Pitfalls when implementing the “VARY User-Agent” server response
-
We 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 for mobile specific versions of the page (http://www.youtube.com/watch?v=va6qtaiZRHg), we’re also aware of issues raised around CDN caching; http://searchengineland.com/mobile-site-configuration-the-varies-header-for-enterprise-seo-163004 / http://searchenginewatch.com/article/2249533/How-Googles-Mobile-Best-Practices-Can-Slow-Your-Site-Down / http://orcaman.blogspot.com/2013/08/cdn-caching-problems-vary-user-agent.html
As this is primarily for Google's benefit, it's been proposed that we only returning 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 wanted to throw it out there to the esteemed Moz community and get some additional feedback.
You guys see any issues/problems with implementing this solution?
Cheers!
linklater
-
So, there are lots of 'ifs' here, but the primary problem I see with your plan is that the CDN will return the content to Googlebot without the request hitting your server so you won't have the option to serve different headers to Googlebot.
Remember that every page is the main HTML content (which may be static or dynamically generated for every request), and then a whole bunch of other resources (Javascript and CSS files, images, font files etc.). These other resources are typically static and lend themselves far better to being cached.
Are your pages static or dynamic? If they are dynamic then you are possibly not benefitting from them being cached anyway, so you could use the 'vary' header on just these pages, and not on any static resources. This would ensure your static resources are cached by your CDN and give you a lot of the benefit of the CDN, and only the dynamic HTML content is served directly from the server.
If most of your pages are static you could still use this approach, but just without the full benefit of the CDN, which sucks.
Some of the CDNs are already working on this (see http://www.computerworld.com/s/article/9225343/Akamai_eyes_acceleration_boost_for_mobile_content and http://orcaman.blogspot.co.uk/2013/08/cdn-caching-problems-vary-user-agent.html) to try and find better solutions.
I hope some of this helps!
Got a burning SEO question?
Subscribe to Moz Pro to gain full access to Q&A, answer questions, and ask your own.
Browse Questions
Explore more categories
-
Moz Tools
Chat with the community about the Moz tools.
-
SEO Tactics
Discuss the SEO process with fellow marketers
-
Community
Discuss industry events, jobs, and news!
-
Digital Marketing
Chat about tactics outside of SEO
-
Research & Trends
Dive into research and trends in the search industry.
-
Support
Connect on product support and feature requests.
Related Questions
-
How to answer a question matching user intent ?
Hello, How do you answer questions (the famous user intent) in your content when moz keyword tool, google related searches or all the other tools on the market don't have any questions to propose ? For example take the keyword title tag, the questions are, the optimal length, title tag definition etc... But what about with the keyword Provence bike tours ? what are the questions people have ? It is an informational query but I can't find any questions for it with the different tools out there ? The only one that I find are "best base for a bike tour in Provence" or "one day bicycle tour in Provence" but this isn't what I offer or do and it will be very hard to integrate in my content other than I do a blog page that answer those questions... Is there a way to answer for example "biking in Provence" which is a keyword the keyword tool gives me ? Thank you,
Intermediate & Advanced SEO | | seoanalytics1 -
IP Address location v Server Location Penguin 4/Possum
Hi All, Our hosting provider have their IP address range in Melbourne but offers servers in Sydney or Melbourne.. If we were to take a server in Sydney and an IP address from their Melbourne range (only IP range offered) will the new localisation updates to the Penguin/Possum Algorithms serve less up to our clients in Sydney thinking we are located in Melbourne? Sorry if im confusing.. I know I am 🙂
Intermediate & Advanced SEO | | CFCU1 -
Redirect at Registrar or Server
Hi folks, I have run into a situation were a new client has 3 TLDs (e.g. mycompany.com, mycompany.org and mycompany.biz), all with the same content. They are on a Windows IIS environment, which I am not familiar with. Until now, all of my clients have been Linux/Apache environment, so I always dealt with these issues utilizing htaccess. Currently all resolve to the same IP, but the URL remains the same in the browser address field (e.g. if you type-in mycompany.org - it remains as such). We want the .org and .biz version to 301 Redirect to the .com TLD. I am wondering what the best practice might be in this situation? Could we simply redirect at the registrar level or would implementation at the server level be best? If so, I would really appreciate an example from someone with experience implementing redirects on IIS. Thank you!
Intermediate & Advanced SEO | | SCW0 -
Best way to implement canonical tags on an ecommerce site with many filter options?
What would be the best way to add canonical tags to an ecommerce site with many filter options, for example, http://teacherexpress.scholastic.com? Should I include a canonical tag for all filter options under a category even though the pages don't have the same content? Thanks for reading!
Intermediate & Advanced SEO | | DA20130 -
Benefits of Implementing Open Graph?
I understand the benefits of implementing Open Graph as a local business, but am unclear of the benefits for a website, for example, a health website. Does Bing use OG in their search algorithm?
Intermediate & Advanced SEO | | nicole.healthline0 -
Is my schema implemented correctly and not spammy?
i already used the validation tool from Google. It tell's me it's implemented, but i would like to know specifically if everything is implemented correctly and in a non spam way. Here is a product link to test: http://www.suddora.com/pink-sweatbands-wholesale-pink-wristbands.html
Intermediate & Advanced SEO | | Hyrule1 -
Is User Agent Detection still a valid method for blocking certain URL parameters from the Search Engines?
I'm concerned with the cloaking issue. Has anyone successfully implemented user agent detection to provide the Search engines with "clean" URLs?
Intermediate & Advanced SEO | | MyaRiemer0