0-RTT Connection Resumption

Zero round trip time resumption (0-RTT) improves performance for clients who have previously connected to your website.

This feature particularly benefits end users who visit your application regularly or who use mobile networks.

For more details on what 0-RTT is, how it works, and potential limitations, refer to our blog.

Availability

	Free	Pro	Business	Enterprise
Availability	Yes	Yes	Yes	Yes

Enable 0-RTT Connection Resumption

By default, 0-RTT Connection Resumption is not enabled on your Cloudflare application.

dashboard

To enable 0-RTT Connection Resumption in the dashboard:

1. Log in to your Cloudflare account and go to a specific domain.
2. Navigate to Speed > Optimization.
3. Navigate to the Protocol Optimization tab and under 0-RTT Connection Resumption, switch the toggle to On.

api

To adjust your 0-RTT Connection Resumption settings with the API, send a PATCH request with 0rtt as the setting name in the URI path, and the value parameter set to "on" or "off".

Note

The 0-RTT Connection Resumption is only established between the client and Cloudflare. It does not extend to the origin server.