I serve up different desktop/mobile optimized html on the same URL, based on a visitor’s device type.
While Google continue to recommend the HTTP Vary: User-Agent header in these cases for mobile specific versions of the page ([youtube.com
]), I'm also aware of issues folks are raising around CDN caching; [searchengineland.com
] / [searchenginewatch.com
] / [orcaman.blogspot.com
As this is primarily for Google's benefit, it's been suggested by some infra-types that I *only* return the Vary: User-Agent header when a Google user agent is detected (Googlebot/MobileBot/AdBot).
So here's the thing: as the server header response is not “content” per se I think
this could be an okay solution, though I'd like to throw it out to the esteemed WebmasterWorld community and get some additional feedback.
You guys see any issues/problems with implementing this solution?