diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 90325da..9c4bf11 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,7 +31,7 @@ jobs:
       - name: Install Pages runtime dependencies
         shell: bash
         run: |
-          npm install --prefix .pages-runtime --no-save --no-package-lock --ignore-scripts three@0.186.1
+          npm install --prefix .pages-runtime --no-save --no-package-lock --ignore-scripts three@0.186.1 zstddec@0.3.1
 
       - name: Validate example JavaScript
         shell: bash
diff --git a/.github/workflows/pages.yml b/.github/workflows/pages.yml
index 447a0b0..abbfce0 100644
--- a/.github/workflows/pages.yml
+++ b/.github/workflows/pages.yml
@@ -42,7 +42,7 @@ jobs:
       - name: Install Pages runtime dependencies
         shell: bash
         run: |
-          npm install --prefix .pages-runtime --no-save --no-package-lock --ignore-scripts three@0.186.1
+          npm install --prefix .pages-runtime --no-save --no-package-lock --ignore-scripts three@0.186.1 zstddec@0.3.1
 
       - name: Validate example JavaScript
         shell: bash
diff --git a/THIRD_PARTY_LICENSES b/THIRD_PARTY_LICENSES
index 5b2ac62..9dd31bb 100644
--- a/THIRD_PARTY_LICENSES
+++ b/THIRD_PARTY_LICENSES
@@ -66,3 +66,63 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
+
+4. zstddec 0.3.1
+-----------------
+
+Project: https://github.com/donmccurdy/zstddec-wasm
+License: MIT AND BSD-3-Clause
+
+The MIT License (MIT)
+
+Copyright (c) 2020 Don McCurdy
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+BSD License
+
+For Zstandard software
+
+Copyright (c) 2016-present, Yann Collet, Facebook, Inc. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+ * Neither the name Facebook nor the names of its contributors may be used to
+   endorse or promote products derived from this software without specific
+   prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
diff --git a/index.html b/index.html
index 8fba720..8c37795 100644
--- a/index.html
+++ b/index.html
@@ -20,7 +20,8 @@
     "imports": {
       "three": "https://cdn.jsdelivr.net/npm/three@0.186.1/build/three.module.js",
       "three/addons/": "https://cdn.jsdelivr.net/npm/three@0.186.1/examples/jsm/",
-      "augmenta-client-sdk": "./vendor/AugmentaClientSDK-JS/dist/esm/index.js"
+      "augmenta-client-sdk": "./vendor/AugmentaClientSDK-JS/dist/esm/index.js",
+      "zstddec": "https://cdn.jsdelivr.net/npm/zstddec@0.3.1/+esm"
     }
   }
   </script>
diff --git a/scripts/assemble-site.mjs b/scripts/assemble-site.mjs
index 15d83ae..22aff51 100644
--- a/scripts/assemble-site.mjs
+++ b/scripts/assemble-site.mjs
@@ -14,7 +14,9 @@ const root = process.cwd();
 const out = join(root, '_site');
 const rev = (process.env.GITHUB_SHA || 'local').slice(0, 12);
 const threeRoot = join(root, '.pages-runtime', 'node_modules', 'three');
+const zstdRoot = join(root, '.pages-runtime', 'node_modules', 'zstddec');
 const sdkOut = join(out, 'vendor', 'AugmentaClientSDK-JS', rev, 'dist', 'esm');
+const zstdOut = join(out, 'vendor', 'zstddec', rev);
 
 function requirePath(path, label) {
   if (!existsSync(path)) {
@@ -32,10 +34,31 @@ function replaceRequired(source, search, replacement) {
 requirePath(join(root, 'vendor', 'AugmentaClientSDK-JS', 'dist', 'esm'), 'built Augmenta SDK');
 requirePath(join(root, 'vendor', 'qrcode-generator', 'qrcode.js'), 'vendored QR generator');
 requirePath(join(threeRoot, 'build', 'three.module.js'), 'Three.js runtime');
+requirePath(join(zstdRoot, 'package.json'), 'Zstd decoder package');
+
+const zstdPackage = JSON.parse(readFileSync(join(zstdRoot, 'package.json'), 'utf8'));
+const zstdExports = zstdPackage.exports;
+const zstdEntrypoint = (
+  typeof zstdExports === 'string'
+    ? zstdExports
+    : zstdExports?.['.']?.browser
+      ?? zstdExports?.['.']?.default
+      ?? zstdExports?.browser
+      ?? zstdExports?.default
+      ?? zstdPackage.browser
+      ?? zstdPackage.module
+      ?? zstdPackage.main
+);
+if (typeof zstdEntrypoint !== 'string' || !zstdEntrypoint) {
+  throw new Error('Could not resolve the zstddec browser entrypoint.');
+}
+const zstdEntrypointRelative = zstdEntrypoint.replace(/^\.\//, '');
+requirePath(join(zstdRoot, zstdEntrypointRelative), 'Zstd browser decoder entrypoint');
 
 rmSync(out, { recursive: true, force: true });
 mkdirSync(join(out, 'src'), { recursive: true });
 mkdirSync(sdkOut, { recursive: true });
+mkdirSync(zstdOut, { recursive: true });
 mkdirSync(join(out, 'vendor', 'qrcode-generator'), { recursive: true });
 
 copyFileSync(join(root, 'index.html'), join(out, 'index.html'));
@@ -54,6 +77,10 @@ cpSync(
   sdkOut,
   { recursive: true }
 );
+// zstddec embeds the WebAssembly decoder in its browser package, so copying the
+// package keeps compressed Augmenta streams self-contained on GitHub Pages with
+// no runtime CDN dependency.
+cpSync(zstdRoot, zstdOut, { recursive: true });
 copyFileSync(
   join(root, 'vendor', 'qrcode-generator', 'qrcode.js'),
   join(out, 'vendor', 'qrcode-generator', 'qrcode.js')
@@ -98,6 +125,11 @@ html = replaceRequired(
   './vendor/AugmentaClientSDK-JS/dist/esm/index.js',
   `./vendor/AugmentaClientSDK-JS/${rev}/dist/esm/index.js`
 );
+html = replaceRequired(
+  html,
+  'https://cdn.jsdelivr.net/npm/zstddec@0.3.1/+esm',
+  `./vendor/zstddec/${rev}/${zstdEntrypointRelative}`
+);
 html = replaceRequired(html, './src/styles.css', `./src/styles.css?v=${rev}`);
 html = replaceRequired(html, './src/qr.js', `./src/qr.js?v=${rev}`);
 html = replaceRequired(html, './src/main.js', `./src/main.js?v=${rev}`);
diff --git a/src/connection.js b/src/connection.js
index 7aab7d2..e378ef1 100644
--- a/src/connection.js
+++ b/src/connection.js
@@ -6,6 +6,26 @@ import { APP_VERSION } from './app-info.js';
 const RECONNECT_DELAY_MS = 1000;
 const CONNECTION_ATTEMPT_TIMEOUT_MS = 2500;
 
+let zstdDecompressorPromise;
+
+async function getZstdDecompressor() {
+  if (!zstdDecompressorPromise) {
+    zstdDecompressorPromise = import('zstddec')
+      .then(async ({ ZSTDDecoder }) => {
+        const decoder = new ZSTDDecoder();
+        await decoder.init();
+        return (data) => decoder.decode(data);
+      })
+      .catch((error) => {
+        // Allow a later reconnect attempt to retry initialization if loading the
+        // local decoder failed transiently.
+        zstdDecompressorPromise = undefined;
+        throw error;
+      });
+  }
+  return zstdDecompressorPromise;
+}
+
 // Three.js is Y-up, right-handed and metre-based. Ask Augmenta/Pleiades to
 // deliver tracking and setup data directly in that convention.
 const THREE_JS_AXIS_TRANSFORM = Object.freeze({
@@ -38,6 +58,7 @@ export function createConnectionController({
   let targetIndex = 0;
   let targetKey = '';
   let attemptTimer;
+  let connectionAttemptGeneration = 0;
 
   function getState() {
     return { wantsConnection, socketOpen, retrying, activeVersion, phase, note };
@@ -70,6 +91,7 @@ export function createConnectionController({
   }
 
   function stopTransport(reason = 'User disconnect') {
+    connectionAttemptGeneration += 1;
     clearReconnectTimer();
     clearAttemptTimer();
     socketOpen = false;
@@ -107,7 +129,7 @@ export function createConnectionController({
 
     reconnectTimer = window.setTimeout(() => {
       reconnectTimer = undefined;
-      attemptConnection();
+      void attemptConnection();
     }, delay);
   }
 
@@ -119,14 +141,15 @@ export function createConnectionController({
     publish('connecting', `Server uses protocol V${version}. Reconnecting with the matching parser…`);
     reconnectTimer = window.setTimeout(() => {
       reconnectTimer = undefined;
-      attemptConnection();
+      void attemptConnection();
     }, 0);
   }
 
-  function attemptConnection() {
+  async function attemptConnection() {
     if (!wantsConnection) return;
 
     clearReconnectTimer();
+    const attemptGeneration = ++connectionAttemptGeneration;
 
     let target;
     let protocol;
@@ -160,10 +183,25 @@ export function createConnectionController({
       publish('connecting', `Connecting to ${target.label} with protocol V${version}…`);
     }
 
+    let decompressor;
+    try {
+      decompressor = await getZstdDecompressor();
+    } catch (error) {
+      if (attemptGeneration !== connectionAttemptGeneration || !wantsConnection) return;
+      wantsConnection = false;
+      retrying = false;
+      const message = error instanceof Error ? error.message : String(error);
+      publish('error', `Could not initialize Zstd decompression: ${message}`);
+      return;
+    }
+
+    if (attemptGeneration !== connectionAttemptGeneration || !wantsConnection) return;
+
     const connection = new AugmentaWebSocketClient(target.url, {
       clientName: 'Augmenta Three.js Debug Viewer',
       applicationName: 'Augmenta ThreeJS Example',
       applicationVersion: APP_VERSION,
+      decompressor,
       options: {
         version,
         downSample,
@@ -171,7 +209,11 @@ export function createConnectionController({
         streamClusters,
         streamClusterPoints,
         streamZonePoints: true,
-        useCompression: false,
+        // Keep the realtime stream compressed by default, matching the Unity,
+        // TouchDesigner and VVVV clients. This cuts WebSocket bandwidth and
+        // backlog pressure; zstddec is initialized before the connection and
+        // the JS SDK invokes it synchronously before parsing each binary frame.
+        useCompression: true,
         displayPointIntensity: true,
         // Quaternions preserve Pleiades' exact OBB orientation. The viewer
         // performs the left-handed -> right-handed basis reflection explicitly.
@@ -196,7 +238,7 @@ export function createConnectionController({
       socketOpen = true;
       publish(
         'connected',
-        `Connected to ${target.label}. Protocol V${activeVersion}; uncompressed debug stream.`
+        `Connected to ${target.label}. Protocol V${activeVersion}; Zstd-compressed debug stream.`
       );
     });
 
@@ -274,7 +316,7 @@ export function createConnectionController({
     autoNegotiatedVersion = undefined;
     wantsConnection = true;
     retrying = false;
-    attemptConnection();
+    void attemptConnection();
   }
 
   function stop() {
@@ -290,7 +332,7 @@ export function createConnectionController({
     retrying = false;
     autoNegotiatedVersion = undefined;
     stopTransport(reason);
-    attemptConnection();
+    void attemptConnection();
   }
 
   return { getState, start, stop, restart };
diff --git a/tests/websocket-compression.test.mjs b/tests/websocket-compression.test.mjs
new file mode 100644
index 0000000..aab059e
--- /dev/null
+++ b/tests/websocket-compression.test.mjs
@@ -0,0 +1,50 @@
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import test from 'node:test';
+
+const compressedFixture = Uint8Array.from([
+  40, 181, 47, 253, 36, 30, 241, 0, 0, 65, 117, 103, 109, 101, 110, 116,
+  97, 32, 90, 115, 116, 100, 32, 105, 110, 116, 101, 103, 114, 97, 116, 105,
+  111, 110, 32, 116, 101, 115, 116, 185, 49, 3, 224
+]);
+
+test('bundled zstd decoder can decode Augmenta binary payloads synchronously after init', async () => {
+  const zstdRoot = new URL('../.pages-runtime/node_modules/zstddec/', import.meta.url);
+  const packageJson = JSON.parse(readFileSync(new URL('package.json', zstdRoot), 'utf8'));
+  const packageExports = packageJson.exports;
+  const entrypoint = (
+    typeof packageExports === 'string'
+      ? packageExports
+      : packageExports?.['.']?.default
+        ?? packageExports?.default
+        ?? packageJson.module
+        ?? packageJson.main
+  );
+  assert.equal(typeof entrypoint, 'string');
+
+  const { ZSTDDecoder } = await import(new URL(entrypoint, zstdRoot).href);
+  const decoder = new ZSTDDecoder();
+  await decoder.init();
+
+  const decoded = decoder.decode(compressedFixture);
+  assert.equal(new TextDecoder().decode(decoded), 'Augmenta Zstd integration test');
+
+  // The SDK requires a synchronous decompressor once the transport is running.
+  const decompressor = (data) => decoder.decode(data);
+  assert.equal(
+    new TextDecoder().decode(decompressor(compressedFixture)),
+    'Augmenta Zstd integration test'
+  );
+});
+
+test('Three.js runtime requests compression and ships the decoder in the Pages artifact', () => {
+  const connection = readFileSync(new URL('../src/connection.js', import.meta.url), 'utf8');
+  const index = readFileSync(new URL('../index.html', import.meta.url), 'utf8');
+  const assemble = readFileSync(new URL('../scripts/assemble-site.mjs', import.meta.url), 'utf8');
+
+  assert.match(connection, /useCompression:\s*true/);
+  assert.match(connection, /decompressor,/);
+  assert.match(connection, /import\('zstddec'\)/);
+  assert.match(index, /zstddec@0\.3\.1\/\+esm/);
+  assert.match(assemble, /zstdEntrypointRelative/);
+});