HTTP vs HTTPS performance

Question

Are there any major differences in performance between http and https? I seem to recall reading that HTTPS can be a fifth as fast as HTTP. Is this valid with the current g

Answer 1

Browsers can accept HTTP/1.1 protocol with either HTTP or HTTPS, yet browsers can only handle HTTP/2.0 protocol with HTTPS. The protocol differences from HTTP/1.1 to HTTP/2.0 make HTTP/2.0, on average, 4-5 times faster than HTTP/1.1. Also, of sites that implement HTTPS, most do so over the HTTP/2.0 protocol. Therefore, HTTPS is almost always going to be faster than HTTP simply due to the different protocol it generally uses. However, if HTTP over HTTP/1.1 is compared with HTTPS over HTTP/1.1, then HTTP is slightly faster, on average, than HTTPS.

Here are some comparisons I ran using Chrome (Ver. 64):

HTTPS over HTTP/1.1:

• 0.47 seconds average page load time
• 0.05 seconds slower than HTTP over HTTP/1.1
• 0.37 seconds slower than HTTPS over HTTP/2.0

HTTP over HTTP/1.1

• 0.42 seconds average page load time
• 0.05 seconds faster than HTTPS over HTTP/1.1
• 0.32 seconds slower than HTTPS over HTTP/2.0

HTTPS over HTTP/2.0

• 0.10 seconds average load time
• 0.32 seconds faster than HTTP over HTTP/1.1
• 0.37 seconds faster than HTTPS over HTTPS/1.1