{"id":2910,"date":"2018-03-27T00:00:00","date_gmt":"2018-03-27T00:00:00","guid":{"rendered":"https:\/\/azure.microsoft.com\/blog\/announcing-http-2-support-in-azure-app-service"},"modified":"2025-07-01T08:15:03","modified_gmt":"2025-07-01T15:15:03","slug":"announcing-http-2-support-in-azure-app-service","status":"publish","type":"post","link":"https:\/\/azure.microsoft.com\/en-us\/blog\/announcing-http-2-support-in-azure-app-service\/","title":{"rendered":"Announcing HTTP\/2 support in Azure App Service"},"content":{"rendered":"\n

The Azure App Service team is happy to announce the global deployment of support for the HTTP\/2 protocol for all apps hosted on App Service. HTTP\/2 has been the top customer request<\/a> we have received, and we are excited to light up support!<\/p>\n\n\n\n

What is HTTP\/2?<\/h2>\n\n\n\n

HTTP\/2 is a rework of how HTTP semantics flow over TCP connections, and HTTP\/2 support is present in Windows 10 and Windows Server 2016. HTTP\/2 is a major upgrade after nearly two decades of HTTP\/1.1 use and reduces the impact of latency and connection load on web servers.<\/p>\n\n\n\n

The major advance of HTTP\/1.1 was the use of persistent connections to service multiple requests in a row. In HTTP\/2, a persistent connection can be used to service multiple simultaneous requests. In the process, HTTP\/2 introduces several additional features that improve the efficiency of HTTP over the network.<\/p>\n\n\n\n

One connection for multiple requests<\/h2>\n\n\n\n

Every TCP connection requires a round trip to set up. If you\u2019re using encryption, the TLS handshake takes another 1-2 round trips. All this happens before the first byte of the first response can be sent. By reusing an existing connection instead of setting up a new one, this overhead can be shared by many requests. HTTP\/2 sharply reduces the need for a request to wait while a new connection is established, or wait for an existing connection to become idle. Because a single connection is multiplexed between many requests, the request can usually be sent immediately without waiting for other requests to finish.<\/p>\n\n\n\n

Header compression with HPACK<\/h2>\n\n\n\n

HTTP has supported compression of data for ages. Headers, however, are sent as uncompressed text, with a lot of redundancy between requests. (Many of the longest headers are sent with exactly the same value on every request!) HTTP\/2 introduces HPACK, a compression scheme for HTTP headers which reduces the redundancy between requests.<\/p>\n\n\n\n

Compression also helps multiplexing, because requests are smaller. This enables clients to make many requests in their first packets on a connection, while TCP flow control windows are still small.<\/p>\n\n\n\n

What are the key differences from HTTP\/1.x?<\/h2>\n\n\n\n