diff --git a/site/src/contexts/useProxyLatency.ts b/site/src/contexts/useProxyLatency.ts
index 334638bc9314d..ff8be8cd66135 100644
--- a/site/src/contexts/useProxyLatency.ts
+++ b/site/src/contexts/useProxyLatency.ts
@@ -15,6 +15,11 @@ export interface ProxyLatencyReport {
 	latencyMS: number;
 	// at is when the latency was recorded.
 	at: Date;
+	/**
+	 * nextHopProtocol can determine if HTTP/2 is being used.
+	 * https://developer.mozilla.org/docs/Web/API/PerformanceResourceTiming/nextHopProtocol
+	 */
+	nextHopProtocol?: string;
 }
 
 interface ProxyLatencyAction {
@@ -151,6 +156,7 @@ export const useProxyLatency = (
 			// https://developer.mozilla.org/en-US/docs/Web/API/Performance_API/Resource_timing
 			let latencyMS = 0;
 			let accurate = false;
+			let nextHopProtocol: string | undefined = undefined;
 			if (
 				"requestStart" in entry &&
 				(entry as PerformanceResourceTiming).requestStart !== 0
@@ -159,6 +165,7 @@ export const useProxyLatency = (
 				const timingEntry = entry as PerformanceResourceTiming;
 				latencyMS = timingEntry.responseStart - timingEntry.requestStart;
 				accurate = true;
+				nextHopProtocol = timingEntry.nextHopProtocol;
 			} else {
 				// This is the total duration of the request and will be off by a good margin.
 				// This is a fallback if the better timing is not available.
@@ -175,7 +182,8 @@ export const useProxyLatency = (
 					latencyMS,
 					accurate,
 					at: new Date(),
-				},
+					nextHopProtocol: nextHopProtocol,
+				} as ProxyLatencyReport,
 			};
 			dispatchProxyLatencies(update);
 			// Also save to local storage to persist the latency across page refreshes.
diff --git a/site/src/pages/UserSettingsPage/WorkspaceProxyPage/WorkspaceProxyRow.tsx b/site/src/pages/UserSettingsPage/WorkspaceProxyPage/WorkspaceProxyRow.tsx
index 0005e1fe28a68..e0af17f51baa1 100644
--- a/site/src/pages/UserSettingsPage/WorkspaceProxyPage/WorkspaceProxyRow.tsx
+++ b/site/src/pages/UserSettingsPage/WorkspaceProxyPage/WorkspaceProxyRow.tsx
@@ -26,12 +26,30 @@ export const ProxyRow: FC<ProxyRowProps> = ({ proxy, latency }) => {
 	// All users can see healthy/unhealthy, some can see more.
 	let statusBadge = <ProxyStatus proxy={proxy} />;
 	let shouldShowMessages = false;
+	const extraWarnings: string[] = [];
+	if (latency?.nextHopProtocol) {
+		switch (latency.nextHopProtocol) {
+			case "http/0.9":
+			case "http/1.0":
+			case "http/1.1":
+				extraWarnings.push(
+					// biome-ignore lint/style/useTemplate: easier to read short lines
+					`Requests to the proxy from current browser are using "${latency.nextHopProtocol}". ` +
+						"The proxy server might not support HTTP/2. " +
+						"For usability reasons, HTTP/2 or above is recommended. " +
+						"Pages may fail to load if the web browser's concurrent " +
+						"connection limit per host is reached.",
+				);
+		}
+	}
+
 	if ("status" in proxy) {
 		const wsproxy = proxy as WorkspaceProxy;
 		statusBadge = <DetailedProxyStatus proxy={wsproxy} />;
 		shouldShowMessages = Boolean(
 			(wsproxy.status?.report?.warnings &&
 				wsproxy.status?.report?.warnings.length > 0) ||
+				extraWarnings.length > 0 ||
 				(wsproxy.status?.report?.errors &&
 					wsproxy.status?.report?.errors.length > 0),
 		);
@@ -84,7 +102,10 @@ export const ProxyRow: FC<ProxyRowProps> = ({ proxy, latency }) => {
 						colSpan={4}
 						css={{ padding: "0 !important", borderBottom: 0 }}
 					>
-						<ProxyMessagesRow proxy={proxy as WorkspaceProxy} />
+						<ProxyMessagesRow
+							proxy={proxy as WorkspaceProxy}
+							extraWarnings={extraWarnings}
+						/>
 					</TableCell>
 				</TableRow>
 			)}
@@ -94,9 +115,13 @@ export const ProxyRow: FC<ProxyRowProps> = ({ proxy, latency }) => {
 
 interface ProxyMessagesRowProps {
 	proxy: WorkspaceProxy;
+	extraWarnings: string[];
 }
 
-const ProxyMessagesRow: FC<ProxyMessagesRowProps> = ({ proxy }) => {
+const ProxyMessagesRow: FC<ProxyMessagesRowProps> = ({
+	proxy,
+	extraWarnings,
+}) => {
 	const theme = useTheme();
 
 	return (
@@ -109,7 +134,7 @@ const ProxyMessagesRow: FC<ProxyMessagesRowProps> = ({ proxy }) => {
 				title={
 					<span css={{ color: theme.palette.warning.light }}>Warnings</span>
 				}
-				messages={proxy.status?.report?.warnings}
+				messages={[...(proxy.status?.report?.warnings ?? []), ...extraWarnings]}
 			/>
 		</>
 	);
diff --git a/site/src/testHelpers/entities.ts b/site/src/testHelpers/entities.ts
index 3c329cb0dbf9c..5686e503eaf60 100644
--- a/site/src/testHelpers/entities.ts
+++ b/site/src/testHelpers/entities.ts
@@ -206,6 +206,10 @@ export const MockProxyLatencies: Record<string, ProxyLatencyReport> = {
 						100) %
 					250,
 				at: new Date(),
+				nextHopProtocol:
+					proxy.id === "8444931c-0247-4171-842a-569d9f9cbadb"
+						? "http/1.1"
+						: "h2",
 			};
 			return acc;
 		},

<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html xmlns='http://www.w3.org/1999/xhtml'>
<head>
<title>pFad - Phonifier reborn</title>
<meta http-equiv='Content-Type' content='text/html; charset=utf-8' />
</head>
<body>
<h1>Pfad - The Proxy pFad of &#169; 2024 Garber Painting. All rights reserved.</h1>


<!-- Disclaimer -->
<p>Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.</p>
<br>
<p>Alternative Proxies:</p><p><a href="http://rainy.clevelandohioweatherforecast.com/php-proxy/index.php?q=https://patch-diff.githubusercontent.com/raw/coder/coder/pull/15917.diff" target="_blank">Alternative Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/index.php?u=https://patch-diff.githubusercontent.com/raw/coder/coder/pull/15917.diff" target="_blank">pFad Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v3index.php?u=https://patch-diff.githubusercontent.com/raw/coder/coder/pull/15917.diff" target="_blank">pFad v3 Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v4index.php?u=https://patch-diff.githubusercontent.com/raw/coder/coder/pull/15917.diff" target="_blank">pFad v4 Proxy</a></p></body>
</html>