diff --git a/packages/playwright/src/reporters/versions/blobV1.ts b/packages/playwright/src/reporters/versions/blobV1.ts
new file mode 100644
index 0000000000..5ea9350285
--- /dev/null
+++ b/packages/playwright/src/reporters/versions/blobV1.ts
@@ -0,0 +1,127 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { Metadata } from '../../../types/test';
+import type * as reporterTypes from '../../../types/testReporter';
+
+export type JsonLocation = reporterTypes.Location;
+export type JsonError = string;
+export type JsonStackFrame = { file: string, line: number, column: number };
+
+export type JsonStdIOType = 'stdout' | 'stderr';
+
+export type JsonConfig = Pick<reporterTypes.FullConfig, 'configFile' | 'globalTimeout' | 'maxFailures' | 'metadata' | 'rootDir' | 'version' | 'workers'>;
+
+export type JsonPattern = {
+  s?: string;
+  r?: { source: string, flags: string };
+};
+
+export type JsonProject = {
+  grep: JsonPattern[];
+  grepInvert: JsonPattern[];
+  metadata: Metadata;
+  name: string;
+  dependencies: string[];
+  // This is relative to root dir.
+  snapshotDir: string;
+  // This is relative to root dir.
+  outputDir: string;
+  repeatEach: number;
+  retries: number;
+  suites: JsonSuite[];
+  teardown?: string;
+  // This is relative to root dir.
+  testDir: string;
+  testIgnore: JsonPattern[];
+  testMatch: JsonPattern[];
+  timeout: number;
+};
+
+export type JsonSuite = {
+  title: string;
+  location?: JsonLocation;
+  suites: JsonSuite[];
+  tests: JsonTestCase[];
+};
+
+export type JsonTestCase = {
+  testId: string;
+  title: string;
+  location: JsonLocation;
+  retries: number;
+  tags?: string[];
+  repeatEachIndex: number;
+};
+
+export type JsonTestEnd = {
+  testId: string;
+  expectedStatus: reporterTypes.TestStatus;
+  timeout: number;
+  annotations: { type: string, description?: string }[];
+};
+
+export type JsonTestResultStart = {
+  id: string;
+  retry: number;
+  workerIndex: number;
+  parallelIndex: number;
+  startTime: number;
+};
+
+export type JsonAttachment = Omit<reporterTypes.TestResult['attachments'][0], 'body'> & { base64?: string };
+
+export type JsonTestResultEnd = {
+  id: string;
+  duration: number;
+  status: reporterTypes.TestStatus;
+  errors: reporterTypes.TestError[];
+  attachments: JsonAttachment[];
+};
+
+export type JsonTestStepStart = {
+  id: string;
+  parentStepId?: string;
+  title: string;
+  category: string,
+  startTime: number;
+  location?: reporterTypes.Location;
+};
+
+export type JsonTestStepEnd = {
+  id: string;
+  duration: number;
+  error?: reporterTypes.TestError;
+};
+
+export type JsonFullResult = {
+  status: reporterTypes.FullResult['status'];
+  startTime: number;
+  duration: number;
+};
+
+export type JsonEvent = {
+  method: string;
+  params: any
+};
+
+export type BlobReportMetadata = {
+  version: number;
+  userAgent: string;
+  name?: string;
+  shard?: { total: number, current: number };
+  pathSeparator?: string;
+};
diff --git a/tests/assets/blob-1.42.zip b/tests/assets/blob-1.42.zip
new file mode 100644
index 0000000000..da16671ccc
Binary files /dev/null and b/tests/assets/blob-1.42.zip differ
diff --git a/tests/playwright-test/reporter-blob.spec.ts b/tests/playwright-test/reporter-blob.spec.ts
index e12ec3c069..adf1f56ab0 100644
--- a/tests/playwright-test/reporter-blob.spec.ts
+++ b/tests/playwright-test/reporter-blob.spec.ts
@@ -1741,3 +1741,52 @@ test('TestSuite.project() should return owning project', async ({ runInlineTest,
   expect(exitCode).toBe(0);
   expect(output).toContain(`test project: my-project`);
 });
+
+test('open blob-1.42', async ({ runInlineTest, mergeReports }) => {
+  test.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/29984' });
+  await runInlineTest({
+    'echo-reporter.js': `
+      export default class EchoReporter {
+        lines = [];
+        onTestBegin(test) {
+          this.lines.push(test.titlePath().join(' > '));
+        }
+        onEnd() {
+          console.log(this.lines.join('\\n'));
+        }
+      };
+    `,
+    'merge.config.ts': `module.exports = {
+      testDir: 'mergeRoot',
+      reporter: './echo-reporter.js'
+     };`,
+  });
+
+  const blobDir = test.info().outputPath('blob-report');
+  await fs.promises.mkdir(blobDir, { recursive: true });
+  await fs.promises.copyFile(path.join(__dirname, '../assets/blob-1.42.zip'), path.join(blobDir, 'blob-1.42.zip'));
+
+  const { exitCode, output } = await mergeReports(blobDir, undefined, { additionalArgs: ['--config', 'merge.config.ts'] });
+  expect(exitCode).toBe(0);
+  expect(output).toContain(` > chromium > example.spec.ts > test 0
+ > chromium > example.spec.ts > describe 1 > describe 2 > test 3
+ > chromium > example.spec.ts > describe 1 > describe 2 > test 4
+ > chromium > example.spec.ts > describe 1 > describe 2 > test 2
+ > chromium > example.spec.ts > describe 1 > test 1
+ > chromium > example.spec.ts > describe 1 > test 5
+ > chromium > example.spec.ts > test 6
+ > firefox > example.spec.ts > describe 1 > describe 2 > test 2
+ > firefox > example.spec.ts > describe 1 > describe 2 > test 3
+ > firefox > example.spec.ts > test 0
+ > firefox > example.spec.ts > describe 1 > describe 2 > test 4
+ > firefox > example.spec.ts > describe 1 > test 1
+ > firefox > example.spec.ts > test 6
+ > firefox > example.spec.ts > describe 1 > test 5
+ > webkit > example.spec.ts > describe 1 > describe 2 > test 4
+ > webkit > example.spec.ts > test 0
+ > webkit > example.spec.ts > describe 1 > test 1
+ > webkit > example.spec.ts > describe 1 > describe 2 > test 2
+ > webkit > example.spec.ts > describe 1 > describe 2 > test 3
+ > webkit > example.spec.ts > test 6
+ > webkit > example.spec.ts > describe 1 > test 5`);
+});