diff --git a/docs/_javascript/preset_test.js b/docs/_javascript/preset_test.js
index bf5361d13..47db346ae 100644
--- a/docs/_javascript/preset_test.js
+++ b/docs/_javascript/preset_test.js
@@ -131,6 +131,13 @@
     }
   }
 
+  function hasPresetParameters(search) {
+    const params = new URLSearchParams(search || "");
+    return Object.keys(DEFAULTS).some(function (key) {
+      return params.has(key);
+    });
+  }
+
   function supportedTimeZones(selectedTimeZone) {
     const zones = new Set(["UTC"]);
     if (typeof Intl.supportedValuesOf === "function") {
@@ -723,52 +730,63 @@
   }
 
   function init(root) {
+    const search = global.location ? global.location.search : "";
+    let showTest = hasPresetParameters(search);
     let config;
     try {
       config = configFromSearch(
-        global.location ? global.location.search : "",
+        search,
         browserTimeZone()
       );
     } catch (error) {
       const box = root.querySelector('[data-role="config-error"]');
       box.hidden = false;
       box.textContent = "Invalid test URL: " + error.message;
-      root.querySelector('[data-role="content"]').hidden = true;
-      return;
+      config = configFromSearch("", browserTimeZone());
+      showTest = false;
     }
 
-    setPageText('[data-role="preset-test-page-title"]', presetPageTitle(config));
-    setPageText('[data-role="preset-test-page-summary"]', presetPageSummary(config));
-    setText(root, '[data-role="preset-test-eyebrow"]', presetEyebrow(config));
-    setText(root, '[data-field="freq-display"]', config.freq.toFixed(3));
-    setText(root, '[data-field="bw-display"]', config.bwText);
-    setText(root, '[data-field="sf"]', String(config.sf));
-    setText(root, '[data-field="cr"]', String(config.cr));
-    setText(root, '[data-role="start-zoned"]', formatZoned(config.startMs, config.tz));
-    setText(root, '[data-role="end-zoned"]', formatZoned(config.endMs, config.tz));
-    setText(root, '[data-role="display-zone"]', config.tz);
-    setText(
-      root,
-      '[data-role="epoch-range"]',
-      config.startEpoch + " → " + config.endEpoch
-    );
-    setText(
-      root,
-      '[data-role="window-summary"]',
-      "A " + formatCountdown(config.endMs - config.startMs) +
-        " window. Saved primary settings return automatically at the end."
-    );
+    const testContent = root.querySelector('[data-role="test-content"]');
+    if (testContent) testContent.hidden = !showTest;
+    const testFooter = root.querySelector('[data-role="test-content-footer"]');
+    if (testFooter) testFooter.hidden = !showTest;
+    const builderDisclosure = root.querySelector('[data-role="url-builder-disclosure"]');
+    if (builderDisclosure) builderDisclosure.open = !showTest;
 
-    const staticCommands = commandsFor(config, config.startMs);
-    setCommand(root, "primary-scheduled", staticCommands.primaryScheduled);
-    setCommand(root, "companion-scheduled", staticCommands.companionScheduled);
-    setCommand(root, "stock-cancel-during", staticCommands.stockCancelDuring);
-    setCommand(root, "stock-leave-30", staticCommands.stockLeaveIn30);
-    setCommand(root, "primary-cancel", staticCommands.primaryCancel);
-    setCommand(root, "companion-cancel-before", staticCommands.companionCancelBefore);
-    setCommand(root, "companion-cancel-during", staticCommands.companionCancelDuring);
-    setCommand(root, "companion-leave-30", staticCommands.companionLeaveIn30);
-    setCommand(root, "reset-clock", CLOCK_RESET_COMMAND);
+    if (showTest) {
+      setPageText('[data-role="preset-test-page-title"]', presetPageTitle(config));
+      setPageText('[data-role="preset-test-page-summary"]', presetPageSummary(config));
+      setText(root, '[data-role="preset-test-eyebrow"]', presetEyebrow(config));
+      setText(root, '[data-field="freq-display"]', config.freq.toFixed(3));
+      setText(root, '[data-field="bw-display"]', config.bwText);
+      setText(root, '[data-field="sf"]', String(config.sf));
+      setText(root, '[data-field="cr"]', String(config.cr));
+      setText(root, '[data-role="start-zoned"]', formatZoned(config.startMs, config.tz));
+      setText(root, '[data-role="end-zoned"]', formatZoned(config.endMs, config.tz));
+      setText(root, '[data-role="display-zone"]', config.tz);
+      setText(
+        root,
+        '[data-role="epoch-range"]',
+        config.startEpoch + " → " + config.endEpoch
+      );
+      setText(
+        root,
+        '[data-role="window-summary"]',
+        "A " + formatCountdown(config.endMs - config.startMs) +
+          " window. Saved primary settings return automatically at the end."
+      );
+
+      const staticCommands = commandsFor(config, config.startMs);
+      setCommand(root, "primary-scheduled", staticCommands.primaryScheduled);
+      setCommand(root, "companion-scheduled", staticCommands.companionScheduled);
+      setCommand(root, "stock-cancel-during", staticCommands.stockCancelDuring);
+      setCommand(root, "stock-leave-30", staticCommands.stockLeaveIn30);
+      setCommand(root, "primary-cancel", staticCommands.primaryCancel);
+      setCommand(root, "companion-cancel-before", staticCommands.companionCancelBefore);
+      setCommand(root, "companion-cancel-during", staticCommands.companionCancelDuring);
+      setCommand(root, "companion-leave-30", staticCommands.companionLeaveIn30);
+      setCommand(root, "reset-clock", CLOCK_RESET_COMMAND);
+    }
 
     const generator = root.querySelector('[data-role="url-generator"]');
     if (generator) {
@@ -846,6 +864,8 @@
       });
     });
 
+    if (!showTest) return;
+
     function render() {
       const nowMs = Date.now();
       const phase = phaseAt(config, nowMs);
@@ -956,6 +976,7 @@
     presetEyebrow: presetEyebrow,
     validateTimeZone: validateTimeZone,
     browserTimeZone: browserTimeZone,
+    hasPresetParameters: hasPresetParameters,
     supportedTimeZones: supportedTimeZones,
     phaseAt: phaseAt,
     remainingMinutes: remainingMinutes,
diff --git a/docs/preset_test.md b/docs/preset_test.md
index 871054964..c0f72105f 100644
--- a/docs/preset_test.md
+++ b/docs/preset_test.md
@@ -1,19 +1,15 @@
-# <span data-role="preset-test-page-title">Default temporary radio test · 910.1 MHz · September 21–23, 2026</span>
+# <span data-role="preset-test-page-title">Temporary radio test builder</span>
 
-Use this page to join the shared temporary radio test without overwriting the
-node's saved primary radio settings. <span data-role="preset-test-page-summary">The
-default window is <strong>Monday, September 21, 2026 at 5:00 PM through
-Wednesday, September 23 at 5:00 PM Pacific time</strong> (48 hours), using
-<strong>910.1 MHz, 500 kHz, SF8, CR7</strong>.</span>
+<span data-role="preset-test-page-summary">Choose a window and radio tuple to
+create a shareable temporary-radio test URL.</span>
 
-The page reads the complete test definition from its URL. Change the query
-parameters to reuse it for a different window, display time zone, or radio
-tuple; no source edit is required.
+Open a generated URL to see that test's status, instructions, and commands.
 
 <div class="preset-test" data-preset-test>
   <div class="preset-test-error" data-role="config-error" role="alert" hidden></div>
 
   <div data-role="content">
+    <div data-role="test-content" hidden>
     <section class="preset-test-hero" aria-labelledby="preset-test-title">
       <p class="preset-test-eyebrow" data-role="preset-test-eyebrow">MeshCore · default 48-hour temporary preset test</p>
       <div class="preset-test-hero-row">
@@ -288,10 +284,12 @@ clock</code></pre>
       </div>
     </section>
 
+    </div>
+
     <section aria-labelledby="share-title">
-      <details class="preset-test-generator-disclosure">
+      <details class="preset-test-generator-disclosure" data-role="url-builder-disclosure" open>
         <summary>
-          <h2 id="share-title">Build a link for another test</h2>
+          <h2 id="share-title">Build a temporary radio test URL</h2>
         </summary>
         <div class="preset-test-generator-disclosure-body">
           <p>
@@ -412,13 +410,17 @@ clock</code></pre>
         </div>
       </details>
     </section>
+
+    <div data-role="test-content-footer" hidden>
+      <p>
+        Primary <code>tempradioat</code> scheduling is implemented by the Simple
+        Repeater role; room-server and sensor roles use their immediate
+        <code>tempradio</code> command during the setup window. The Companion
+        scheduling commands require current full-parser firmware, and
+        <code>tempradio2</code> and <code>tempradioat2</code> require a build with
+        dual-radio-profile support. If a node reports an unknown command, use only
+        a method that its installed firmware documents.
+      </p>
+    </div>
   </div>
 </div>
-
-Primary <code>tempradioat</code> scheduling is implemented by the Simple Repeater
-role; room-server and sensor roles use their immediate <code>tempradio</code>
-command during the setup window. The Companion scheduling commands require
-current full-parser firmware, and
-<code>tempradio2</code> and <code>tempradioat2</code> require a build with
-dual-radio-profile support. If a node reports an unknown command, use only a
-method that its installed firmware documents.
diff --git a/mkdocs.yml b/mkdocs.yml
index 856447573..edb9fdf65 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -30,4 +30,4 @@ extra_javascript:
   - _javascript/telemetry_decoder.js
   - _javascript/management_decoder.js
   - _javascript/filter_tool.js
-  - _javascript/preset_test.js?v=20260921-1
+  - _javascript/preset_test.js?v=20260921-2
diff --git a/test/test_preset_test.js b/test/test_preset_test.js
index e6d7bef4b..af644c977 100644
--- a/test/test_preset_test.js
+++ b/test/test_preset_test.js
@@ -11,11 +11,9 @@ assert.match(pageSource, /data-role="preset-test-eyebrow"/);
 assert.match(pageSource, /data-role="timezone-map"/);
 assert.match(pageSource, /type="hidden" name="tz"/);
 assert.doesNotMatch(pageSource, /<select name="tz"/);
-assert.match(pageSource, /<details class="preset-test-generator-disclosure">/);
-assert.doesNotMatch(
-  pageSource,
-  /<details class="preset-test-generator-disclosure"\s+open/
-);
+assert.match(pageSource, /data-role="test-content" hidden/);
+assert.match(pageSource, /data-role="test-content-footer" hidden/);
+assert.match(pageSource, /data-role="url-builder-disclosure" open/);
 assert.match(pageSource, /data-command="primary-scheduled"/);
 assert.match(pageSource, /data-command="primary-cancel"/);
 assert.match(pageSource, /Simple Repeater primary radio/);
@@ -30,6 +28,13 @@ const query =
 const config = tool.configFromSearch(query);
 const defaults = tool.configFromSearch("", "America/Los_Angeles");
 
+assert.strictEqual(tool.hasPresetParameters(""), false);
+assert.strictEqual(tool.hasPresetParameters("?"), false);
+assert.strictEqual(tool.hasPresetParameters("?utm_source=example"), false);
+assert.strictEqual(tool.hasPresetParameters("?freq=911.3"), true);
+assert.strictEqual(tool.hasPresetParameters("?tz=UTC"), true);
+assert.strictEqual(tool.hasPresetParameters("?start=bad"), true);
+
 assert.strictEqual(config.startEpoch, 1790035200);
 assert.strictEqual(config.endEpoch, 1790208000);
 assert.strictEqual(config.endEpoch - config.startEpoch, 48 * 60 * 60);