboard, we recommend a minimum resolution of 1280 × 720 pixels.

JavaScript and Cookies

JavaScript must be enabled in your browser. CrownSync Playbooks is a modern single-page application that requires JavaScript for all functionality.

Cookies must be enabled for authentication and session management. CrownSync uses essential cookies only — no third-party tracking cookies are set. See our Cookie Policy for full details.

Network Requirements

All connections to CrownSync Playbooks use HTTPS (TLS 1.2 or higher). Ensure your network allows outbound HTTPS traffic on port 443 to the following domains:

pb.crownsync.uk— the main application
auth.crownsync.uk— authentication service
analytics.crownsync.uk— privacy-respecting analytics (Plausible)

If your organisation uses a web proxy or firewall with SSL inspection, ensure the above domains are allowlisted to prevent certificate errors.

Information

CrownSync Playbooks does not require any browser extensions, plugins, or desktop software to be installed.

PDF Export Requirements

PDF exports are generated server-side and delivered as a download to your browser. There are no additional client-side requirements. Your browser must allow file downloads from pb.crownsync.uk. Generated PDFs can be opened with any standard PDF viewer including Adobe Acrobat Reader, Apple Preview, or your browser's built-in PDF viewer.

API and Webhook Requirements

If you plan to use the REST API or outbound webhooks, your receiving system must:

Accept HTTPS connections (TLS 1.2 or higher).
Be reachable from CrownSync's servers (IP allowlisting details are available on request from [email protected]).
Respond within 30 seconds for webhook deliveries. Requests that time out are retried up to three times with exponential backoff.

See the REST API Reference for full technical details.