User-Agent Reduction 📖 Deprecation Origin Trial

This demo demonstrates the User-Agent request header containing the desired (either reduced or full) user agent string in the presence of a valid UA Reduction 📖 Deprecation Origin Trial token for all subsequent requests to the site.

[Request] Request User-Agent:

CCBot/2.0 (

[Response] Server asked for:


[Subsequent Request] Client sent:


[For comparison] Subsequent Request User-Agent:


Server opt-in origin trials:

What are those origin trials?
Available Origin Trials
What's the difference for Critical-CH? When Critical-CH in the header, the first navigation will also send the desired (either reduced or full) user-agent string in the User-Agent request header.