diff --git a/.github/workflows/wasm-site.yml b/.github/workflows/wasm-site.yml
index d93a9b5..947af09 100644
--- a/.github/workflows/wasm-site.yml
+++ b/.github/workflows/wasm-site.yml
@@ -76,6 +76,7 @@ jobs:
             const browser = await chromium.launch({ headless: true });
             const page = await browser.newPage();
             await page.goto('http://127.0.0.1:8766/?v=' + Date.now());
+            await page.selectOption('#sampleSelect', { index: 4 });
             await page.click('#runButton');
             await page.waitForFunction(
               () => document.querySelector('#status')?.textContent === 'Passed',
@@ -83,9 +84,13 @@ jobs:
               { timeout: 60000 }
             );
             const output = await page.locator('#output').textContent();
+            const throughput = await page.locator('#throughputMetric').textContent();
             if (!output.includes('"ok" : true') && !output.includes('"ok":true')) {
               throw new Error(output);
             }
+            if (!throughput.includes('/s')) {
+              throw new Error(`Expected throughput metric, got: ${throughput}`);
+            }
             await browser.close();
           })();
           NODE
diff --git a/README.md b/README.md
index 05b1ae0..96adb53 100644
--- a/README.md
+++ b/README.md
@@ -49,7 +49,7 @@ try parser.parseDocuments(from: url) { document in
 }
 ```
 
-## WASM Browser Smoke Site
+## WASM Browser Benchmark Site
 
 Live site:
 
@@ -68,8 +68,10 @@ bash scripts/serve-wasm-site.sh
 ```
 
 Then open `http://localhost:8080` and click **Run WASM Test**. The page loads
-`pureyaml-streaming-wasm-smoke.wasm`, runs a chunked document-stream parse in
-the browser through a WASI shim, captures stdout, and renders pass/fail.
+`pureyaml-streaming-wasm-smoke.wasm`, lets you choose from 10+ public real-world
+YAML files, fetches the selected file in JavaScript, feeds the bytes to Swift
+through WASI stdin, and reports fetch time, parse time, throughput, document
+count, and stdout JSON.
 
 ## Relationship To PureYAML
 
diff --git a/Sources/PureYAMLStreamingWasmSmoke/main.swift b/Sources/PureYAMLStreamingWasmSmoke/main.swift
index c176e28..8502d98 100644
--- a/Sources/PureYAMLStreamingWasmSmoke/main.swift
+++ b/Sources/PureYAMLStreamingWasmSmoke/main.swift
@@ -4,13 +4,14 @@ import PureYAMLStreaming
 
 struct SmokeResult: Encodable {
     var ok: Bool
+    var inputByteCount: Int
     var documentCount: Int
     var firstName: String?
     var lastName: String?
     var message: String
 }
 
-let yaml = Data(
+let fallbackYAML = Data(
     """
     ---
     name: browser-0
@@ -31,25 +32,29 @@ let yaml = Data(
 )
 
 do {
-    let parser = PureYAMLStreaming.Parser(chunkSize: 7)
+    let input = CommandLine.arguments.count > 1
+        ? FileHandle.standardInput.readDataToEndOfFile()
+        : Data()
+    let yaml = input.isEmpty ? fallbackYAML : input
+    let parser = PureYAMLStreaming.Parser(chunkSize: 31)
     let documents = try parser.collectDocuments(data: yaml)
     let names = documents.compactMap { document in
         stringValue("name", in: document.value)
     }
-    let ok = documents.count == 3
-        && names.first == "browser-0"
-        && names.last == "browser-2"
+    let ok = !documents.isEmpty
     let result = SmokeResult(
         ok: ok,
+        inputByteCount: yaml.count,
         documentCount: documents.count,
         firstName: names.first,
         lastName: names.last,
-        message: ok ? "PureYAMLStreaming WASM smoke passed" : "PureYAMLStreaming WASM smoke failed",
+        message: ok ? "PureYAMLStreaming WASM parse passed" : "PureYAMLStreaming WASM parse found no documents",
     )
     print(try renderJSON(result))
 } catch {
     let result = SmokeResult(
         ok: false,
+        inputByteCount: 0,
         documentCount: 0,
         firstName: nil,
         lastName: nil,
diff --git a/WasmSite/index.html b/WasmSite/index.html
index fb395c1..c764d83 100644
--- a/WasmSite/index.html
+++ b/WasmSite/index.html
@@ -3,26 +3,56 @@
   <head>
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
-    <title>PureYAMLStreaming WASM Smoke</title>
+    <title>PureYAMLStreaming WASM Benchmark</title>
     <link rel="stylesheet" href="./style.css" />
   </head>
   <body>
     <main>
       <section class="card">
         <p class="eyebrow">PureYAMLStreaming</p>
-        <h1>WASM Streaming Smoke Test</h1>
+        <h1>Live WASM YAML Benchmark</h1>
         <p>
-          This page loads the Swift WASI build in the browser, runs a
-          document-streaming parse, captures stdout, and reports whether the
-          smoke test passed.
+          Pick a public real-world YAML file. The browser fetches it, feeds the
+          bytes to the Swift WASI executable through stdin, and times the
+          document-streaming parse live.
         </p>
-        <button id="runButton" type="button">Run WASM Test</button>
+        <label for="sampleSelect">Public YAML example</label>
+        <select id="sampleSelect"></select>
+        <label for="urlInput">URL</label>
+        <input id="urlInput" type="url" autocomplete="off" />
+        <button id="runButton" type="button">Run Benchmark</button>
         <div id="status" class="status idle">Idle</div>
       </section>
 
+      <section class="card">
+        <h2>Timing</h2>
+        <dl class="metrics">
+          <div>
+            <dt>Bytes</dt>
+            <dd id="bytesMetric">-</dd>
+          </div>
+          <div>
+            <dt>Fetch</dt>
+            <dd id="fetchMetric">-</dd>
+          </div>
+          <div>
+            <dt>Swift parse</dt>
+            <dd id="parseMetric">-</dd>
+          </div>
+          <div>
+            <dt>Throughput</dt>
+            <dd id="throughputMetric">-</dd>
+          </div>
+          <div>
+            <dt>Documents</dt>
+            <dd id="documentsMetric">-</dd>
+          </div>
+        </dl>
+      </section>
+
       <section class="card">
         <h2>Output</h2>
-        <pre id="output">Click "Run WASM Test".</pre>
+        <pre id="output">Pick a YAML file and click "Run Benchmark".</pre>
       </section>
     </main>
 
diff --git a/WasmSite/main.js b/WasmSite/main.js
index 6f549d7..fa4a7d0 100644
--- a/WasmSite/main.js
+++ b/WasmSite/main.js
@@ -6,29 +6,116 @@ import {
 } from "https://esm.sh/@bjorn3/browser_wasi_shim@0.3.0";
 
 const runButton = document.querySelector("#runButton");
+const sampleSelect = document.querySelector("#sampleSelect");
+const urlInput = document.querySelector("#urlInput");
 const statusElement = document.querySelector("#status");
 const outputElement = document.querySelector("#output");
+const bytesMetric = document.querySelector("#bytesMetric");
+const fetchMetric = document.querySelector("#fetchMetric");
+const parseMetric = document.querySelector("#parseMetric");
+const throughputMetric = document.querySelector("#throughputMetric");
+const documentsMetric = document.querySelector("#documentsMetric");
 const params = new URLSearchParams(location.search);
 const wasmURL = params.get("wasm") || "./pureyaml-streaming-wasm-smoke.wasm.gz";
+let modulePromise = null;
+
+const samples = [
+  {
+    name: "GitHub REST API OpenAPI (9.5 MB)",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/github-rest-api.yaml",
+  },
+  {
+    name: "Zoom OpenAPI (5.0 MB)",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/api-guru-zoom-openapi.yaml",
+  },
+  {
+    name: "Stripe OpenAPI (3.7 MB)",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/api-guru-stripe-openapi.yaml",
+  },
+  {
+    name: "cert-manager Helm values (65 KB)",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/cert-manager-values.yaml",
+  },
+  {
+    name: "cert-manager CRD (44 KB)",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/cert-manager-certificate-crd.yaml",
+  },
+  {
+    name: "Kubernetes Prow presubmits (14 KB)",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/prow-cluster-api-presubmits.yaml",
+  },
+  {
+    name: "Prometheus config (12 KB)",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/prometheus-conf-good.yml",
+  },
+  {
+    name: "USPTO OpenAPI",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/openapi-uspto.yaml",
+  },
+  {
+    name: "OpenAPI petstore expanded",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/openapi-petstore-expanded.yaml",
+  },
+  {
+    name: "Bitnami Apache values",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/bitnami-apache-values.yaml",
+  },
+  {
+    name: "GitHub Actions Swift format",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/github-actions-swift-format.yml",
+  },
+  {
+    name: "Docker Compose Prometheus/Grafana",
+    url: "https://raw.githubusercontent.com/mihaelamj/PureYAMLGeekbench/main/Fixtures/real-yaml/awesome-compose-prometheus-grafana-compose-yaml.yaml",
+  },
+];
+
+for (const sample of samples) {
+  const option = document.createElement("option");
+  option.value = sample.url;
+  option.textContent = sample.name;
+  sampleSelect.append(option);
+}
+urlInput.value = samples[0].url;
 
 runButton.addEventListener("click", () => {
-  runSmokeTest().catch((error) => {
+  runBenchmark().catch((error) => {
     renderFailure(error);
   });
 });
 
-async function runSmokeTest() {
+sampleSelect.addEventListener("change", () => {
+  urlInput.value = sampleSelect.value;
+});
+
+async function runBenchmark() {
+  const sourceURL = urlInput.value.trim();
+  if (!sourceURL) {
+    throw new Error("Choose or enter a YAML URL first.");
+  }
+
   runButton.disabled = true;
   statusElement.className = "status idle";
-  statusElement.textContent = "Running...";
-  outputElement.textContent = "Loading WASM...";
+  statusElement.textContent = "Fetching YAML...";
+  outputElement.textContent = "";
+  resetMetrics();
 
-  const wasmBytes = await loadWasmBytes(wasmURL);
+  const moduleLoadStart = performance.now();
+  const module = await loadWasmModule(wasmURL);
+  const moduleLoadMS = performance.now() - moduleLoadStart;
+
+  const fetchStart = performance.now();
+  const response = await fetch(cacheBustedURL(sourceURL), { cache: "no-store" });
+  if (!response.ok) {
+    throw new Error(`Failed to fetch YAML: HTTP ${response.status}`);
+  }
+  const yamlBytes = new Uint8Array(await response.arrayBuffer());
+  const fetchMS = performance.now() - fetchStart;
 
   let stdoutText = "";
   let stderrText = "";
   const fds = [
-    new OpenFile(new File([])),
+    new OpenFile(new File(yamlBytes)),
     ConsoleStdout.lineBuffered((line) => {
       stdoutText += `${line}\n`;
     }),
@@ -36,20 +123,33 @@ async function runSmokeTest() {
       stderrText += `${line}\n`;
     }),
   ];
-  const wasi = new WASI([], [], fds);
-  const wasm = await WebAssembly.compile(wasmBytes);
-  const instance = await WebAssembly.instantiate(wasm, {
+  const wasi = new WASI(["pureyaml-streaming-wasm-smoke", sourceURL], [], fds);
+  statusElement.textContent = "Running Swift parser...";
+  const parseStart = performance.now();
+  const instance = await WebAssembly.instantiate(module, {
     wasi_snapshot_preview1: wasi.wasiImport,
   });
-
   wasi.start(instance);
+  const parseMS = performance.now() - parseStart;
 
   const parsed = parseSmokeOutput(stdoutText);
   const ok = parsed?.ok === true;
+  const throughput = yamlBytes.byteLength / (parseMS / 1000);
 
   statusElement.className = ok ? "status pass" : "status fail";
   statusElement.textContent = ok ? "Passed" : "Failed";
+  bytesMetric.textContent = formatBytes(yamlBytes.byteLength);
+  fetchMetric.textContent = formatDuration(fetchMS);
+  parseMetric.textContent = formatDuration(parseMS);
+  throughputMetric.textContent = `${formatBytes(throughput)}/s`;
+  documentsMetric.textContent = parsed?.documentCount ?? "-";
   outputElement.textContent = [
+    `url: ${sourceURL}`,
+    `moduleLoad: ${formatDuration(moduleLoadMS)}`,
+    `fetch: ${formatDuration(fetchMS)}`,
+    `parse: ${formatDuration(parseMS)}`,
+    `throughput: ${formatBytes(throughput)}/s`,
+    "",
     "stdout:",
     stdoutText || "(empty)",
     "",
@@ -59,6 +159,13 @@ async function runSmokeTest() {
   runButton.disabled = false;
 }
 
+async function loadWasmModule(url) {
+  if (!modulePromise) {
+    modulePromise = loadWasmBytes(url).then((bytes) => WebAssembly.compile(bytes));
+  }
+  return modulePromise;
+}
+
 async function loadWasmBytes(url) {
   const response = await fetch(url);
   if (!response.ok) {
@@ -75,6 +182,12 @@ async function loadWasmBytes(url) {
   return new Response(stream).arrayBuffer();
 }
 
+function cacheBustedURL(url) {
+  const parsedURL = new URL(url, location.href);
+  parsedURL.searchParams.set("_pureyaml_bench", `${Date.now()}-${Math.random().toString(36).slice(2)}`);
+  return parsedURL.href;
+}
+
 function parseSmokeOutput(text) {
   try {
     return JSON.parse(text);
@@ -90,3 +203,27 @@ function renderFailure(error) {
   runButton.disabled = false;
 }
 
+function resetMetrics() {
+  bytesMetric.textContent = "-";
+  fetchMetric.textContent = "-";
+  parseMetric.textContent = "-";
+  throughputMetric.textContent = "-";
+  documentsMetric.textContent = "-";
+}
+
+function formatDuration(milliseconds) {
+  if (milliseconds < 1000) {
+    return `${milliseconds.toFixed(1)} ms`;
+  }
+  return `${(milliseconds / 1000).toFixed(3)} s`;
+}
+
+function formatBytes(byteCount) {
+  if (byteCount < 1024) {
+    return `${byteCount.toFixed(0)} B`;
+  }
+  if (byteCount < 1024 * 1024) {
+    return `${(byteCount / 1024).toFixed(1)} KiB`;
+  }
+  return `${(byteCount / 1024 / 1024).toFixed(2)} MiB`;
+}
diff --git a/WasmSite/style.css b/WasmSite/style.css
index dc2028d..6ff88e2 100644
--- a/WasmSite/style.css
+++ b/WasmSite/style.css
@@ -10,12 +10,12 @@
 body {
   margin: 0;
   min-height: 100vh;
-  display: grid;
-  place-items: center;
+  padding: 28px 0;
 }
 
 main {
-  width: min(920px, calc(100vw - 32px));
+  width: min(1040px, calc(100vw - 32px));
+  margin: 0 auto;
   display: grid;
   gap: 20px;
 }
@@ -52,10 +52,29 @@ p {
   opacity: 0.82;
 }
 
+label {
+  display: block;
+  margin: 18px 0 8px;
+  font-weight: 800;
+}
+
+select,
+input {
+  box-sizing: border-box;
+  width: 100%;
+  border: 1px solid color-mix(in srgb, CanvasText 18%, transparent);
+  border-radius: 14px;
+  padding: 12px 14px;
+  background: Canvas;
+  color: CanvasText;
+  font: inherit;
+}
+
 button {
   appearance: none;
   border: 0;
   border-radius: 999px;
+  margin-top: 18px;
   padding: 12px 18px;
   font: inherit;
   font-weight: 700;
@@ -86,6 +105,34 @@ button:disabled {
   background: color-mix(in srgb, #c21f39 30%, transparent);
 }
 
+.metrics {
+  margin: 0;
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
+  gap: 14px;
+}
+
+.metrics div {
+  border: 1px solid color-mix(in srgb, CanvasText 14%, transparent);
+  border-radius: 16px;
+  padding: 16px;
+  background: color-mix(in srgb, Canvas 96%, CanvasText 4%);
+}
+
+dt {
+  margin: 0 0 8px;
+  font-size: 12px;
+  font-weight: 800;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  opacity: 0.65;
+}
+
+dd {
+  margin: 0;
+  font: 700 24px/1.1 ui-monospace, SFMono-Regular, Menlo, monospace;
+}
+
 pre {
   margin: 0;
   white-space: pre-wrap;