SEOs need to have a base understanding of how the web works, which should include an understanding of HTTP2 and Service Workers. In this session Tom outlines the main things that SEOs need to understand.
11. ANATOMY OF AN HTTP/1.1 REQUEST
GET /anchorman/ HTTP/1.1
12. ANATOMY OF AN HTTP/1.1 REQUEST
GET /anchorman/ HTTP/1.1
Host: www.ronburgundy.com
13. ANATOMY OF AN HTTP/1.1 REQUEST
GET /anchorman/ HTTP/1.1
Host: www.ronburgundy.com
User-Agent: my-browser
14. ANATOMY OF A RESPONSE
HTTP/1.1 200 OK
Content-Type: text/html HEADERS
15. ANATOMY OF A RESPONSE
HTTP/1.1 200 OK
Content-Type: text/html
<html>
<head>
<title>Ron’s Page</title>
</head>
<body>
You stay classy, San Diego!
</body>
</html>
HEADERS
BODY
44. DECREASING LATENCY IMPROVES THINGS A LOT
Short roads reduce truck waiting times,
and dramatically improve load times.
source: https://hpbn.co/primer-on-web-performance/
98. CORE
NETWORK TAB IS NOT SAME AS ACTUAL NETWORK!
GET / HTTP/1.1
CACHE
GET / HTTP/1.1
BROWSER
SERVER
<html></html><html></html>
View Source &
Network Tab
show this
99. CORE
NETWORK TAB IS NOT SAME AS ACTUAL NETWORK!
GET / HTTP/1.1
CACHE
BROWSER
SERVER
<html></html>
View Source &
Network Tab
show this
Even if nothing
went over the
actual network
100. CACHED RESPONSE IN NETWORK TAB
It came from the
cache, but still we
see a ‘response’
104. CORE
IT MAY JUST PASS IT ON
CACHE
BROWSER
SERVICE
WORKER
GET / HTTP/1.1 GET / HTTP/1.1
SERVER
105. CORE
IT MAY JUST PASS IT ON
CACHE
BROWSER
SERVER
SERVICE
WORKER
GET / HTTP/1.1
GET / HTTP/1.1
<html></html>
GET / HTTP/1.1
106. CORE
IT MAY JUST PASS IT ON
CACHE
BROWSER
SERVICE
WORKER
GET / HTTP/1.1 GET / HTTP/1.1
<html></html><html></html>
SERVER
GET / HTTP/1.1
<html></html>
110. CORE
JAVASCRIPT CAN ALSO RUN AT THIS POINT
CACHE
BROWSER
SERVICE
WORKER
GET / HTTP/1.1 GET / HTTP/1.1
<html></html>
SERVER
GET / HTTP/1.1
<html></html>
112. CORE
SERVICE WORKERS CAN EDIT WHAT YOU SEE
CACHE
BROWSER
SERVICE
WORKER
GET / HTTP/1.1 GET / HTTP/1.1
<html></html><html></html>
View Source &
Network Tab
show this
SERVER
GET / HTTP/1.1
<html></html>
123. CTRL-REFRESH (F5) BYPASSES SERVICE WORKERS*
GET / HTTP/1.1
BROWSER
<html></html>
CORE CACHE
SERVICE
WORKER
<html></html>
SERVER
(* but not in View Source)
124. Googlebot (and WRS) doesn’t
use Service Workers
Not directly visible to Google,
but affects Chrome User Experience Reports data.