diff --git a/.changeset/friendly-jobs-crash.md b/.changeset/friendly-jobs-crash.md
new file mode 100644
index 0000000000..7c092c0f94
--- /dev/null
+++ b/.changeset/friendly-jobs-crash.md
@@ -0,0 +1,6 @@
+---
+"@quri/squiggle-lang": patch
+"@quri/squiggle-components": patch
+---
+
+Added Tag.startOpen, Tag.startClosed, and Tag.getStartOpenState
diff --git a/packages/components/src/components/SquiggleViewer/utils.ts b/packages/components/src/components/SquiggleViewer/utils.ts
index ab9c1381f3..367b1434cc 100644
--- a/packages/components/src/components/SquiggleViewer/utils.ts
+++ b/packages/components/src/components/SquiggleViewer/utils.ts
@@ -160,6 +160,12 @@ export const shouldBeginCollapsed = (
   value: SqValueWithContext,
   path: SqValuePath
 ): boolean => {
+  const startOpenState = value.tags.startOpenState();
+  if (startOpenState === "open") {
+    return false;
+  } else if (startOpenState === "closed") {
+    return true;
+  }
   const childrenValues = getChildrenValues(value);
   if (path.isRoot()) {
     return childrenValues.length > 30;
diff --git a/packages/components/src/stories/SquigglePlayground.stories.tsx b/packages/components/src/stories/SquigglePlayground.stories.tsx
index 9bca523e9a..dcd6efc209 100644
--- a/packages/components/src/stories/SquigglePlayground.stories.tsx
+++ b/packages/components/src/stories/SquigglePlayground.stories.tsx
@@ -291,17 +291,26 @@ export const Tagged: Story = {
   args: {
     defaultCode: `z = 34 -> Tag.format(".1f")
 
-    @name("My favorite Dist")
-    @doc("This is a long description")
-    @format("$.2")
-    x = 5 to 10
-    
-    @showAs(Plot.numericFn)
-    @name("My favorite Fn")
-    fn = {|e| e}
+@name("My favorite Dist")
+@doc("This is a long description")
+@format("$.2")
+x = 5 to 10
 
-    bar =  [x, fn]
-    
-    y = x -> Tag.getAll`,
+@showAs(Plot.numericFn)
+@name("My favorite Fn")
+fn = {|e| e}
+
+@hide
+bar =  [x, fn]
+
+@startOpen
+s = 4 to 10
+
+@startClosed
+@showAs(Plot.numericFn)
+@name("My favorite Fn2")
+fn2 = {|e| e} 
+
+y = x -> Tag.getAll`,
   },
 };
diff --git a/packages/squiggle-lang/__tests__/library/tag_test.ts b/packages/squiggle-lang/__tests__/library/tag_test.ts
index e4640ca5ce..9f023f7212 100644
--- a/packages/squiggle-lang/__tests__/library/tag_test.ts
+++ b/packages/squiggle-lang/__tests__/library/tag_test.ts
@@ -29,6 +29,15 @@ describe("Tags", () => {
     testEvalToBe("3 -> Tag.hide -> Tag.getHide", "true");
   });
 
+  describe("startOpenToggle", () => {
+    testEvalToBe("3 -> Tag.startOpen -> Tag.getStartOpenState", '"open"');
+    testEvalToBe("3 -> Tag.startClosed -> Tag.getStartOpenState", '"closed"');
+    testEvalToBe(
+      "3 -> Tag.startClosed -> Tag.startOpen -> Tag.getStartOpenState",
+      '"open"'
+    );
+  });
+
   describe("omit", () => {
     testEvalToBe(
       "123 -> Tag.name('myName') -> Tag.doc('myDoc') -> Tag.format('.2%') -> Tag.omit(['name', 'doc']) -> Tag.getAll",
diff --git a/packages/squiggle-lang/src/fr/tag.ts b/packages/squiggle-lang/src/fr/tag.ts
index 71896f3ef3..629eddabee 100644
--- a/packages/squiggle-lang/src/fr/tag.ts
+++ b/packages/squiggle-lang/src/fr/tag.ts
@@ -289,6 +289,50 @@ example2 = {|x| x + 1}`,
       }),
     ],
   }),
+  maker.make({
+    name: "startOpen",
+    description: `When the value is first displayed, it will begin open in the viewer. Refresh the page to reset.`,
+    displaySection: "Tags",
+    definitions: [
+      makeDefinition(
+        [frWithTags(frAny({ genericName: "A" }))],
+        frWithTags(frAny({ genericName: "A" })),
+        ([{ value, tags }]) => ({
+          value,
+          tags: tags.merge({ startOpenState: "open" }),
+        }),
+        { isDecorator: true }
+      ),
+    ],
+  }),
+  maker.make({
+    name: "startClosed",
+    description: `When the value is first displayed, it will begin collapsed in the viewer. Refresh the page to reset.`,
+    displaySection: "Tags",
+    definitions: [
+      makeDefinition(
+        [frWithTags(frAny({ genericName: "A" }))],
+        frWithTags(frAny({ genericName: "A" })),
+        ([{ value, tags }]) => ({
+          value,
+          tags: tags.merge({ startOpenState: "closed" }),
+        }),
+        { isDecorator: true }
+      ),
+    ],
+  }),
+  maker.make({
+    name: "getStartOpenState",
+    displaySection: "Tags",
+    description: `Returns the startOpenState of a value, which can be "open", "closed", or "" if no startOpenState is set. Set using \`Tag.startOpen\` and \`Tag.startClosed\`.`,
+    definitions: [
+      makeDefinition(
+        [frWithTags(frAny())],
+        frString,
+        ([{ tags }]) => tags?.value.startOpenState || "",
+      ),
+    ],
+  }),
   maker.make({
     name: "notebook",
     description: `Displays the list of values as a notebook. This means that element indices are hidden, and the values are displayed in a vertical list. Useful for displaying combinations of text and values.`,
diff --git a/packages/squiggle-lang/src/public/SqValue/SqTags.ts b/packages/squiggle-lang/src/public/SqValue/SqTags.ts
index cd2798dd77..0d9a6f6937 100644
--- a/packages/squiggle-lang/src/public/SqValue/SqTags.ts
+++ b/packages/squiggle-lang/src/public/SqValue/SqTags.ts
@@ -36,4 +36,8 @@ export class SqTags {
   notebook(): boolean | undefined {
     return this.tags.notebook();
   }
+
+  startOpenState(): "open" | "closed" | undefined {
+    return this.tags.startOpenState();
+  }
 }
diff --git a/packages/squiggle-lang/src/value/valueTags.ts b/packages/squiggle-lang/src/value/valueTags.ts
index 6ab122dfae..ef1ce8fe9a 100644
--- a/packages/squiggle-lang/src/value/valueTags.ts
+++ b/packages/squiggle-lang/src/value/valueTags.ts
@@ -11,6 +11,7 @@ export type ValueTagsType = {
   dateFormat?: string;
   hidden?: boolean;
   notebook?: boolean;
+  startOpenState?: "open" | "closed";
 };
 
 type ValueTagsTypeName = keyof ValueTagsType;
@@ -23,6 +24,7 @@ const valueTagsTypeNames: ValueTagsTypeName[] = [
   "dateFormat",
   "hidden",
   "notebook",
+  "startOpenState",
 ];
 
 function convertToValueTagsTypeName(
@@ -69,6 +71,9 @@ export class ValueTags {
     if (value.notebook) {
       result.push(["notebook", vBool(value.notebook)]);
     }
+    if (value.startOpenState) {
+      result.push(["startOpenState", vString(value.startOpenState)]);
+    }
     return result;
   }
 
@@ -128,4 +133,8 @@ export class ValueTags {
   notebook() {
     return this.value.notebook;
   }
+
+  startOpenState() {
+    return this.value.startOpenState;
+  }
 }