HTTP/1.1 has been the workhorse of the internet for over a decade, but its limitations have become more and more apparent as web traffic has exploded in recent years. To address these limitations, the HTTP/2 protocol was introduced in 2015. In this article, we’ll explore the key ways in which HTTP/2 is faster than HTTP/1.1.
1. Multiplexing
One of the biggest limitations of HTTP/1.1 is that it only allows a single request-response cycle at a time over a single TCP connection. This means that if a webpage has many resources, such as images, scripts, and stylesheets, each of these resources must be requested and delivered one at a time, in a serial fashion.
HTTP/2, on the other hand, supports multiplexing, which means that multiple requests and responses can be sent over a single TCP connection at the same time. This allows resources to be requested and delivered in parallel, significantly reducing page load times.
2. Server Push
HTTP/1.1 requires the client to request each resource individually. This means that the server has no way of knowing which resources the client will need in the future, and must wait for each request before sending the corresponding resource.
HTTP/2 introduces a new feature called Server Push, which allows the server to send resources to the client before they are requested. This can significantly reduce the latency of subsequent requests, since the required resources are already in the client’s cache.
3. Header Compression
HTTP/1.1 headers are sent with each request and response, and can contain a lot of redundant information. This can result in a lot of unnecessary data being sent over the network, slowing down page load times.
HTTP/2 uses a new compression algorithm called HPACK to compress headers before they are sent over the network. This reduces the amount of data that needs to be transmitted, improving performance and reducing bandwidth usage.
4. Binary Protocol
HTTP/1.1 uses a text-based protocol, which is easy to read and understand, but can be inefficient for computers to parse. This is because text-based protocols require more processing to convert the text into machine-readable code.
HTTP/2, on the other hand, uses a binary protocol, which is designed to be more efficient for computers to parse. This reduces the processing time required for each request, resulting in faster page load times.
5. Prioritization
In HTTP/1.1, all requests have the same priority, which can lead to slower page load times if some resources are more important than others.
HTTP/2 allows requests to be prioritized based on their importance, allowing critical resources to be delivered more quickly. This can significantly improve page load times, especially on complex webpages.
In conclusion, HTTP/2 is faster than HTTP/1.1 due to its support for multiplexing, server push, header compression, binary protocol, and prioritization. While HTTP/1.1 served the internet well for many years, its limitations have become more and more apparent as web traffic has increased. By addressing these limitations, HTTP/2 is poised to become the new standard for web communication.