From e067928d73f7b9f21338034eb4011bcf495e6f30 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Popek?=
 <78650133+Varixo@users.noreply.github.com>
Date: Fri, 17 Jul 2026 17:23:13 +0200
Subject: [PATCH] fix computed signal serialization default

---
 .changeset/calm-computed-secrets.md           |  5 +++
 .../core/reactive-primitives/signal-api.ts    |  2 +-
 .../src/core/shared/serdes/serdes.unit.ts     | 38 ++++++++++++-------
 packages/qwik/src/core/shared/types.ts        |  4 +-
 4 files changed, 32 insertions(+), 17 deletions(-)
 create mode 100644 .changeset/calm-computed-secrets.md

diff --git a/.changeset/calm-computed-secrets.md b/.changeset/calm-computed-secrets.md
new file mode 100644
index 00000000000..56b9271eb82
--- /dev/null
+++ b/.changeset/calm-computed-secrets.md
@@ -0,0 +1,5 @@
+---
+'@qwik.dev/core': patch
+---
+
+fix: avoid serializing computed values by default.
diff --git a/packages/qwik/src/core/reactive-primitives/signal-api.ts b/packages/qwik/src/core/reactive-primitives/signal-api.ts
index f1ecc8a45d7..249c74f266b 100644
--- a/packages/qwik/src/core/reactive-primitives/signal-api.ts
+++ b/packages/qwik/src/core/reactive-primitives/signal-api.ts
@@ -29,7 +29,7 @@ export const createComputedSignal = <T>(
   return new ComputedSignalImpl<T>(
     options?.container || null,
     qrl as ComputeQRL<T>,
-    getComputedSignalFlags(options?.serializationStrategy || 'always'),
+    getComputedSignalFlags(options?.serializationStrategy || 'never'),
     options
   );
 };
diff --git a/packages/qwik/src/core/shared/serdes/serdes.unit.ts b/packages/qwik/src/core/shared/serdes/serdes.unit.ts
index e9bac17e54f..7482e589574 100644
--- a/packages/qwik/src/core/shared/serdes/serdes.unit.ts
+++ b/packages/qwik/src/core/shared/serdes/serdes.unit.ts
@@ -607,35 +607,40 @@ describe('shared-serialization', () => {
       const clean = createComputed$(() => foo.value + 2, { serializationStrategy: 'always' });
       const never = createComputed$(() => foo.value + 3, { serializationStrategy: 'never' });
       const always = createComputed$(() => foo.value + 4, { serializationStrategy: 'always' });
+      const defaultStrategy = createComputed$(() => foo.value + 5);
       const noSer = createComputed$(() => noSerialize({ foo }));
       // note that this won't subscribe because we're not setting up the context
       // do not read `dirty` to keep it dirty
       expect(clean.value).toBe(2);
       expect(never.value).toBe(3);
       expect(always.value).toBe(4);
-      const objs = await serialize(dirty, clean, never, always, noSer);
+      expect(defaultStrategy.value).toBe(5);
+      const objs = await serialize(dirty, clean, never, always, defaultStrategy, noSer);
       expect(_dumpState(objs)).toMatchInlineSnapshot(`
         "
         0 ComputedSignal [
-          QRL "6#1#-2"
+          QRL "7#1#-2"
         ]
         1 ComputedSignal [
-          QRL "6#2#-3"
+          QRL "7#2#-3"
           Constant undefined
           {number} 2
         ]
         2 ComputedSignal [
-          QRL "6#3#-4"
+          QRL "7#3#-4"
         ]
         3 ComputedSignal [
-          QRL "6#4#-5"
+          QRL "7#4#-5"
           Constant undefined
           {number} 4
         ]
         4 ComputedSignal [
-          QRL "6#5#-6"
+          QRL "7#5#-6"
         ]
-        5 Signal [
+        5 ComputedSignal [
+          QRL "7#6#-7"
+        ]
+        6 Signal [
           {number} 0
           EffectSubscriptionNoData [
             RootRef 1
@@ -649,14 +654,19 @@ describe('shared-serialization', () => {
             RootRef 3
             Constant '.'
           ]
+          EffectSubscriptionNoData [
+            RootRef 4
+            Constant '.'
+          ]
         ]
-        6 {string} "mock-chunk"
-        7 {string} "describe_describe_it_dirty_createComputed_ahnh0V4rf6g"
-        8 {string} "describe_describe_it_clean_createComputed_0ZTfN4iJ0tg"
-        9 {string} "describe_describe_it_never_createComputed_1HbLed7JXyo"
-        10 {string} "describe_describe_it_always_createComputed_4nMmgHlUOog"
-        11 {string} "describe_describe_it_noSer_createComputed_pXwl00hYYQQ"
-        (454 chars)"
+        7 {string} "mock-chunk"
+        8 {string} "describe_describe_it_dirty_createComputed_ahnh0V4rf6g"
+        9 {string} "describe_describe_it_clean_createComputed_0ZTfN4iJ0tg"
+        10 {string} "describe_describe_it_never_createComputed_1HbLed7JXyo"
+        11 {string} "describe_describe_it_always_createComputed_4nMmgHlUOog"
+        12 {string} "describe_describe_it_defaultStrategy_createComputed_i9O7shypysA"
+        13 {string} "describe_describe_it_noSer_createComputed_pXwl00hYYQQ"
+        (552 chars)"
       `);
     });
     it(title(TypeIds.SerializerSignal), async () => {
diff --git a/packages/qwik/src/core/shared/types.ts b/packages/qwik/src/core/shared/types.ts
index ab2ec6baffe..5b1962fa1d5 100644
--- a/packages/qwik/src/core/shared/types.ts
+++ b/packages/qwik/src/core/shared/types.ts
@@ -142,8 +142,8 @@ export interface QContainerElement extends Element {
  * value during SSR.
  *
  * - `never`: The value is never serialized. When the component is resumed, the value will be
- *   recalculated when it is first read.
- * - `always`: The value is always serialized. This is the default.
+ *   recalculated when it is first read. This is the default for computed signals.
+ * - `always`: The value is always serialized. This is the default for async signals.
  *
  * **IMPORTANT**: When you use `never`, your serialized HTML is smaller, but the recalculation will
  * trigger subscriptions, meaning that other signals using this signal will recalculate, even if