From 6b5a07c8e344cc7a1c7ac7a0c8bbdb9648139eb4 Mon Sep 17 00:00:00 2001
From: avivkeller <me@aviv.sh>
Date: Sun, 16 Aug 2026 06:49:29 -0700
Subject: [PATCH 1/3] lib: enable web worker api by default

Signed-off-by: avivkeller <me@aviv.sh>
---
 doc/api/cli.md                                | 24 ++++++++++++-------
 doc/node.1                                    | 10 ++++----
 src/node_options.cc                           |  2 +-
 src/node_options.h                            |  2 +-
 test/common/wpt.js                            |  6 +----
 test/parallel/test-common-wpt-backends.js     |  2 +-
 .../test-common-wpt-webworker-error.js        |  2 +-
 test/parallel/test-worker-spec-differences.js |  1 -
 8 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/doc/api/cli.md b/doc/api/cli.md
index 514af04c02cd..c506a84b2d46 100644
--- a/doc/api/cli.md
+++ b/doc/api/cli.md
@@ -1563,14 +1563,6 @@ changes:
 
 Enable experimental WebAssembly System Interface (WASI) support.
 
-### `--experimental-web-worker`
-
-<!-- YAML
-added: REPLACEME
--->
-
-Enable experimental support for the Web Worker API.
-
 ### `--experimental-worker-inspection`
 
 <!-- YAML
@@ -2169,6 +2161,20 @@ changes:
 
 Disable [`Web Storage`][] support.
 
+### `--no-experimental-web-worker`
+
+<!-- YAML
+added: REPLACEME
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/65323
+    description: This feature is now enabled by default.
+-->
+
+> Stability: 1.1 - Active Development
+
+Disable support for the Web Worker API.
+
 ### `--no-extra-info-on-fatal-exception`
 
 <!-- YAML
@@ -3898,7 +3904,6 @@ one is included in the list below.
 * `--experimental-vfs`
 * `--experimental-vm-modules`
 * `--experimental-wasi-unstable-preview1`
-* `--experimental-web-worker`
 * `--force-context-aware`
 * `--force-fips`
 * `--force-node-api-uncaught-exceptions-policy`
@@ -3931,6 +3936,7 @@ one is included in the list below.
 * `--no-experimental-strip-types`
 * `--no-experimental-websocket`
 * `--no-experimental-webstorage`
+* `--no-experimental-web-worker`
 * `--no-extra-info-on-fatal-exception`
 * `--no-force-async-hooks-checks`
 * `--no-global-search-paths`
diff --git a/doc/node.1 b/doc/node.1
index dd541051de28..c33f20529cdd 100644
--- a/doc/node.1
+++ b/doc/node.1
@@ -836,9 +836,6 @@ Enable experimental ES Module support in the \fBnode:vm\fR module.
 .It Fl -experimental-wasi-unstable-preview1
 Enable experimental WebAssembly System Interface (WASI) support.
 .
-.It Fl -experimental-web-worker
-Enable experimental support for the Web Worker API.
-.
 .It Fl -experimental-worker-inspection
 Enable experimental support for the worker inspection with Chrome DevTools.
 .
@@ -1116,6 +1113,9 @@ Disable exposition of \fB<WebSocket>\fR on the global scope.
 .It Fl -no-experimental-webstorage
 Disable \fBWeb Storage\fR support.
 .
+.It Fl -no-experimental-web-worker
+Disable support for the Web Worker API.
+.
 .It Fl -no-extra-info-on-fatal-exception
 Hide extra information on fatal exception that causes exit.
 .
@@ -2027,8 +2027,6 @@ one is included in the list below.
 .It
 \fB--experimental-wasi-unstable-preview1\fR
 .It
-\fB--experimental-web-worker\fR
-.It
 \fB--force-context-aware\fR
 .It
 \fB--force-fips\fR
@@ -2093,6 +2091,8 @@ one is included in the list below.
 .It
 \fB--no-experimental-webstorage\fR
 .It
+\fB--no-experimental-web-worker\fR
+.It
 \fB--no-extra-info-on-fatal-exception\fR
 .It
 \fB--no-force-async-hooks-checks\fR
diff --git a/src/node_options.cc b/src/node_options.cc
index c743a20c31bf..e3afcabe9474 100644
--- a/src/node_options.cc
+++ b/src/node_options.cc
@@ -599,7 +599,7 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
             "experimental Web Worker API",
             BOOL_FIELD(experimental_web_worker),
             kAllowedInEnvvar,
-            false);
+            true);
   AddOption("--experimental-websocket",
             "experimental WebSocket API",
             BOOL_FIELD(experimental_websocket),
diff --git a/src/node_options.h b/src/node_options.h
index 142963dc44a2..49381f2f29cc 100644
--- a/src/node_options.h
+++ b/src/node_options.h
@@ -202,7 +202,7 @@ class EnvironmentOptions : public Options {
   DEFINE_BOOL_FIELD(experimental_addon_modules) = true;
   DEFINE_BOOL_FIELD(experimental_eventsource) = EXPERIMENTALS_DEFAULT_VALUE;
   DEFINE_BOOL_FIELD(experimental_ffi) = EXPERIMENTALS_DEFAULT_VALUE;
-  DEFINE_BOOL_FIELD(experimental_web_worker) = EXPERIMENTALS_DEFAULT_VALUE;
+  DEFINE_BOOL_FIELD(experimental_web_worker) = true;
   DEFINE_BOOL_FIELD(experimental_websocket) = true;
   DEFINE_BOOL_FIELD(experimental_sqlite) = HAVE_SQLITE;
   DEFINE_BOOL_FIELD(experimental_stream_iter) = EXPERIMENTALS_DEFAULT_VALUE;
diff --git a/test/common/wpt.js b/test/common/wpt.js
index 82b0777de5d5..b69ceb431bcf 100644
--- a/test/common/wpt.js
+++ b/test/common/wpt.js
@@ -836,11 +836,7 @@ class WPTRunner {
     this.resource = new ResourceLoader(path);
     this.concurrency = concurrency;
 
-    // Since we need to prepare the Web Worker APIs
-    // in the harness that runs on all WPT workers,
-    // we enable the API globally. This has no practical
-    // effect on the non-web-worker tests, however.
-    this.flags = ['--experimental-web-worker'];
+    this.flags = [];
     this.globalThisInitScripts = [];
     this.initScript = null;
 
diff --git a/test/parallel/test-common-wpt-backends.js b/test/parallel/test-common-wpt-backends.js
index f201adde64e1..1f88dd1277e6 100644
--- a/test/parallel/test-common-wpt-backends.js
+++ b/test/parallel/test-common-wpt-backends.js
@@ -16,7 +16,7 @@ const queueProbe = process.env.NODE_TEST_WPT_QUEUE_PROBE === '1';
 
 const harnessPath = fixtures.path('wpt', 'resources', 'testharness.js');
 const specPath = fixtures.path('wpt-backends-spec.js');
-const execArgv = ['--experimental-web-worker'];
+const execArgv = [];
 
 function payload(throws) {
   return {
diff --git a/test/parallel/test-common-wpt-webworker-error.js b/test/parallel/test-common-wpt-webworker-error.js
index 76738303cdf2..685832a640b6 100644
--- a/test/parallel/test-common-wpt-webworker-error.js
+++ b/test/parallel/test-common-wpt-webworker-error.js
@@ -10,7 +10,7 @@ const { Worker } = require('worker_threads');
 
 const workerPath = path.join(__dirname, '../common/wpt/worker.js');
 const harnessPath = fixtures.path('wpt', 'resources', 'testharness.js');
-const execArgv = ['--experimental-web-worker'];
+const execArgv = [];
 const workerData = {
   testRelativePath: 'workers/error-after-result.any.js',
   wptRunner: path.join(__dirname, '../common/wpt.js'),
diff --git a/test/parallel/test-worker-spec-differences.js b/test/parallel/test-worker-spec-differences.js
index 871745b99e04..7f67db5c43a0 100644
--- a/test/parallel/test-worker-spec-differences.js
+++ b/test/parallel/test-worker-spec-differences.js
@@ -1,4 +1,3 @@
-// Flags: --experimental-web-worker
 'use strict';
 
 const common = require('../common');

From ce023a7683197eb0a4f98100f7e7e9e65b709b14 Mon Sep 17 00:00:00 2001
From: avivkeller <me@aviv.sh>
Date: Fri, 21 Aug 2026 08:59:09 -0700
Subject: [PATCH 2/3] fixup!

---
 doc/api/cli.md     | 28 ++++++++++++++--------------
 doc/api/globals.md |  4 ++++
 doc/node.1         |  6 +++---
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/doc/api/cli.md b/doc/api/cli.md
index c506a84b2d46..950b61d5bbe2 100644
--- a/doc/api/cli.md
+++ b/doc/api/cli.md
@@ -2139,6 +2139,20 @@ changes:
 
 Disable the experimental [`node:sqlite`][] module.
 
+### `--no-experimental-web-worker`
+
+<!-- YAML
+added: REPLACEME
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/65323
+    description: This feature is now enabled by default.
+-->
+
+> Stability: 1.1 - Active Development
+
+Disable support for the Web Worker API.
+
 ### `--no-experimental-websocket`
 
 <!-- YAML
@@ -2161,20 +2175,6 @@ changes:
 
 Disable [`Web Storage`][] support.
 
-### `--no-experimental-web-worker`
-
-<!-- YAML
-added: REPLACEME
-changes:
-  - version: REPLACEME
-    pr-url: https://github.com/nodejs/node/pull/65323
-    description: This feature is now enabled by default.
--->
-
-> Stability: 1.1 - Active Development
-
-Disable support for the Web Worker API.
-
 ### `--no-extra-info-on-fatal-exception`
 
 <!-- YAML
diff --git a/doc/api/globals.md b/doc/api/globals.md
index cd6afed9626f..1642ba8b68b0 100644
--- a/doc/api/globals.md
+++ b/doc/api/globals.md
@@ -1314,6 +1314,10 @@ with the [`--no-experimental-websocket`][] CLI flag.
 
 <!-- YAML
 added: REPLACEME
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/65323
+    description: This feature is now enabled by default.
 -->
 
 > Stability: 1 - Experimental. Enable this API with the
diff --git a/doc/node.1 b/doc/node.1
index c33f20529cdd..0364a938fb10 100644
--- a/doc/node.1
+++ b/doc/node.1
@@ -1107,15 +1107,15 @@ Legacy alias for \fB--no-require-module\fR.
 .It Fl -no-experimental-sqlite
 Disable the experimental \fBnode:sqlite\fR module.
 .
+.It Fl -no-experimental-web-worker
+Disable support for the Web Worker API.
+.
 .It Fl -no-experimental-websocket
 Disable exposition of \fB<WebSocket>\fR on the global scope.
 .
 .It Fl -no-experimental-webstorage
 Disable \fBWeb Storage\fR support.
 .
-.It Fl -no-experimental-web-worker
-Disable support for the Web Worker API.
-.
 .It Fl -no-extra-info-on-fatal-exception
 Hide extra information on fatal exception that causes exit.
 .

From 67ca30a05b391926bcdfc3af17160cebe6c1b402 Mon Sep 17 00:00:00 2001
From: avivkeller <me@aviv.sh>
Date: Sat, 22 Aug 2026 16:24:06 -0700
Subject: [PATCH 3/3] fixup!

---
 doc/api/cli.md | 2 +-
 doc/node.1     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/api/cli.md b/doc/api/cli.md
index 950b61d5bbe2..7bfeaa5dc277 100644
--- a/doc/api/cli.md
+++ b/doc/api/cli.md
@@ -3934,9 +3934,9 @@ one is included in the list below.
 * `--no-experimental-global-navigator`
 * `--no-experimental-sqlite`
 * `--no-experimental-strip-types`
+* `--no-experimental-web-worker`
 * `--no-experimental-websocket`
 * `--no-experimental-webstorage`
-* `--no-experimental-web-worker`
 * `--no-extra-info-on-fatal-exception`
 * `--no-force-async-hooks-checks`
 * `--no-global-search-paths`
diff --git a/doc/node.1 b/doc/node.1
index 0364a938fb10..15296ceb93f0 100644
--- a/doc/node.1
+++ b/doc/node.1
@@ -2087,12 +2087,12 @@ one is included in the list below.
 .It
 \fB--no-experimental-strip-types\fR
 .It
+\fB--no-experimental-web-worker\fR
+.It
 \fB--no-experimental-websocket\fR
 .It
 \fB--no-experimental-webstorage\fR
 .It
-\fB--no-experimental-web-worker\fR
-.It
 \fB--no-extra-info-on-fatal-exception\fR
 .It
 \fB--no-force-async-hooks-checks\fR