diff --git a/dev-packages/browser-integration-tests/suites/integrations/httpContext-streamed/subject.js b/dev-packages/browser-integration-tests/suites/integrations/httpContext-streamed/subject.js
new file mode 100644
index 000000000000..f1547634fb45
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/httpContext-streamed/subject.js
@@ -0,0 +1,5 @@
+Sentry.startSpan({ name: 'parent-span', op: 'test' }, () => {
+  Sentry.startSpan({ name: 'child-span', op: 'test-child' }, () => {
+    // noop
+  });
+});
diff --git a/dev-packages/browser-integration-tests/suites/integrations/httpContext-streamed/test.ts b/dev-packages/browser-integration-tests/suites/integrations/httpContext-streamed/test.ts
index 9b5563dec995..332ceda450e8 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/httpContext-streamed/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/httpContext-streamed/test.ts
@@ -1,6 +1,7 @@
 import { expect } from '@playwright/test';
 import { sentryTest } from '../../../utils/fixtures';
 import { shouldSkipTracingTest } from '../../../utils/helpers';
+import { URL_FULL, USER_AGENT_ORIGINAL } from '@sentry/conventions/attributes';
 import { getSpanOp, waitForStreamedSpans } from '../../../utils/spanUtils';
 
 sentryTest('httpContextIntegration captures url, user-agent, and referer', async ({ getLocalTestUrl, page }) => {
@@ -15,8 +16,8 @@ sentryTest('httpContextIntegration captures url, user-agent, and referer', async
 
   const pageloadSpan = spans.find(s => getSpanOp(s) === 'pageload');
 
-  expect(pageloadSpan!.attributes['url.full']).toEqual({ type: 'string', value: expect.any(String) });
-  expect(pageloadSpan!.attributes['http.request.header.user_agent']).toEqual({
+  expect(pageloadSpan!.attributes[URL_FULL]).toEqual({ type: 'string', value: expect.any(String) });
+  expect(pageloadSpan!.attributes[USER_AGENT_ORIGINAL]).toEqual({
     type: 'string',
     value: expect.any(String),
   });
@@ -25,3 +26,25 @@ sentryTest('httpContextIntegration captures url, user-agent, and referer', async
     value: 'https://sentry.io/',
   });
 });
+
+sentryTest(
+  'httpContextIntegration only attaches the user agent to non-segment spans',
+  async ({ getLocalTestUrl, page }) => {
+    sentryTest.skip(shouldSkipTracingTest());
+    const url = await getLocalTestUrl({ testDir: __dirname });
+
+    const spansPromise = waitForStreamedSpans(page, spans => spans.some(s => s.name === 'child-span'));
+
+    await page.goto(url, { referer: 'https://sentry.io/' });
+
+    const spans = await spansPromise;
+
+    const childSpan = spans.find(s => s.name === 'child-span');
+
+    expect(childSpan!.is_segment).toBe(false);
+    expect(childSpan!.attributes[USER_AGENT_ORIGINAL]).toEqual({ type: 'string', value: expect.any(String) });
+    // The document URL and referer only belong on the segment span.
+    expect(childSpan!.attributes[URL_FULL]).toBeUndefined();
+    expect(childSpan!.attributes['http.request.header.referer']).toBeUndefined();
+  },
+);
diff --git a/dev-packages/browser-integration-tests/suites/public-api/startSpan/streamed/test.ts b/dev-packages/browser-integration-tests/suites/public-api/startSpan/streamed/test.ts
index c6c85d89bd02..e2a09a658f18 100644
--- a/dev-packages/browser-integration-tests/suites/public-api/startSpan/streamed/test.ts
+++ b/dev-packages/browser-integration-tests/suites/public-api/startSpan/streamed/test.ts
@@ -18,6 +18,7 @@ import {
   SENTRY_SDK_NAME,
   SENTRY_SDK_VERSION,
   SENTRY_TRACE_LIFECYCLE,
+  USER_AGENT_ORIGINAL,
 } from '@sentry/conventions/attributes';
 
 sentryTest(
@@ -107,6 +108,10 @@ sentryTest(
             type: 'string',
             value: 'stream',
           },
+          [USER_AGENT_ORIGINAL]: {
+            type: 'string',
+            value: expect.any(String),
+          },
         },
         end_timestamp: expect.any(Number),
         is_segment: false,
@@ -147,6 +152,10 @@ sentryTest(
             type: 'string',
             value: 'stream',
           },
+          [USER_AGENT_ORIGINAL]: {
+            type: 'string',
+            value: expect.any(String),
+          },
         },
         end_timestamp: expect.any(Number),
         is_segment: false,
@@ -191,6 +200,10 @@ sentryTest(
             type: 'string',
             value: 'stream',
           },
+          [USER_AGENT_ORIGINAL]: {
+            type: 'string',
+            value: expect.any(String),
+          },
         },
         end_timestamp: expect.any(Number),
         is_segment: false,
@@ -215,7 +228,7 @@ sentryTest(
             type: 'string',
             value: expect.any(String),
           },
-          'http.request.header.user_agent': {
+          [USER_AGENT_ORIGINAL]: {
             type: 'string',
             value: expect.any(String),
           },
diff --git a/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/navigation-streamed/test.ts b/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/navigation-streamed/test.ts
index c0ab731ac838..912a72ea6819 100644
--- a/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/navigation-streamed/test.ts
+++ b/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/navigation-streamed/test.ts
@@ -7,7 +7,13 @@ import {
   SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE,
   SEMANTIC_ATTRIBUTE_SENTRY_SDK_INTEGRATIONS,
 } from '@sentry/core';
-import { SENTRY_SEGMENT_NAME_SOURCE, SENTRY_TRACE_LIFECYCLE, URL_FULL, URL_PATH } from '@sentry/conventions/attributes';
+import {
+  SENTRY_SEGMENT_NAME_SOURCE,
+  SENTRY_TRACE_LIFECYCLE,
+  URL_FULL,
+  URL_PATH,
+  USER_AGENT_ORIGINAL,
+} from '@sentry/conventions/attributes';
 import { sentryTest } from '../../../../utils/fixtures';
 import { shouldSkipTracingTest } from '../../../../utils/helpers';
 import {
@@ -87,7 +93,7 @@ sentryTest('starts a streamed navigation span on page navigation', async ({ brow
         type: 'string',
         value: expect.any(String),
       },
-      'http.request.header.user_agent': {
+      [USER_AGENT_ORIGINAL]: {
         type: 'string',
         value: expect.any(String),
       },
diff --git a/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/pageload-streamed/test.ts b/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/pageload-streamed/test.ts
index 999bd1697d82..a16b6839571f 100644
--- a/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/pageload-streamed/test.ts
+++ b/dev-packages/browser-integration-tests/suites/tracing/browserTracingIntegration/pageload-streamed/test.ts
@@ -16,6 +16,7 @@ import {
   SENTRY_TRACE_LIFECYCLE,
   URL_FULL,
   URL_PATH,
+  USER_AGENT_ORIGINAL,
 } from '@sentry/conventions/attributes';
 import { sentryTest } from '../../../../utils/fixtures';
 import { shouldSkipTracingTest } from '../../../../utils/helpers';
@@ -81,7 +82,7 @@ sentryTest(
           type: 'string',
           value: expect.any(String),
         },
-        'http.request.header.user_agent': {
+        [USER_AGENT_ORIGINAL]: {
           type: 'string',
           value: expect.any(String),
         },
diff --git a/dev-packages/browser-integration-tests/suites/tracing/interactions/spans/test.ts b/dev-packages/browser-integration-tests/suites/tracing/interactions/spans/test.ts
index 183210356666..1e8f653607b9 100644
--- a/dev-packages/browser-integration-tests/suites/tracing/interactions/spans/test.ts
+++ b/dev-packages/browser-integration-tests/suites/tracing/interactions/spans/test.ts
@@ -14,6 +14,7 @@ import {
   SENTRY_SDK_NAME,
   SENTRY_SDK_VERSION,
   SENTRY_TRACE_LIFECYCLE,
+  USER_AGENT_ORIGINAL,
 } from '@sentry/conventions/attributes';
 import { sentryTest } from '../../../../utils/fixtures';
 import { shouldSkipTracingTest } from '../../../../utils/helpers';
@@ -61,7 +62,7 @@ sentryTest('captures streamed interaction span tree. @firefox', async ({ browser
         type: 'string',
         value: expect.any(String),
       },
-      'http.request.header.user_agent': {
+      [USER_AGENT_ORIGINAL]: {
         type: 'string',
         value: expect.any(String),
       },
@@ -134,6 +135,10 @@ sentryTest('captures streamed interaction span tree. @firefox', async ({ browser
         type: 'string',
         value: 'ui.interaction.click',
       },
+      [USER_AGENT_ORIGINAL]: {
+        type: 'string',
+        value: expect.any(String),
+      },
       [SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN]: {
         type: 'string',
         value: 'auto.browser.interactions',
diff --git a/dev-packages/e2e-tests/test-applications/nextjs-app-dir/tests/transactions.test.ts b/dev-packages/e2e-tests/test-applications/nextjs-app-dir/tests/transactions.test.ts
index a1a0144f706b..a8645550bbc2 100644
--- a/dev-packages/e2e-tests/test-applications/nextjs-app-dir/tests/transactions.test.ts
+++ b/dev-packages/e2e-tests/test-applications/nextjs-app-dir/tests/transactions.test.ts
@@ -40,7 +40,7 @@ test('Sends a pageload span', async ({ page }) => {
     'url.path': { value: '/', type: 'string' },
     'url.template': { value: '/', type: 'string' },
     'react.version': { value: expect.any(String), type: 'string' },
-    'http.request.header.user_agent': { value: expect.any(String), type: 'string' },
+    'user_agent.original': { value: expect.any(String), type: 'string' },
   });
   expect(String(span.attributes['url.full']?.value)).toMatch(/^https?:\/\/localhost:\d+\/$/);
 });
diff --git a/dev-packages/e2e-tests/test-applications/nextjs-pages-dir/tests/transactions.test.ts b/dev-packages/e2e-tests/test-applications/nextjs-pages-dir/tests/transactions.test.ts
index 7ed43357d430..2212cba2525f 100644
--- a/dev-packages/e2e-tests/test-applications/nextjs-pages-dir/tests/transactions.test.ts
+++ b/dev-packages/e2e-tests/test-applications/nextjs-pages-dir/tests/transactions.test.ts
@@ -34,7 +34,7 @@ test('Sends a pageload span', async ({ page }) => {
     'url.path': { value: '/', type: 'string' },
     'url.template': { value: '/', type: 'string' },
     'react.version': { value: expect.any(String), type: 'string' },
-    'http.request.header.user_agent': { value: expect.any(String), type: 'string' },
+    'user_agent.original': { value: expect.any(String), type: 'string' },
   });
   expect(String(span.attributes['url.full']?.value)).toMatch(/^https?:\/\/localhost:\d+\/$/);
 });
@@ -65,7 +65,7 @@ test('Sends a navigation span', async ({ page }) => {
     'url.path': { value: '/user/5', type: 'string' },
     'url.template': { value: '/user/[id]', type: 'string' },
     'react.version': { value: expect.any(String), type: 'string' },
-    'http.request.header.user_agent': { value: expect.any(String), type: 'string' },
+    'user_agent.original': { value: expect.any(String), type: 'string' },
   });
   expect(String(span.attributes['url.full']?.value)).toMatch(/^https?:\/\/localhost:\d+\/user\/5$/);
 
diff --git a/dev-packages/e2e-tests/test-applications/nitro-3/tests/errors.test.ts b/dev-packages/e2e-tests/test-applications/nitro-3/tests/errors.test.ts
index 1c89b12e1e54..1441ecd5ecab 100644
--- a/dev-packages/e2e-tests/test-applications/nitro-3/tests/errors.test.ts
+++ b/dev-packages/e2e-tests/test-applications/nitro-3/tests/errors.test.ts
@@ -2,8 +2,16 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('Sends an error event to Sentry', async ({ request }) => {
+  // The thrown error is reported twice: once via the h3 tracing channel and once via Nitro's `error`
+  // hook (which sees it wrapped in an `HTTPError`). Match on the mechanism so we deterministically
+  // await the event under test instead of whichever arrives first.
   const errorEventPromise = waitForError('nitro-3', event => {
-    return !event.type && !!event.exception?.values?.some(v => v.value === 'This is a test error');
+    return (
+      !event.type &&
+      !!event.exception?.values?.some(
+        v => v.value === 'This is a test error' && v.mechanism?.type === 'auto.http.nitro.onTraceError',
+      )
+    );
   });
 
   await request.get('/api/test-error').catch(() => {
diff --git a/packages/browser/src/integrations/httpcontext.ts b/packages/browser/src/integrations/httpcontext.ts
index c45f9235793e..8f4c2f957bf8 100644
--- a/packages/browser/src/integrations/httpcontext.ts
+++ b/packages/browser/src/integrations/httpcontext.ts
@@ -1,12 +1,7 @@
-import {
-  _INTERNAL_filterKeyValueData,
-  defineIntegration,
-  safeSetSpanJSONAttributes,
-  SEMANTIC_ATTRIBUTE_SENTRY_OP,
-} from '@sentry/core';
+import { _INTERNAL_filterKeyValueData, defineIntegration, safeSetSpanJSONAttributes } from '@sentry/core';
 import { getHttpRequestData, WINDOW } from '../helpers';
 import { filterCollectedUrl } from '@sentry/core';
-import { URL_FULL } from '@sentry/conventions/attributes';
+import { HTTP_REQUEST_HEADER_KEY_BASE, SENTRY_OP, URL_FULL, USER_AGENT_ORIGINAL } from '@sentry/conventions/attributes';
 
 /**
  * Collects information about HTTP request headers and
@@ -40,9 +35,8 @@ export const httpContextIntegration = defineIntegration(() => {
         ...(Object.keys(headers).length > 0 ? { headers } : { headers: undefined }),
       };
     },
-    processSegmentSpan(span, client) {
-      const spanOp = span.attributes?.[SEMANTIC_ATTRIBUTE_SENTRY_OP];
 
+    processSpan(span, client) {
       // if none of the information we want exists, don't bother
       if (!WINDOW.navigator && !WINDOW.location && !WINDOW.document) {
         return;
@@ -58,11 +52,17 @@ export const httpContextIntegration = defineIntegration(() => {
       );
 
       safeSetSpanJSONAttributes(span, {
-        // Coerce empty string to undefined so the helper's nullish check drops it,
-        // rather than writing an empty `url.full` attribute onto the span.
-        [URL_FULL]: spanOp !== 'http.client' ? filterCollectedUrl(reqData.url) : undefined,
-        'http.request.header.user_agent': headers['User-Agent'],
-        'http.request.header.referer': headers['Referer'],
+        // This attribute is used by the "Filter out events from legacy browsers and crawlers" features on the Sentry backend.
+        // Therefore, it's set on every span.
+        [USER_AGENT_ORIGINAL]: headers['User-Agent'],
+
+        // These attributes, we only need on the segment span (analogous to the `request` context for events)
+        ...(span.is_segment && {
+          // Coerce empty string to undefined so the helper's nullish check drops it,
+          // rather than writing an empty `url.full` attribute onto the span.
+          [URL_FULL]: span.attributes?.[SENTRY_OP] !== 'http.client' ? filterCollectedUrl(reqData.url) : undefined,
+          [`${HTTP_REQUEST_HEADER_KEY_BASE}.referer`]: headers['Referer'],
+        }),
       });
     },
   };
diff --git a/packages/browser/test/integrations/httpcontext.test.ts b/packages/browser/test/integrations/httpcontext.test.ts
index b5af940f5839..a571becfef0a 100644
--- a/packages/browser/test/integrations/httpcontext.test.ts
+++ b/packages/browser/test/integrations/httpcontext.test.ts
@@ -27,6 +27,7 @@ describe('httpContextIntegration', () => {
     const integration = httpContextIntegration();
 
     const span: Partial<StreamedSpanJSON> = {
+      is_segment: true,
       attributes: {
         [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'http.client',
       },
@@ -34,14 +35,13 @@ describe('httpContextIntegration', () => {
 
     const browserClient = new BrowserClient(getDefaultBrowserClientOptions());
 
-    integration.processSegmentSpan!(span as StreamedSpanJSON, browserClient);
+    integration.processSpan!(span as StreamedSpanJSON, browserClient);
 
     expect(span.attributes).not.toHaveProperty('url.full');
     expect(span.attributes).toEqual({
       [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'http.client',
       'http.request.header.referer': 'https://example.com',
-      'http.request.header.user_agent':
-        'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
+      'user_agent.original': USER_AGENT,
     });
   });
 
@@ -49,6 +49,7 @@ describe('httpContextIntegration', () => {
     const integration = httpContextIntegration();
 
     const span: Partial<StreamedSpanJSON> = {
+      is_segment: true,
       attributes: {
         [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'pageload',
       },
@@ -56,17 +57,33 @@ describe('httpContextIntegration', () => {
 
     const browserClient = new BrowserClient(getDefaultBrowserClientOptions());
 
-    integration.processSegmentSpan!(span as StreamedSpanJSON, browserClient);
+    integration.processSpan!(span as StreamedSpanJSON, browserClient);
 
     expect(span.attributes).toEqual({
       [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'pageload',
       'http.request.header.referer': 'https://example.com',
-      'http.request.header.user_agent':
-        'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
+      'user_agent.original': USER_AGENT,
       'url.full': 'https://example.com',
     });
   });
 
+  it('only attaches the user agent to non-segment spans', () => {
+    const integration = httpContextIntegration();
+
+    const span: Partial<StreamedSpanJSON> = {
+      attributes: {
+        [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'ui.click',
+      },
+    };
+
+    integration.processSpan!(span as StreamedSpanJSON, new BrowserClient(getDefaultBrowserClientOptions()));
+
+    expect(span.attributes).toEqual({
+      [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'ui.click',
+      'user_agent.original': USER_AGENT,
+    });
+  });
+
   describe('dataCollection', () => {
     it('attaches headers to events by default', () => {
       const client = new BrowserClient(getDefaultBrowserClientOptions());
@@ -140,10 +157,11 @@ describe('httpContextIntegration', () => {
         getDefaultBrowserClientOptions({ dataCollection: { httpHeaders: { request: false } } }),
       );
       const span: Partial<StreamedSpanJSON> = {
+        is_segment: true,
         attributes: { [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'pageload' },
       };
 
-      httpContextIntegration().processSegmentSpan!(span as StreamedSpanJSON, client);
+      httpContextIntegration().processSpan!(span as StreamedSpanJSON, client);
 
       expect(span.attributes).toEqual({
         [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'pageload',
@@ -156,16 +174,17 @@ describe('httpContextIntegration', () => {
         getDefaultBrowserClientOptions({ dataCollection: { httpHeaders: { request: { deny: ['referer'] } } } }),
       );
       const span: Partial<StreamedSpanJSON> = {
+        is_segment: true,
         attributes: { [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'pageload' },
       };
 
-      httpContextIntegration().processSegmentSpan!(span as StreamedSpanJSON, client);
+      httpContextIntegration().processSpan!(span as StreamedSpanJSON, client);
 
       expect(span.attributes).toEqual({
         [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'pageload',
         'url.full': 'https://example.com',
         'http.request.header.referer': '[Filtered]',
-        'http.request.header.user_agent': USER_AGENT,
+        'user_agent.original': USER_AGENT,
       });
     });
   });