Real-World Performance Measurements

Empirical studies consistently show negligible performance differences between well-configured HTTP and HTTPS sites, with HTTPS often performing better due to HTTP/2 benefits. Google reported that SSL/TLS accounts for less than 1% of CPU load and less than 2% of network overhead in their deployments. Major CDN providers report similar findings, with HTTPS overhead lost in the noise of other performance factors.

Page load time comparisons must account for protocol versions and optimization levels. Comparing optimized HTTPS/2 sites against HTTP/1.1 sites shows significant performance advantages for HTTPS. Even comparing HTTPS/1.1 against HTTP/1.1 shows minimal differences with modern hardware and optimizations. The key factors affecting performance are protocol version and optimization quality rather than encryption presence.

Mobile performance particularly benefits from HTTPS optimizations. Mobile networks often have higher latency and packet loss than wired connections. HTTP/2's single connection approach performs better under these conditions than HTTP/1.1's multiple connections. Connection reuse through session resumption becomes more valuable on mobile networks. The performance benefits often outweigh any encryption overhead on mobile devices.

Geographic distribution affects HTTPS performance differently than HTTP. CDN providers terminating SSL at edge locations minimize handshake latency by bringing certificate validation closer to users. This distributed approach can make HTTPS faster than HTTP for global audiences. Anycast SSL deployments further improve performance by routing users to optimal endpoints for their location.