diff --git a/packages/playwright-test/src/isomorphic/teleReceiver.ts b/packages/playwright-test/src/isomorphic/teleReceiver.ts
index 8a99bf6f58..8b961806de 100644
--- a/packages/playwright-test/src/isomorphic/teleReceiver.ts
+++ b/packages/playwright-test/src/isomorphic/teleReceiver.ts
@@ -88,12 +88,14 @@ export type JsonTestResultStart = {
   startTime: string;
 };
 
+export type JsonAttachment = Omit<TestResult['attachments'][0], 'body'> & { base64?: string };
+
 export type JsonTestResultEnd = {
   id: string;
   duration: number;
   status: TestStatus;
   errors: TestError[];
-  attachments: TestResult['attachments'];
+  attachments: JsonAttachment[];
 };
 
 export type JsonTestStepStart = {
@@ -228,7 +230,7 @@ export class TeleReporterReceiver {
     result.status = payload.status;
     result.statusEx = payload.status;
     result.errors = payload.errors;
-    result.attachments = payload.attachments;
+    result.attachments = this._parseAttachments(payload.attachments);
     this._reporter.onTestEnd?.(test, result);
   }
 
@@ -321,6 +323,15 @@ export class TeleReporterReceiver {
     };
   }
 
+  private _parseAttachments(attachments: JsonAttachment[]): TestResult['attachments'] {
+    return attachments.map(a => {
+      return {
+        ...a,
+        body: a.base64 && (globalThis as any).Buffer ? Buffer.from(a.base64, 'base64') : undefined,
+      };
+    });
+  }
+
   private _mergeSuitesInto(jsonSuites: JsonSuite[], parent: TeleSuite) {
     for (const jsonSuite of jsonSuites) {
       let targetSuite = parent.suites.find(s => s.title === jsonSuite.title);
diff --git a/packages/playwright-test/src/reporters/blob.ts b/packages/playwright-test/src/reporters/blob.ts
index 36a27270b1..115d8008d8 100644
--- a/packages/playwright-test/src/reporters/blob.ts
+++ b/packages/playwright-test/src/reporters/blob.ts
@@ -21,7 +21,7 @@ import { mime } from 'playwright-core/lib/utilsBundle';
 import { Readable } from 'stream';
 import type { FullConfig, FullResult, TestResult } from '../../types/testReporter';
 import type { Suite } from '../common/test';
-import type { JsonEvent } from '../isomorphic/teleReceiver';
+import type { JsonAttachment, JsonEvent } from '../isomorphic/teleReceiver';
 import { TeleReporterEmitter } from './teleEmitter';
 
 
@@ -44,7 +44,7 @@ export class BlobReporter extends TeleReporterEmitter {
   private _reportFile!: string;
 
   constructor(options: BlobReporterOptions) {
-    super(message => this._messages.push(message));
+    super(message => this._messages.push(message), false);
     this._options = options;
     this._salt = createGuid();
 
@@ -78,8 +78,8 @@ export class BlobReporter extends TeleReporterEmitter {
     ]);
   }
 
-  override _serializeAttachments(attachments: TestResult['attachments']): TestResult['attachments'] {
-    return attachments.map(attachment => {
+  override _serializeAttachments(attachments: TestResult['attachments']): JsonAttachment[] {
+    return super._serializeAttachments(attachments).map(attachment => {
       if (!attachment.path || !fs.statSync(attachment.path).isFile())
         return attachment;
       // Add run guid to avoid clashes between shards.
diff --git a/packages/playwright-test/src/reporters/teleEmitter.ts b/packages/playwright-test/src/reporters/teleEmitter.ts
index 3a3eceac2c..fd93498ce6 100644
--- a/packages/playwright-test/src/reporters/teleEmitter.ts
+++ b/packages/playwright-test/src/reporters/teleEmitter.ts
@@ -20,15 +20,17 @@ import type { SuitePrivate } from '../../types/reporterPrivate';
 import type { FullConfig, FullResult, Location, Reporter, TestError, TestResult, TestStep } from '../../types/testReporter';
 import { FullConfigInternal, FullProjectInternal } from '../common/config';
 import type { Suite, TestCase } from '../common/test';
-import type { JsonConfig, JsonEvent, JsonProject, JsonStdIOType, JsonSuite, JsonTestCase, JsonTestEnd, JsonTestResultEnd, JsonTestResultStart, JsonTestStepEnd, JsonTestStepStart } from '../isomorphic/teleReceiver';
+import type { JsonAttachment, JsonConfig, JsonEvent, JsonProject, JsonStdIOType, JsonSuite, JsonTestCase, JsonTestEnd, JsonTestResultEnd, JsonTestResultStart, JsonTestStepEnd, JsonTestStepStart } from '../isomorphic/teleReceiver';
 import { serializeRegexPatterns } from '../isomorphic/teleReceiver';
 
 export class TeleReporterEmitter implements Reporter {
   private _messageSink: (message: JsonEvent) => void;
   private _rootDir!: string;
+  private _receiverIsInBrowser: boolean;
 
-  constructor(messageSink: (message: JsonEvent) => void) {
+  constructor(messageSink: (message: JsonEvent) => void, receiverIsInBrowser: boolean) {
     this._messageSink = messageSink;
+    this._receiverIsInBrowser = receiverIsInBrowser;
   }
 
   onBegin(config: FullConfig, suite: Suite) {
@@ -199,8 +201,14 @@ export class TeleReporterEmitter implements Reporter {
     };
   }
 
-  _serializeAttachments(attachments: TestResult['attachments']): TestResult['attachments'] {
-    return attachments;
+  _serializeAttachments(attachments: TestResult['attachments']): JsonAttachment[] {
+    return attachments.map(a => {
+      return {
+        ...a,
+        // There is no Buffer in the browser, so there is no point in sending the data there.
+        base64: (a.body && !this._receiverIsInBrowser) ? a.body.toString('base64') : undefined,
+      };
+    });
   }
 
   private _serializeStepStart(step: TestStep): JsonTestStepStart {
diff --git a/packages/playwright-test/src/runner/uiMode.ts b/packages/playwright-test/src/runner/uiMode.ts
index a800a94d8b..a07738edb9 100644
--- a/packages/playwright-test/src/runner/uiMode.ts
+++ b/packages/playwright-test/src/runner/uiMode.ts
@@ -158,7 +158,7 @@ class UIMode {
   }
 
   private async _listTests() {
-    const listReporter = new TeleReporterEmitter(e => this._dispatchEvent(e.method, e.params));
+    const listReporter = new TeleReporterEmitter(e => this._dispatchEvent(e.method, e.params), true);
     const reporter = new InternalReporter([listReporter]);
     this._config.cliListOnly = true;
     this._config.testIdMatcher = undefined;
@@ -183,7 +183,7 @@ class UIMode {
     this._config.testIdMatcher = id => !testIdSet || testIdSet.has(id);
 
     const reporters = await createReporters(this._config, 'ui');
-    reporters.push(new TeleReporterEmitter(e => this._dispatchEvent(e.method, e.params)));
+    reporters.push(new TeleReporterEmitter(e => this._dispatchEvent(e.method, e.params), true));
     const reporter = new InternalReporter(reporters);
     const taskRunner = createTaskRunnerForWatch(this._config, reporter);
     const testRun = new TestRun(this._config, reporter);
diff --git a/tests/playwright-test/reporter-blob.spec.ts b/tests/playwright-test/reporter-blob.spec.ts
index 32d3226b23..b328ad2ce2 100644
--- a/tests/playwright-test/reporter-blob.spec.ts
+++ b/tests/playwright-test/reporter-blob.spec.ts
@@ -947,6 +947,59 @@ result.stderr: stderr text
 `);
 });
 
+test('encode inline attachments', async ({ runInlineTest, mergeReports }) => {
+  const reportDir = test.info().outputPath('blob-report');
+  const files = {
+    'echo-reporter.js': `
+      import fs from 'fs';
+
+      class EchoReporter {
+        onTestEnd(test, result) {
+          const attachmentBodies = result.attachments.map(a => a.body?.toString('base64'));
+          result.attachments.forEach(a => console.log(a.body, 'isBuffer', Buffer.isBuffer(a.body)));
+          fs.writeFileSync('log.txt', attachmentBodies.join(','));
+        }
+      }
+      module.exports = EchoReporter;
+    `,
+    'playwright.config.js': `
+      module.exports = {
+        reporter: [['blob']]
+      };
+    `,
+    'a.test.js': `
+      import { test, expect } from '@playwright/test';
+      test('a test', async ({}) => {
+        expect(1 + 1).toBe(2);
+        test.info().attachments.push({
+          name: 'example.txt',
+          contentType: 'text/plain',
+          body: Buffer.from('foo'),
+        });
+
+        test.info().attachments.push({
+          name: 'example.json',
+          contentType: 'application/json',
+          body: Buffer.from(JSON.stringify({ foo: 1 })),
+        });
+
+        test.info().attachments.push({
+          name: 'example-utf16.txt',
+          contentType: 'text/plain, charset=utf16le',
+          body: Buffer.from('utf16 encoded', 'utf16le'),
+        });
+      });
+    `,
+  };
+
+  await runInlineTest(files);
+
+  const { exitCode } = await mergeReports(reportDir, {}, { additionalArgs: ['--reporter', test.info().outputPath('echo-reporter.js')] });
+  expect(exitCode).toBe(0);
+  const log = fs.readFileSync(test.info().outputPath('log.txt')).toString();
+  expect(log).toBe(`Zm9v,eyJmb28iOjF9,dQB0AGYAMQA2ACAAZQBuAGMAbwBkAGUAZAA=`);
+});
+
 test('preserve steps in html report', async ({ runInlineTest, mergeReports, showReport, page }) => {
   const reportDir = test.info().outputPath('blob-report');
   const files = {