A comparison of SPDY and HTTP performance

We compare the performance of SPDY and HTTP in a variety of setting using a controlled tested study. We rely in publically available software and run with mostly default configurations. It is not our aim to extract every last bit of performance out of either SPDY or HTTP. Rather, we are interested in understanding how various mechanisms used by the two protocols affect page load times. This report documents our preliminary findings. For the web pages we tested, we find that if one applies all the known optimizations to HTTP 1.1, then SPDY does not always have a significant performance advantage. We also find that for small web pages, the overhead of SSL handshakes can have a significant impact on SPDY’s performance.