diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5b3b35020083..98fcc5ebcce1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,10 @@
 
 ## Unreleased
 
-- "You miss 100 percent of the chances you don't take. — Wayne Gretzky" — Michael Scott
+- feat(browser): Enable Spotlight via `SENTRY_SPOTLIGHT` env var ([#18050](https://github.com/getsentry/sentry-javascript/pull/18050))
+  - Truthy values (`true`, `t`, `y`, `yes`, `on`, `1`) enable Spotlight with the default URL
+  - Any other non-falsy string value is used as a custom Spotlight Sidecar URL
+  - Falsy values (`false`, `f`, `n`, `no`, `off`, `0`) disable Spotlight
 
 Work in this release was contributed by @hanseo0507. Thank you for your contribution!
 
diff --git a/packages/browser/src/client.ts b/packages/browser/src/client.ts
index 1b4289d66992..263c6d4e4f40 100644
--- a/packages/browser/src/client.ts
+++ b/packages/browser/src/client.ts
@@ -63,6 +63,18 @@ type BrowserSpecificOptions = BrowserClientReplayOptions &
      * @default false
      */
     propagateTraceparent?: boolean;
+
+    /**
+     * If you use Spotlight by Sentry during development, use
+     * this option to forward captured Sentry events to Spotlight.
+     *
+     * Either set it to true, or provide a specific Spotlight Sidecar URL.
+     *
+     * More details: https://spotlightjs.com/
+     *
+     * IMPORTANT: Only set this option to `true` while developing, not in production!
+     */
+    spotlight?: boolean | string;
   };
 /**
  * Configuration options for the Sentry Browser SDK.
diff --git a/packages/browser/src/sdk.ts b/packages/browser/src/sdk.ts
index 7b5d67c636ae..615fbb94b8fb 100644
--- a/packages/browser/src/sdk.ts
+++ b/packages/browser/src/sdk.ts
@@ -1,6 +1,7 @@
 import type { Client, Integration, Options } from '@sentry/core';
 import {
   dedupeIntegration,
+  envToBool,
   functionToStringIntegration,
   getIntegrationsToSetup,
   inboundFiltersIntegration,
@@ -15,6 +16,7 @@ import { browserSessionIntegration } from './integrations/browsersession';
 import { globalHandlersIntegration } from './integrations/globalhandlers';
 import { httpContextIntegration } from './integrations/httpcontext';
 import { linkedErrorsIntegration } from './integrations/linkederrors';
+import { INTEGRATION_NAME as SPOTLIGHT_INTEGRATION_NAME, spotlightBrowserIntegration } from './integrations/spotlight';
 import { defaultStackParser } from './stack-parsers';
 import { makeFetchTransport } from './transports/fetch';
 import { checkAndWarnIfIsEmbeddedBrowserExtension } from './utils/detectBrowserExtension';
@@ -90,6 +92,17 @@ export function init(options: BrowserOptions = {}): Client | undefined {
   const shouldDisableBecauseIsBrowserExtenstion =
     !options.skipBrowserExtensionCheck && checkAndWarnIfIsEmbeddedBrowserExtension();
 
+  // Read spotlight config from env var with graceful fallback
+  // This will be replaced at build time by bundlers like webpack/vite
+  let spotlightFromEnv: boolean | string | undefined;
+  if (typeof process !== 'undefined' && process.env && process.env.SENTRY_SPOTLIGHT !== undefined) {
+    const envValue = process.env.SENTRY_SPOTLIGHT;
+    const parsedEnvValue = envToBool(envValue, { strict: true });
+    spotlightFromEnv = parsedEnvValue ?? envValue;
+  }
+
+  const spotlight = options.spotlight ?? spotlightFromEnv;
+
   const clientOptions: BrowserClientOptions = {
     ...options,
     enabled: shouldDisableBecauseIsBrowserExtenstion ? false : options.enabled,
@@ -100,7 +113,18 @@ export function init(options: BrowserOptions = {}): Client | undefined {
         options.defaultIntegrations == null ? getDefaultIntegrations(options) : options.defaultIntegrations,
     }),
     transport: options.transport || makeFetchTransport,
+    spotlight,
   };
+
+  // Auto-add spotlight integration if enabled and not already present
+  if (spotlight && !clientOptions.integrations.some(({ name }) => name === SPOTLIGHT_INTEGRATION_NAME)) {
+    clientOptions.integrations.push(
+      spotlightBrowserIntegration({
+        sidecarUrl: typeof spotlight === 'string' ? spotlight : undefined,
+      }),
+    );
+  }
+
   return initAndBind(BrowserClient, clientOptions);
 }
 
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index f3b29009b9ce..5718d8deee17 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -313,6 +313,8 @@ export { flushIfServerless } from './utils/flushIfServerless';
 export { SDK_VERSION } from './utils/version';
 export { getDebugImagesForResources, getFilenameToDebugIdMap } from './utils/debug-ids';
 export { escapeStringForRegex } from './vendor/escapeStringForRegex';
+export { envToBool, TRUTHY_ENV_VALUES, FALSY_ENV_VALUES } from './utils/envToBool';
+export type { BoolCastOptions, StrictBoolCast, LooseBoolCast } from './utils/envToBool';
 
 export type { Attachment } from './types-hoist/attachment';
 export type {
diff --git a/packages/node-core/src/utils/envToBool.ts b/packages/core/src/utils/envToBool.ts
similarity index 100%
rename from packages/node-core/src/utils/envToBool.ts
rename to packages/core/src/utils/envToBool.ts
diff --git a/packages/node-core/test/utils/envToBool.test.ts b/packages/core/test/utils/envToBool.test.ts
similarity index 100%
rename from packages/node-core/test/utils/envToBool.test.ts
rename to packages/core/test/utils/envToBool.test.ts
diff --git a/packages/node-core/src/index.ts b/packages/node-core/src/index.ts
index 7557d73c74a2..200855f928ab 100644
--- a/packages/node-core/src/index.ts
+++ b/packages/node-core/src/index.ts
@@ -43,7 +43,6 @@ export { initializeEsmLoader } from './sdk/esmLoader';
 export { isCjs } from './utils/detection';
 export { ensureIsWrapped } from './utils/ensureIsWrapped';
 export { createMissingInstrumentationContext } from './utils/createMissingInstrumentationContext';
-export { envToBool } from './utils/envToBool';
 export { makeNodeTransport, type NodeTransportOptions } from './transports';
 export type { HTTPModuleRequestIncomingMessage } from './transports/http-module';
 export { NodeClient } from './sdk/client';
@@ -112,6 +111,7 @@ export {
   startSession,
   captureSession,
   endSession,
+  envToBool,
   addIntegration,
   startSpan,
   startSpanManual,
diff --git a/packages/node-core/src/sdk/index.ts b/packages/node-core/src/sdk/index.ts
index d53f5d4faefb..24ded762a3e1 100644
--- a/packages/node-core/src/sdk/index.ts
+++ b/packages/node-core/src/sdk/index.ts
@@ -4,6 +4,7 @@ import {
   consoleIntegration,
   consoleSandbox,
   debug,
+  envToBool,
   functionToStringIntegration,
   getCurrentScope,
   getIntegrationsToSetup,
@@ -37,7 +38,6 @@ import { systemErrorIntegration } from '../integrations/systemError';
 import { makeNodeTransport } from '../transports';
 import type { NodeClientOptions, NodeOptions } from '../types';
 import { isCjs } from '../utils/detection';
-import { envToBool } from '../utils/envToBool';
 import { defaultStackParser, getSentryRelease } from './api';
 import { NodeClient } from './client';
 import { initializeEsmLoader } from './esmLoader';