Does Graph API support HTTP 2.0 ?

Question

Does Graph API support HTTP 2.0 ?

It's not easy to find out the supported version of HTTP, in the documents.

Answer 1

They say it's supported but the reality is different. The Graph API always uses HTTP/1.1 even if the client supports HTTP/2:

curl -sS -o /dev/null --http2 -v https://graph.microsoft.com/v1/me/messages 2>&1 | grep -i alpn
* ALPN: curl offers h2,http/1.1
* ALPN: server did not agree on a protocol. Uses default.

Whereas e.g. Outlook does support it:

curl -sS -o /dev/null --http2 -v https://outlook.cloud.microsoft 2>&1 | grep -i alpn
* ALPN: curl offers h2,http/1.1
* ALPN: server accepted h2

Answer 2

Yes, Microsoft Graph API supports HTTP 2.0. When you connect through a modern browser or application, HTTP 2.0 is usually used automatically, helping improve speed and efficiency.

Answer 3

It does, for few years now. So do the corresponding SDKs, including the PowerShell SDK for Graph.

Answer 4

The available documentation in the provided context describes Microsoft Graph in terms of its REST API surface (HTTP methods, versions v1.0 and beta, request size limits, etc.), but does not state which HTTP protocol versions (for example, HTTP/1.1 vs. HTTP/2.0) are supported by the Microsoft Graph service.

Because the supported HTTP protocol version for Microsoft Graph is not specified in the context, no statement can be made here about HTTP/2.0 support.

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References:

• Use the Microsoft Graph API
• Versioning, support, and breaking change policies for Microsoft Graph