diff --git a/Cargo.toml b/Cargo.toml
index 88156a8acc..4f8802f35f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -289,7 +289,7 @@ zip = { version = "2.4.1", default-features = false, features = ["flate2"] }
 
 opentelemetry = "0.27.0"
 opentelemetry-http = "0.27.0"
-opentelemetry-otlp = { version = "0.27.0", features = ["logs", "http-proto", "http-json", "populate-logs-event-name"] }
+opentelemetry-otlp = { version = "0.27.0", features = ["logs", "http-proto", "http-json", "populate-logs-event-name", "grpc-tonic"] }
 opentelemetry-semantic-conventions = { version = "0.27.0", features = ["semconv_experimental"] }
 opentelemetry_sdk = { version = "0.27.0", features = ["rt-tokio", "trace"] }
 
diff --git a/ext/telemetry/lib.rs b/ext/telemetry/lib.rs
index cd03f1d776..07784a5630 100644
--- a/ext/telemetry/lib.rs
+++ b/ext/telemetry/lib.rs
@@ -870,10 +870,10 @@ pub fn init(
 
   // Parse the `OTEL_EXPORTER_OTLP_PROTOCOL` variable. The opentelemetry_*
   // crates don't do this automatically.
-  // TODO(piscisaureus): enable GRPC support.
   let protocol = match env::var("OTEL_EXPORTER_OTLP_PROTOCOL").as_deref() {
     Ok("http/protobuf") => Protocol::HttpBinary,
     Ok("http/json") => Protocol::HttpJson,
+    Ok("grpc") => Protocol::Grpc,
     Ok("") | Err(env::VarError::NotPresent) => Protocol::HttpBinary,
     Ok(protocol) => {
       return Err(deno_core::anyhow::anyhow!(
@@ -930,45 +930,78 @@ pub fn init(
   // `OTEL_EXPORTER_OTLP_ENDPOINT` environment variable. Additional headers can
   // be specified using `OTEL_EXPORTER_OTLP_HEADERS`.
 
-  let client = hyper_client::HyperClient::new()?;
+  let (span_exporter, metric_exporter, log_exporter) = match protocol {
+    Protocol::Grpc => {
+      let span_exporter = opentelemetry_otlp::SpanExporter::builder()
+        .with_tonic()
+        .build()?;
+      let temporality_preference =
+        env::var("OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE")
+          .ok()
+          .map(|s| s.to_lowercase());
+      let temporality = match temporality_preference.as_deref() {
+        None | Some("cumulative") => Temporality::Cumulative,
+        Some("delta") => Temporality::Delta,
+        Some("lowmemory") => Temporality::LowMemory,
+        Some(other) => {
+          return Err(deno_core::anyhow::anyhow!(
+            "Invalid value for OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE: {}",
+            other
+          ));
+        }
+      };
+      let metric_exporter = opentelemetry_otlp::MetricExporter::builder()
+        .with_tonic()
+        .with_temporality(temporality)
+        .build()?;
+      let log_exporter = opentelemetry_otlp::LogExporter::builder()
+        .with_tonic()
+        .build()?;
+      (span_exporter, metric_exporter, log_exporter)
+    }
+    _ => {
+      let client = hyper_client::HyperClient::new()?;
+      let span_exporter = HttpExporterBuilder::default()
+        .with_http_client(client.clone())
+        .with_protocol(protocol)
+        .build_span_exporter()?;
+      let temporality_preference =
+        env::var("OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE")
+          .ok()
+          .map(|s| s.to_lowercase());
+      let temporality = match temporality_preference.as_deref() {
+        None | Some("cumulative") => Temporality::Cumulative,
+        Some("delta") => Temporality::Delta,
+        Some("lowmemory") => Temporality::LowMemory,
+        Some(other) => {
+          return Err(deno_core::anyhow::anyhow!(
+            "Invalid value for OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE: {}",
+            other
+          ));
+        }
+      };
+      let metric_exporter = HttpExporterBuilder::default()
+        .with_http_client(client.clone())
+        .with_protocol(protocol)
+        .build_metrics_exporter(temporality)?;
+      let log_exporter = HttpExporterBuilder::default()
+        .with_http_client(client)
+        .with_protocol(protocol)
+        .build_log_exporter()?;
+      (span_exporter, metric_exporter, log_exporter)
+    }
+  };
 
-  let span_exporter = HttpExporterBuilder::default()
-    .with_http_client(client.clone())
-    .with_protocol(protocol)
-    .build_span_exporter()?;
   let mut span_processor =
     BatchSpanProcessor::builder(span_exporter, OtelSharedRuntime).build();
   span_processor.set_resource(&resource);
 
-  let temporality_preference =
-    env::var("OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE")
-      .ok()
-      .map(|s| s.to_lowercase());
-  let temporality = match temporality_preference.as_deref() {
-    None | Some("cumulative") => Temporality::Cumulative,
-    Some("delta") => Temporality::Delta,
-    Some("lowmemory") => Temporality::LowMemory,
-    Some(other) => {
-      return Err(deno_core::anyhow::anyhow!(
-        "Invalid value for OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE: {}",
-        other
-      ));
-    }
-  };
-  let metric_exporter = HttpExporterBuilder::default()
-    .with_http_client(client.clone())
-    .with_protocol(protocol)
-    .build_metrics_exporter(temporality)?;
   let metric_reader = DenoPeriodicReader::new(metric_exporter);
   let meter_provider = SdkMeterProvider::builder()
     .with_reader(metric_reader)
     .with_resource(resource.clone())
     .build();
 
-  let log_exporter = HttpExporterBuilder::default()
-    .with_http_client(client)
-    .with_protocol(protocol)
-    .build_log_exporter()?;
   let log_processor =
     BatchLogProcessor::builder(log_exporter, OtelSharedRuntime).build();
   log_processor.set_resource(&resource);
diff --git a/tests/specs/cli/otel_basic/.gitignore b/tests/specs/cli/otel_basic/.gitignore
new file mode 100644
index 0000000000..02c915e200
--- /dev/null
+++ b/tests/specs/cli/otel_basic/.gitignore
@@ -0,0 +1 @@
+opentelemetry-proto/
diff --git a/tests/specs/cli/otel_basic/__test__.jsonc b/tests/specs/cli/otel_basic/__test__.jsonc
index 31fe5e0a2b..c3158d021a 100644
--- a/tests/specs/cli/otel_basic/__test__.jsonc
+++ b/tests/specs/cli/otel_basic/__test__.jsonc
@@ -2,6 +2,17 @@
   "tests": {
     "basic": {
       "args": "run -A main.ts basic.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
+      "output": "basic.out"
+    },
+    "basic_grpc": {
+      "args": "run -A main.ts basic.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc"
+      },
       "output": "basic.out"
     },
     "basic_vsock": {
@@ -26,6 +37,16 @@
     },
     "metric": {
       "envs": {
+        "OTEL_METRIC_EXPORT_INTERVAL": "1000",
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
+      "args": "run -A main.ts metric.ts",
+      "output": "metric.out"
+    },
+    "metric_grpc": {
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc",
         "OTEL_METRIC_EXPORT_INTERVAL": "1000"
       },
       "args": "run -A main.ts metric.ts",
@@ -33,44 +54,104 @@
     },
     "fetch": {
       "args": "run -A main.ts fetch.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
       "output": "fetch.out"
     },
     "http_metric": {
       "envs": {
-        "OTEL_METRIC_EXPORT_INTERVAL": "1000"
+        "OTEL_METRIC_EXPORT_INTERVAL": "1000",
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
       },
       "args": "run -A main.ts http_metric.ts",
       "output": "http_metric.out"
     },
     "http_propagators": {
       "args": "run -A main.ts http_propagators.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
       "output": "http_propagators.out"
     },
     "node_http_metric": {
       "envs": {
-        "OTEL_METRIC_EXPORT_INTERVAL": "1000"
+        "OTEL_METRIC_EXPORT_INTERVAL": "1000",
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
       },
       "args": "run -A main.ts node_http_metric.ts",
       "output": "node_http_metric.out"
     },
     "links": {
       "args": "run -A main.ts links.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
+      "output": "links.out"
+    },
+    "links_grpc": {
+      "args": "run -A main.ts links.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc"
+      },
       "output": "links.out"
     },
     "start_active_span": {
       "args": "run -A main.ts start_active_span.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
+      "output": "start_active_span.out"
+    },
+    "start_active_span_grpc": {
+      "args": "run -A main.ts start_active_span.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc"
+      },
       "output": "start_active_span.out"
     },
     "node_http_request": {
       "args": "run -A main.ts node_http_request.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
       "output": "node_http_request.out"
     },
     "events": {
       "args": "run -A main.ts events.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
+      "output": "events.out"
+    },
+    "events_grpc": {
+      "args": "run -A main.ts events.ts",
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc"
+      },
       "output": "events.out"
     },
     "metric_temporality_delta": {
       "envs": {
+        "OTEL_METRIC_EXPORT_INTERVAL": "1000",
+        "OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE": "delta",
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
+      "args": "run -A main.ts metric_temporality.ts",
+      "output": "metric_temporality_delta.out"
+    },
+    "metric_temporality_delta_grpc": {
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc",
         "OTEL_METRIC_EXPORT_INTERVAL": "1000",
         "OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE": "delta"
       },
@@ -79,6 +160,17 @@
     },
     "metric_temporality_cumulative": {
       "envs": {
+        "OTEL_METRIC_EXPORT_INTERVAL": "1000",
+        "OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE": "cumulative",
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "http/json",
+        "OTEL_EXPORTER_OTLP_CERTIFICATE": "../../../testdata/tls/RootCA.crt"
+      },
+      "args": "run -A main.ts metric_temporality.ts",
+      "output": "metric_temporality_cumulative.out"
+    },
+    "metric_temporality_cumulative_grpc": {
+      "envs": {
+        "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc",
         "OTEL_METRIC_EXPORT_INTERVAL": "1000",
         "OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE": "cumulative"
       },
diff --git a/tests/specs/cli/otel_basic/env_file b/tests/specs/cli/otel_basic/env_file
index 5c1572df54..4447743dee 100644
--- a/tests/specs/cli/otel_basic/env_file
+++ b/tests/specs/cli/otel_basic/env_file
@@ -1,4 +1,2 @@
 OTEL_DENO=true
 DENO_UNSTABLE_OTEL_DETERMINISTIC=0
-OTEL_EXPORTER_OTLP_PROTOCOL=http/json
-OTEL_EXPORTER_OTLP_CERTIFICATE=../../../testdata/tls/RootCA.crt
diff --git a/tests/specs/cli/otel_basic/main.ts b/tests/specs/cli/otel_basic/main.ts
index 984ac685e3..184a19147e 100644
--- a/tests/specs/cli/otel_basic/main.ts
+++ b/tests/specs/cli/otel_basic/main.ts
@@ -1,11 +1,130 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 
+import grpc from "npm:@grpc/grpc-js";
+import protoLoader from "npm:@grpc/proto-loader";
+
 const data = {
   spans: [],
   logs: [],
   metrics: [],
 };
 
+// Download and load OTLP proto definitions (traces, metrics, logs) from GitHub if not present
+// Try to match with what's cloned into opentelemetry-proto crate
+const opentelemetryProtoTag = "1.3.2";
+async function ensureProtoFiles() {
+  if (await fileExists("./opentelemetry-proto")) return;
+  console.log("Downloading OpenTelemetry proto repo...");
+  const repo = "open-telemetry/opentelemetry-proto";
+  const url =
+    `https://github.com/${repo}/archive/refs/tags/v${opentelemetryProtoTag}.zip`;
+  const zipPath = "opentelemetry-proto.zip";
+  const unzipDir = "opentelemetry-proto";
+  // Download zip
+  const resp = await fetch(url);
+  if (!resp.ok) throw new Error(`Failed to download proto zip: ${resp.status}`);
+  const zipData = new Uint8Array(await resp.arrayBuffer());
+  await Deno.writeFile(zipPath, zipData);
+  // Unzip
+  const p = Deno.run({ cmd: ["unzip", "-q", zipPath, "-d", unzipDir] });
+  const status = await p.status();
+  if (!status.success) throw new Error("Failed to unzip proto files");
+  // Clean up
+  await Deno.remove(zipPath);
+}
+
+async function fileExists(path) {
+  try {
+    await Deno.stat(path);
+    return true;
+  } catch (_) {
+    return false;
+  }
+}
+
+function handleOtlpRequest(call, callback, type) {
+  // call.request is the OTLP protobuf message
+  // For test purposes, just push to data and return success
+  console.log(
+    `[grpc] Received ${type} export request`,
+    JSON.stringify(call.request),
+  );
+  if (type === "traces") {
+    call.request.resourceSpans?.forEach((rSpans) => {
+      rSpans.scopeSpans.forEach((sSpans) => {
+        data.spans.push(...sSpans.spans);
+      });
+    });
+  } else if (type === "metrics") {
+    call.request.resourceMetrics?.forEach((rMetrics) => {
+      rMetrics.scopeMetrics.forEach((sMetrics) => {
+        data.metrics.push(...sMetrics.metrics);
+      });
+    });
+  } else if (type === "logs") {
+    call.request.resourceLogs?.forEach((rLogs) => {
+      rLogs.scopeLogs.forEach((sLogs) => {
+        data.logs.push(...sLogs.logRecords);
+      });
+    });
+  }
+  callback(null, { partialSuccess: {} });
+}
+
+async function startGrpcServer(port, onReady) {
+  // Ensure proto files are present before loading
+  let otlp = await ensureProtoFiles().then(() => {
+    const packageDefinition = protoLoader.loadSync([
+      `opentelemetry/proto/collector/trace/v1/trace_service.proto`,
+      `opentelemetry/proto/collector/metrics/v1/metrics_service.proto`,
+      `opentelemetry/proto/collector/logs/v1/logs_service.proto`,
+    ], {
+      includeDirs: [
+        `./opentelemetry-proto/opentelemetry-proto-${opentelemetryProtoTag}`,
+      ],
+      keepCase: true,
+      longs: String,
+      enums: String,
+      defaults: true,
+      oneofs: true,
+    });
+    return grpc.loadPackageDefinition(packageDefinition).opentelemetry.proto;
+  });
+  const server = new grpc.Server();
+  // Register minimal OTLP services
+  server.addService(otlp.collector.trace.v1.TraceService.service, {
+    Export: (call, callback) => handleOtlpRequest(call, callback, "traces"),
+  });
+  server.addService(otlp.collector.metrics.v1.MetricsService.service, {
+    Export: (call, callback) => handleOtlpRequest(call, callback, "metrics"),
+  });
+  server.addService(otlp.collector.logs.v1.LogsService.service, {
+    Export: (call, callback) => handleOtlpRequest(call, callback, "logs"),
+  });
+  /// Read TLS key and cert files (same as HTTP server)
+  // const key = Deno.readTextFileSync("../../../testdata/tls/localhost.key");
+  // const cert = Deno.readTextFileSync("../../../testdata/tls/localhost.crt");
+  // const keyBuf = Buffer.from(key);
+  // const certBuf = Buffer.from(cert);
+  // const creds = grpc.ServerCredentials.createSsl(
+  //   null,
+  //   [{ private_key: keyBuf, cert_chain: certBuf }],
+  //   true,
+  // );
+  /// Error: Not implemented: http2.createSecureServer
+  /// Use insecure credentials for gRPC in Deno (TLS not supported)
+  const creds = grpc.ServerCredentials.createInsecure();
+  server.bindAsync(
+    `0.0.0.0:${port}`,
+    creds,
+    (err, actualPort) => {
+      if (err) throw err;
+      console.log(`[grpc] Server listening on port ${actualPort}`);
+      onReady(actualPort, server);
+    },
+  );
+}
+
 async function handler(req) {
   const body = await req.json();
   body.resourceLogs?.forEach((rLogs) => {
@@ -26,100 +145,189 @@ async function handler(req) {
   return Response.json({ partialSuccess: {} }, { status: 200 });
 }
 
-let server;
+const protocol = Deno.env.get("OTEL_EXPORTER_OTLP_PROTOCOL")?.toLowerCase();
 
-function onListen({ port }) {
-  const command = new Deno.Command(Deno.execPath(), {
-    args: [
-      "run",
-      "--env-file=env_file",
-      "-A",
-      "-q",
-      Deno.args[0],
-    ],
-    env: {
-      // rest of env is in env_file
-      OTEL_EXPORTER_OTLP_ENDPOINT: `https://localhost:${port}`,
-    },
-    stdout: "null",
-  });
-  const child = command.spawn();
-  child.status
-    .then((status) => {
-      if (status.signal) {
-        throw new Error("child process failed: " + JSON.stringify(status));
-      }
-      return server.shutdown();
-    })
-    .then(() => {
-      data.logs.sort((a, b) =>
-        Number(
-          BigInt(a.observedTimeUnixNano) - BigInt(b.observedTimeUnixNano),
-        )
-      );
-      data.spans.sort((a, b) =>
-        Number(BigInt(`0x${a.spanId}`) - BigInt(`0x${b.spanId}`))
-      );
-      // v8js metrics are non-deterministic
-      data.metrics = data.metrics.filter((m) => !m.name.startsWith("v8js"));
-      data.metrics.sort((a, b) => a.name.localeCompare(b.name));
-      for (const metric of data.metrics) {
-        if ("histogram" in metric) {
-          metric.histogram.dataPoints.sort((a, b) => {
-            const aKey = a.attributes
-              .sort((x, y) => x.key.localeCompare(y.key))
-              .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
-              .join("|");
-            const bKey = b.attributes
-              .sort((x, y) => x.key.localeCompare(y.key))
-              .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
-              .join("|");
-            return aKey.localeCompare(bKey);
-          });
-
-          for (const dataPoint of metric.histogram.dataPoints) {
-            dataPoint.attributes.sort((a, b) => {
-              return a.key.localeCompare(b.key);
-            });
+// Only run the necessary collector server
+switch (protocol) {
+  case "grpc": {
+    startGrpcServer(0, async (port, server) => {
+      const command = new Deno.Command(Deno.execPath(), {
+        args: [
+          "run",
+          "--env-file=env_file",
+          "-A",
+          "-q",
+          Deno.args[0],
+        ],
+        env: {
+          // rest of env is in env_file
+          OTEL_EXPORTER_OTLP_ENDPOINT: `http://localhost:${port}`,
+        },
+        stdout: "null",
+      });
+      const child = command.spawn();
+      child.status
+        .then((status) => {
+          if (status.signal) {
+            throw new Error("child process failed: " + JSON.stringify(status));
           }
-        }
-        if ("sum" in metric) {
-          metric.sum.dataPoints.sort((a, b) => {
-            const aKey = a.attributes
-              .sort((x, y) => x.key.localeCompare(y.key))
-              .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
-              .join("|");
-            const bKey = b.attributes
-              .sort((x, y) => x.key.localeCompare(y.key))
-              .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
-              .join("|");
-            return aKey.localeCompare(bKey);
-          });
+          server.tryShutdown(() => {});
+        })
+        .then(() => {
+          data.logs.sort((a, b) =>
+            Number(
+              BigInt(a.observedTimeUnixNano) - BigInt(b.observedTimeUnixNano),
+            )
+          );
+          data.spans.sort((a, b) =>
+            Number(BigInt(`0x${a.spanId}`) - BigInt(`0x${b.spanId}`))
+          );
+          // v8js metrics are non-deterministic
+          data.metrics = data.metrics.filter((m) => !m.name.startsWith("v8js"));
+          data.metrics.sort((a, b) => a.name.localeCompare(b.name));
+          for (const metric of data.metrics) {
+            if ("histogram" in metric) {
+              metric.histogram.dataPoints.sort((a, b) => {
+                const aKey = a.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                const bKey = b.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                return aKey.localeCompare(bKey);
+              });
 
-          for (const dataPoint of metric.sum.dataPoints) {
-            dataPoint.attributes.sort((a, b) => {
-              return a.key.localeCompare(b.key);
-            });
+              for (const dataPoint of metric.histogram.dataPoints) {
+                dataPoint.attributes.sort((a, b) => {
+                  return a.key.localeCompare(b.key);
+                });
+              }
+            }
+            if ("sum" in metric) {
+              metric.sum.dataPoints.sort((a, b) => {
+                const aKey = a.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                const bKey = b.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                return aKey.localeCompare(bKey);
+              });
+
+              for (const dataPoint of metric.sum.dataPoints) {
+                dataPoint.attributes.sort((a, b) => {
+                  return a.key.localeCompare(b.key);
+                });
+              }
+            }
           }
-        }
-      }
-      console.log(JSON.stringify(data, null, 2));
+          console.log(JSON.stringify(data, null, 2));
+        });
     });
-}
+    break;
+  }
+  case "http/protobuf":
+  case "http/json": {
+    let server;
+    function onListen({ port }) {
+      const command = new Deno.Command(Deno.execPath(), {
+        args: [
+          "run",
+          "--env-file=env_file",
+          "-A",
+          "-q",
+          Deno.args[0],
+        ],
+        env: {
+          OTEL_EXPORTER_OTLP_ENDPOINT: `https://localhost:${port}`,
+        },
+        stdout: "null",
+      });
+      const child = command.spawn();
+      child.status
+        .then((status) => {
+          if (status.signal) {
+            throw new Error("child process failed: " + JSON.stringify(status));
+          }
+          server.shutdown();
+        })
+        .then(() => {
+          data.logs.sort((a, b) =>
+            Number(
+              BigInt(a.observedTimeUnixNano) - BigInt(b.observedTimeUnixNano),
+            )
+          );
+          data.spans.sort((a, b) =>
+            Number(BigInt(`0x${a.spanId}`) - BigInt(`0x${b.spanId}`))
+          );
+          // v8js metrics are non-deterministic
+          data.metrics = data.metrics.filter((m) => !m.name.startsWith("v8js"));
+          data.metrics.sort((a, b) => a.name.localeCompare(b.name));
+          for (const metric of data.metrics) {
+            if ("histogram" in metric) {
+              metric.histogram.dataPoints.sort((a, b) => {
+                const aKey = a.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                const bKey = b.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                return aKey.localeCompare(bKey);
+              });
 
-if (Deno.env.get("OTEL_DENO_VSOCK")) {
-  server = Deno.serve({
-    cid: -1,
-    port: 4317,
-    onListen,
-    handler,
-  });
-} else {
-  server = Deno.serve({
-    key: Deno.readTextFileSync("../../../testdata/tls/localhost.key"),
-    cert: Deno.readTextFileSync("../../../testdata/tls/localhost.crt"),
-    port: 0,
-    onListen,
-    handler,
-  });
+              for (const dataPoint of metric.histogram.dataPoints) {
+                dataPoint.attributes.sort((a, b) => {
+                  return a.key.localeCompare(b.key);
+                });
+              }
+            }
+            if ("sum" in metric) {
+              metric.sum.dataPoints.sort((a, b) => {
+                const aKey = a.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                const bKey = b.attributes
+                  .sort((x, y) => x.key.localeCompare(y.key))
+                  .map(({ key, value }) => `${key}:${JSON.stringify(value)}`)
+                  .join("|");
+                return aKey.localeCompare(bKey);
+              });
+
+              for (const dataPoint of metric.sum.dataPoints) {
+                dataPoint.attributes.sort((a, b) => {
+                  return a.key.localeCompare(b.key);
+                });
+              }
+            }
+          }
+          console.log(JSON.stringify(data, null, 2));
+        });
+    }
+    if (Deno.env.get("OTEL_DENO_VSOCK")) {
+      server = Deno.serve({
+        cid: -1,
+        port: 4317,
+        onListen,
+        handler,
+      });
+    } else {
+      server = Deno.serve({
+        key: Deno.readTextFileSync("../../../testdata/tls/localhost.key"),
+        cert: Deno.readTextFileSync("../../../testdata/tls/localhost.crt"),
+        port: 0,
+        onListen,
+        handler,
+      });
+    }
+    break;
+  }
+  default:
+    throw new Error(`Unknown OTEL_EXPORTER_OTLP_PROTOCOL: ${protocol}`);
 }