diff --git a/packages/codemirror/autocomplete.mjs b/packages/codemirror/autocomplete.mjs
index 05473b5e..c065c365 100644
--- a/packages/codemirror/autocomplete.mjs
+++ b/packages/codemirror/autocomplete.mjs
@@ -10,9 +10,9 @@ const getInnerText = (html) => {
   return div.textContent || div.innerText || '';
 };
 
-function Autocomplete({ doc }) {
+export function Autocomplete({ doc, label }) {
   return h`<div class="prose dark:prose-invert max-h-[400px] overflow-auto">
-<h1 class="pt-0 mt-0">${getDocLabel(doc)}</h1>
+<h1 class="pt-0 mt-0">${label || getDocLabel(doc)}</h1>
 ${doc.description}
 <ul>
   ${doc.params?.map(
@@ -50,12 +50,7 @@ const jsdocCompletions = jsdoc.docs
   .map((doc) /*: Completion */ => ({
     label: getDocLabel(doc),
     // detail: 'xxx', // An optional short piece of information to show (with a different style) after the label.
-    info: () => {
-      const node = document.createElement('div');
-      const ac = Autocomplete({ doc });
-      node.appendChild(ac);
-      return node;
-    },
+    info: () => Autocomplete({ doc }),
     type: 'function', // https://codemirror.net/docs/ref/#autocomplete.Completion.type
   }));
 
diff --git a/packages/codemirror/codemirror.mjs b/packages/codemirror/codemirror.mjs
index 234e8e1a..6713ac6f 100644
--- a/packages/codemirror/codemirror.mjs
+++ b/packages/codemirror/codemirror.mjs
@@ -7,6 +7,7 @@ import { Compartment, EditorState, Prec } from '@codemirror/state';
 import { EditorView, highlightActiveLineGutter, highlightActiveLine, keymap, lineNumbers } from '@codemirror/view';
 import { Pattern, Drawer, repl, cleanupDraw } from '@strudel.cycles/core';
 import { isAutoCompletionEnabled } from './autocomplete.mjs';
+import { isTooltipEnabled } from './tooltip.mjs';
 import { flash, isFlashEnabled } from './flash.mjs';
 import { highlightMiniLocations, isPatternHighlightingEnabled, updateMiniLocations } from './highlight.mjs';
 import { keybindings } from './keybindings.mjs';
@@ -19,6 +20,7 @@ const extensions = {
   isLineNumbersDisplayed: (on) => (on ? lineNumbers() : []),
   theme,
   isAutoCompletionEnabled,
+  isTooltipEnabled,
   isPatternHighlightingEnabled,
   isActiveLineHighlighted: (on) => (on ? [highlightActiveLine(), highlightActiveLineGutter()] : []),
   isFlashEnabled,
diff --git a/packages/codemirror/tooltip.mjs b/packages/codemirror/tooltip.mjs
new file mode 100644
index 00000000..7b7a36db
--- /dev/null
+++ b/packages/codemirror/tooltip.mjs
@@ -0,0 +1,76 @@
+import { hoverTooltip } from '@codemirror/view';
+import jsdoc from '../../doc.json';
+import { Autocomplete } from './autocomplete.mjs';
+
+const getDocLabel = (doc) => doc.name || doc.longname;
+
+let ctrlDown = false;
+
+// Record Control key event to trigger or block the tooltip depending on the state
+window.addEventListener(
+  'keyup',
+  function (e) {
+    if (e.key == 'Control') {
+      ctrlDown = false;
+    }
+  },
+  true,
+);
+
+window.addEventListener(
+  'keydown',
+  function (e) {
+    if (e.key == 'Control') {
+      ctrlDown = true;
+    }
+  },
+  true,
+);
+
+export const strudelTooltip = hoverTooltip(
+  (view, pos, side) => {
+    // Word selection from CodeMirror Hover Tooltip example https://codemirror.net/examples/tooltip/#hover-tooltips
+    if (!ctrlDown) {
+      return null;
+    }
+    let { from, to, text } = view.state.doc.lineAt(pos);
+    let start = pos,
+      end = pos;
+    while (start > from && /\w/.test(text[start - from - 1])) {
+      start--;
+    }
+    while (end < to && /\w/.test(text[end - from])) {
+      end++;
+    }
+    if ((start == pos && side < 0) || (end == pos && side > 0)) {
+      return null;
+    }
+    let word = text.slice(start - from, end - from);
+    // Get entry from Strudel documentation
+    let entry = jsdoc.docs.filter((doc) => getDocLabel(doc) === word)[0];
+    if (!entry) {
+      // Try for synonyms
+      entry = jsdoc.docs.filter((doc) => doc.synonyms && doc.synonyms.includes(word))[0];
+      if (!entry) {
+        return null;
+      }
+    }
+
+    return {
+      pos: start,
+      end,
+      above: false,
+      arrow: true,
+      create(view) {
+        let dom = document.createElement('div');
+        dom.className = 'strudel-tooltip';
+        const ac = Autocomplete({ doc: entry, label: word });
+        dom.appendChild(ac);
+        return { dom };
+      },
+    };
+  },
+  { hoverTime: 10 },
+);
+
+export const isTooltipEnabled = (on) => (on ? strudelTooltip : []);