Merge pull request #313575 from dlepow/http22

[APIM] HTTP/2 support in classic tiers

Author: prmerger-automator[bot]

articles/api-management/api-management-gateways-overview.md

@@ -8,7 +8,7 @@ ms.service: azure-api-management
 ms.custom:
   - build-2024
 ms.topic: concept-article
-ms.date: 02/17/2026
+ms.date: 03/23/2026
 ms.author: danlep
 ---
 
@@ -85,15 +85,16 @@ The following tables compare features available in the following API Management
 | [Managed domain certificates](configure-custom-domain.md?tabs=managed#domain-certificate-options) |  ✔️ | ❌ | ✔️ | ❌ | ❌ |
 | [TLS settings](api-management-howto-manage-protocols-ciphers.md) |  ✔️ | ✔️ | ✔️ | ✔️ | ❌ |
 | **HTTP/2** (Client-to-gateway) | ✔️<sup>4</sup> | ✔️<sup>4</sup> |❌ | ✔️ | ❌ |
-| **HTTP/2** (Gateway-to-backend) |  ❌ | ❌ | ❌ | ✔️<sup>5</sup> | ❌ |
+| **HTTP/2** (Gateway-to-backend) |  ✔️<sup>7</sup> | ❌ | ❌ | ✔️<sup>5</sup> | ❌ |
 | API threat detection with [Defender for APIs](protect-with-defender-for-apis.md) | ✔️ | ✔️ |  ❌ | ❌ | ❌ |
 
 <sup>1</sup> Depends on how the gateway is deployed, but is the responsibility of the customer.<br/>
 <sup>2</sup> Connectivity to the self-hosted gateway v2 [configuration endpoint](self-hosted-gateway-overview.md#fqdn-dependencies) requires DNS resolution of the endpoint hostname.<br/>
 <sup>3</sup> CA root certificates for self-hosted gateway are managed separately per gateway.<br/>
 <sup>4</sup> Client protocol needs to be enabled.<br/>
 <sup>5</sup> Configure using the [forward-request](forward-request-policy.md) policy.<br/>
-<sup>6</sup> Configure CA certificate details for backend certificate authentication in [backend](backends.md) settings.
+<sup>6</sup> Configure CA certificate details for backend certificate authentication in [backend](backends.md) settings.<br/>
+<sup>7</sup> In preview for classic tier instances created starting January 2026. Contact support to enable for existing classic tier instances.
 
 ### Backend APIs
 
@@ -110,7 +111,7 @@ The following tables compare features available in the following API Management
 | [Pass-through GraphQL](graphql-apis-overview.md) |  ✔️ | ✔️ |✔️ | ✔️ | ✔️ |
 | [Synthetic GraphQL](graphql-apis-overview.md)|  ✔️ |  ✔️ | ✔️<sup>1</sup> | ✔️<sup>1</sup> | ❌ |
 | [Pass-through WebSocket](websocket-api.md) |  ✔️ |  ✔️ | ❌ | ✔️ | ✔️ |
-| [Pass-through gRPC](grpc-api.md)  |  ✔️ | ❌ | ❌ | ✔️ | ❌ |
+| [Pass-through gRPC](grpc-api.md)  |  ✔️<sup>1</sup> | ❌ | ❌ | ✔️ | ❌ |
 | [OData](import-api-from-odata.md)  |  ✔️ |  ✔️ | ✔️ | ✔️ | ✔️ |
 | [Azure OpenAI in Microsoft Foundry models and LLMs](azure-ai-foundry-api.md) | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
 | [Pass-through MCP server](expose-existing-mcp-server.md) | ✔️  | ✔️ | ❌ | ✔️ | ❌ |
@@ -119,6 +120,9 @@ The following tables compare features available in the following API Management
 | [Circuit breaker in backend](backends.md#circuit-breaker)  |  ✔️ | ✔️ | ❌ | ✔️ | ✔️ |
 | [Load-balanced backend pool](backends.md#load-balanced-pool)  |  ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
 
+<sup>1</sup> In preview for classic tier instances created starting January 2026. Contact support to enable for existing classic tier instances.
+
+
 ### Policies
 
 Managed and self-hosted gateways support all available [policies](api-management-policies.md) in policy definitions with the following exceptions. See the policy reference for details about each policy.