HTTP/2 is a much needed refresh of the HTTP protocol that was based largely on Google’s own SPDY protocol. The protocol brings with it vast improvements in communication between browsers and servers, reducing load times.
The two biggest changes are that the protocol did away with a lot of redundancy in the headers and it allows for multiplexing, or requesting multiple files at the same time. With more than 50% of websites now loading 75 or more files, according to HTTP Archive, multiplexing is a huge boon to newer websites that typically rely on more files.
TLDR; switch from HTTP/1.1 to HTTP/2. It’s easier than you think and there are no downsides. If a browser doesn’t support HTTP/2, it will simply downgrade the connection to HTTP/1.1. All you need to do to make your website support the new protocol is update your server software, assuming your server supports HTTP/2 (most do or will be adding supporting soon).
The one caveat to this is most major browsers only support the HTTP/2 protocol over a secure connection, so if your website is not already secured, then you’ll have to make the switch. Luckily for us, many hosts, CDNs, and other entities are now offering free TLS certificates which eliminates cost as a barrier to entry to security. Remember as well that HTTPS is a Google ranking factor and the switch to HTTP/2 will be better for user experience since it is faster.
Where HTTP/2 truly shines is on slower connections such as mobile networks. Without the additional round trips, the load time on slower mobile networks is reduced significantly. I would say, for most mobile networks, HTTP/2 reduces the load times more than Google AMP, but that’s not to say that you can’t use both together!
Does HTTP/2 Affect Your SEO?
John Mueller, Google Webmaster Trends Analyst, stated that Googlebot will support HTTP/2. At the time this article was written, it’s not yet confirmed that this has happened. It may have happened with all the algorithm changes in January, but there were so many, it’s difficult to tell. What’s interesting is, to my knowledge, Googlebot never supported SPDY. Google’s announcement of support for HTTP/2 shows that they will likely be adding more user experience indicators to the algorithms or, at the very least, adding HTTP/2 as a ranking signal this year. Even if there isn’t a significant boost to your rankings, remember that you are better serving your users by having a faster website.
Are SEO Companies Supporting HTTP/2?
I was surprised to find that few SEO companies seem to have added support for HTTP/2. I checked roughly 75 SEO companies whose employees routinely speak at conferences and write for various SEO blogs and could count the number of SPDY and HTTP/2 implementations on one hand. This baffles me, as so many of these companies tout better UX and increased site speed in their service offerings—but perhaps they are updating client sites and haven’t gotten around to their own yet. Even SEJ doesn’t seem to have support yet, even though they added support for HTTPS. What would happen if they did? According to my quick test from LoadImpact.com, SEJ’s load time for the homepage would decrease from 1.89 seconds to 1.25 seconds!
[Editor note: We’re aware and considering it! :)]
What Else Should SEOs Have on Their Radar?
I think that the IETF will standardize QUIC (another protocol by Google) within the next few months. The biggest advantage to this is the protocol runs on top of UDP instead of TCP. UDP master race. QUIC actually improves multiplexing. A single packet dropped in HTTP/2 can cause an overall delay, whereas the same packet dropped in QUIC will only delay one stream. This is reducing what is called head-of-line blocking. QUIC actually has 0ms round trip times for repeat connections and can establish new connections faster than HTTP/2. QUIC has some serious advantages for streaming video as well. Most people don’t realize that Google is already using QUIC on some of their services, including YouTube. YouTube users using Chrome with QUIC support were found to be 30% less likely to experience video buffering.
Giga is a replacement for TCP from Akamai which averaged a 30% speed increase. Areas of the world such as India and China had over 150% speed increases. Giga is better at determining which connections still have capacity, it’s better at determining connection paths, and also at detecting when packets are dropped and quickly sending them again.
Keep in mind that updating to HTTP/2 is as simple as updating your server software. Even if you don’t see a boost to your rankings yet, take comfort in the fact that the additional speed will be good for your users and likely your conversion rates.
Are you going to make the switch to HTTP/2?