diff --git a/docs/src/test-reporter-api/class-testcase.md b/docs/src/test-reporter-api/class-testcase.md
index b0df65f432..dbcb3c729d 100644
--- a/docs/src/test-reporter-api/class-testcase.md
+++ b/docs/src/test-reporter-api/class-testcase.md
@@ -27,6 +27,12 @@ Expected test status.
 
 See also [`property: TestResult.status`] for the actual status.
 
+## property: TestCase.id
+* since: v1.25
+- type: <[string]>
+
+Unique test ID that is computed based on the test file name, test title and project name. Test ID can be used as a history ID.
+
 ## property: TestCase.location
 * since: v1.10
 - type: <[Location]>
diff --git a/packages/playwright-test/src/dispatcher.ts b/packages/playwright-test/src/dispatcher.ts
index 8f12892559..17cf36e853 100644
--- a/packages/playwright-test/src/dispatcher.ts
+++ b/packages/playwright-test/src/dispatcher.ts
@@ -27,7 +27,7 @@ export type TestGroup = {
   workerHash: string;
   requireFile: string;
   repeatEachIndex: number;
-  projectIndex: number;
+  projectId: string;
   tests: TestCase[];
 };
 
@@ -67,7 +67,7 @@ export class Dispatcher {
     for (const group of testGroups) {
       this._queuedOrRunningHashCount.set(group.workerHash, 1 + (this._queuedOrRunningHashCount.get(group.workerHash) || 0));
       for (const test of group.tests)
-        this._testById.set(test._id, { test, resultByWorkerIndex: new Map() });
+        this._testById.set(test.id, { test, resultByWorkerIndex: new Map() });
     }
   }
 
@@ -181,7 +181,7 @@ export class Dispatcher {
       doneCallback();
     };
 
-    const remainingByTestId = new Map(testGroup.tests.map(e => [ e._id, e ]));
+    const remainingByTestId = new Map(testGroup.tests.map(e => [ e.id, e ]));
     const failedTestIds = new Set<string>();
 
     const onTestBegin = (params: TestBeginPayload) => {
@@ -298,10 +298,10 @@ export class Dispatcher {
 
       const massSkipTestsFromRemaining = (testIds: Set<string>, errors: TestError[], onlyStartedTests?: boolean) => {
         remaining = remaining.filter(test => {
-          if (!testIds.has(test._id))
+          if (!testIds.has(test.id))
             return true;
           if (!this._hasReachedMaxFailures()) {
-            const data = this._testById.get(test._id)!;
+            const data = this._testById.get(test.id)!;
             const runData = data.resultByWorkerIndex.get(worker.workerIndex);
             // There might be a single test that has started but has not finished yet.
             let result: TestResult;
@@ -317,7 +317,7 @@ export class Dispatcher {
             result.error = result.errors[0];
             result.status = errors.length ? 'failed' : 'skipped';
             this._reportTestEnd(test, result);
-            failedTestIds.add(test._id);
+            failedTestIds.add(test.id);
             errors = []; // Only report errors for the first test.
           }
           return false;
@@ -341,13 +341,13 @@ export class Dispatcher {
       if (params.fatalErrors.length) {
         // In case of fatal errors, report first remaining test as failing with these errors,
         // and all others as skipped.
-        massSkipTestsFromRemaining(new Set(remaining.map(test => test._id)), params.fatalErrors);
+        massSkipTestsFromRemaining(new Set(remaining.map(test => test.id)), params.fatalErrors);
       }
       // Handle tests that should be skipped because of the setup failure.
       massSkipTestsFromRemaining(new Set(params.skipTestsDueToSetupFailure), []);
       // Handle unexpected worker exit.
       if (params.unexpectedExitError)
-        massSkipTestsFromRemaining(new Set(remaining.map(test => test._id)), [params.unexpectedExitError], true /* onlyStartedTests */);
+        massSkipTestsFromRemaining(new Set(remaining.map(test => test.id)), [params.unexpectedExitError], true /* onlyStartedTests */);
 
       const retryCandidates = new Set<string>();
       const serialSuitesWithFailures = new Set<Suite>();
@@ -387,7 +387,7 @@ export class Dispatcher {
         // Add all tests from faiiled serial suites for possible retry.
         // These will only be retried together, because they have the same
         // "retries" setting and the same number of previous runs.
-        serialSuite.allTests().forEach(test => retryCandidates.add(test._id));
+        serialSuite.allTests().forEach(test => retryCandidates.add(test.id));
       }
 
       for (const testId of retryCandidates) {
@@ -527,7 +527,7 @@ class Worker extends EventEmitter {
       workerIndex: this.workerIndex,
       parallelIndex: this.parallelIndex,
       repeatEachIndex: testGroup.repeatEachIndex,
-      projectIndex: testGroup.projectIndex,
+      projectId: testGroup.projectId,
       loader: loaderData,
       stdoutParams: {
         rows: process.stdout.rows,
@@ -547,7 +547,7 @@ class Worker extends EventEmitter {
     const runPayload: RunPayload = {
       file: testGroup.requireFile,
       entries: testGroup.tests.map(test => {
-        return { testId: test._id, retry: test.results.length };
+        return { testId: test.id, retry: test.results.length };
       }),
     };
     this.send({ method: 'run', params: runPayload });
diff --git a/packages/playwright-test/src/ipc.ts b/packages/playwright-test/src/ipc.ts
index 44663a377b..175ef067ef 100644
--- a/packages/playwright-test/src/ipc.ts
+++ b/packages/playwright-test/src/ipc.ts
@@ -34,7 +34,7 @@ export type WorkerInitParams = {
   workerIndex: number;
   parallelIndex: number;
   repeatEachIndex: number;
-  projectIndex: number;
+  projectId: string;
   loader: SerializedLoaderData;
   stdoutParams: TtyParams;
   stderrParams: TtyParams;
diff --git a/packages/playwright-test/src/loader.ts b/packages/playwright-test/src/loader.ts
index f0e8cf5205..827c336ed4 100644
--- a/packages/playwright-test/src/loader.ts
+++ b/packages/playwright-test/src/loader.ts
@@ -152,12 +152,28 @@ export class Loader {
     }
     this._fullConfig.metadata = takeFirst(config.metadata, baseFullConfig.metadata);
     this._fullConfig.projects = (config.projects || [config]).map(p => this._resolveProject(config, this._fullConfig, p, throwawayArtifactsPath));
+    this._assignUniqueProjectIds(this._fullConfig.projects);
+  }
+
+  private _assignUniqueProjectIds(projects: FullProjectInternal[]) {
+    const usedNames = new Set();
+    for (const p of projects) {
+      const name = p.name || '';
+      for (let i = 0; i < projects.length; ++i) {
+        const candidate = name + (i ? i : '');
+        if (usedNames.has(candidate))
+          continue;
+        p._id = candidate;
+        usedNames.add(candidate);
+        break;
+      }
+    }
   }
 
   async loadTestFile(file: string, environment: 'runner' | 'worker') {
     if (cachedFileSuites.has(file))
       return cachedFileSuites.get(file)!;
-    const suite = new Suite(path.relative(this._fullConfig.rootDir, file) || path.basename(file));
+    const suite = new Suite(path.relative(this._fullConfig.rootDir, file) || path.basename(file), 'file');
     suite._requireFile = file;
     suite.location = { file, line: 0, column: 0 };
 
@@ -210,7 +226,7 @@ export class Loader {
 
   buildFileSuiteForProject(project: FullProjectInternal, suite: Suite, repeatEachIndex: number, filter: (test: TestCase) => boolean): Suite | undefined {
     if (!this._projectSuiteBuilders.has(project))
-      this._projectSuiteBuilders.set(project, new ProjectSuiteBuilder(project, this._fullConfig.projects.indexOf(project)));
+      this._projectSuiteBuilders.set(project, new ProjectSuiteBuilder(project));
     const builder = this._projectSuiteBuilders.get(project)!;
     return builder.cloneFileSuite(suite, repeatEachIndex, filter);
   }
@@ -254,6 +270,7 @@ export class Loader {
     const name = takeFirst(projectConfig.name, config.name, '');
     const screenshotsDir = takeFirst((projectConfig as any).screenshotsDir, (config as any).screenshotsDir, path.join(testDir, '__screenshots__', process.platform, name));
     return {
+      _id: '',
       _fullConfig: fullConfig,
       _fullyParallel: takeFirst(projectConfig.fullyParallel, config.fullyParallel, undefined),
       _expect: takeFirst(projectConfig.expect, config.expect, {}),
@@ -307,13 +324,11 @@ export class Loader {
 
 class ProjectSuiteBuilder {
   private _project: FullProjectInternal;
-  private _index: number;
   private _testTypePools = new Map<TestTypeImpl, FixturePool>();
   private _testPools = new Map<TestCase, FixturePool>();
 
-  constructor(project: FullProjectInternal, index: number) {
+  constructor(project: FullProjectInternal) {
     this._project = project;
-    this._index = index;
   }
 
   private _buildTestTypePool(testType: TestTypeImpl): FixturePool {
@@ -337,7 +352,7 @@ class ProjectSuiteBuilder {
 
       for (const parent of parents) {
         if (parent._use.length)
-          pool = new FixturePool(parent._use, pool, parent._isDescribe);
+          pool = new FixturePool(parent._use, pool, parent._type === 'describe');
         for (const hook of parent._hooks)
           pool.validateFunction(hook.fn, hook.type + ' hook', hook.location);
         for (const modifier of parent._modifiers)
@@ -350,32 +365,34 @@ class ProjectSuiteBuilder {
     return this._testPools.get(test)!;
   }
 
-  private _cloneEntries(from: Suite, to: Suite, repeatEachIndex: number, filter: (test: TestCase) => boolean, relativeTitlePath: string): boolean {
+  private _cloneEntries(from: Suite, to: Suite, repeatEachIndex: number, filter: (test: TestCase) => boolean): boolean {
     for (const entry of from._entries) {
       if (entry instanceof Suite) {
         const suite = entry._clone();
+        suite._fileId = to._fileId;
         to._addSuite(suite);
         // Ignore empty titles, similar to Suite.titlePath().
-        const childTitlePath = relativeTitlePath + (suite.title ? ' ' + suite.title : '');
-        if (!this._cloneEntries(entry, suite, repeatEachIndex, filter, childTitlePath)) {
+        if (!this._cloneEntries(entry, suite, repeatEachIndex, filter)) {
           to._entries.pop();
           to.suites.pop();
         }
       } else {
         const test = entry._clone();
-        test.retries = this._project.retries;
-        // We rely upon relative paths being unique.
-        // See `getClashingTestsPerSuite()` in `runner.ts`.
-        test._id = `${calculateSha1(relativeTitlePath + ' ' + entry.title)}@${entry._requireFile}#run${this._index}-repeat${repeatEachIndex}`;
-        test.repeatEachIndex = repeatEachIndex;
-        test._projectIndex = this._index;
         to._addTest(test);
+        test.retries = this._project.retries;
+        const repeatEachIndexSuffix = repeatEachIndex ? ` (repeat:${repeatEachIndex})` : '';
+        // At the point of the query, suite is not yet attached to the project, so we only get file, describe and test titles.
+        const testIdExpression = `[project=${this._project._id}]${test.titlePath().join('\x1e')}${repeatEachIndexSuffix}`;
+        const testId = to._fileId + '-' + calculateSha1(testIdExpression).slice(0, 20);
+        test.id = testId;
+        test.repeatEachIndex = repeatEachIndex;
+        test._projectId = this._project._id;
         if (!filter(test)) {
           to._entries.pop();
           to.tests.pop();
         } else {
           const pool = this._buildPool(entry);
-          test._workerHash = `run${this._index}-${pool.digest}-repeat${repeatEachIndex}`;
+          test._workerHash = `run${this._project._id}-${pool.digest}-repeat${repeatEachIndex}`;
           test._pool = pool;
         }
       }
@@ -387,7 +404,9 @@ class ProjectSuiteBuilder {
 
   cloneFileSuite(suite: Suite, repeatEachIndex: number, filter: (test: TestCase) => boolean): Suite | undefined {
     const result = suite._clone();
-    return this._cloneEntries(suite, result, repeatEachIndex, filter, '') ? result : undefined;
+    const relativeFile = path.relative(this._project.testDir, suite.location!.file).split(path.sep).join('/');
+    result._fileId = calculateSha1(relativeFile).slice(0, 20);
+    return this._cloneEntries(suite, result, repeatEachIndex, filter) ? result : undefined;
   }
 
   private _applyConfigUseOptions(testType: TestTypeImpl, configUse: Fixtures): FixturesWithLocation[] {
@@ -405,7 +424,7 @@ class ProjectSuiteBuilder {
           (originalFixtures as any)[key] = value;
       }
       if (Object.entries(optionsFromConfig).length)
-        result.push({ fixtures: optionsFromConfig, location: { file: `project#${this._index}`, line: 1, column: 1 } });
+        result.push({ fixtures: optionsFromConfig, location: { file: `project#${this._project._id}`, line: 1, column: 1 } });
       if (Object.entries(originalFixtures).length)
         result.push({ fixtures: originalFixtures, location: f.location });
     }
diff --git a/packages/playwright-test/src/reporters/raw.ts b/packages/playwright-test/src/reporters/raw.ts
index 67f994c6f0..4c320c3160 100644
--- a/packages/playwright-test/src/reporters/raw.ts
+++ b/packages/playwright-test/src/reporters/raw.ts
@@ -17,7 +17,7 @@
 import fs from 'fs';
 import path from 'path';
 import type { FullConfig, Location, Suite, TestCase, TestResult, TestStatus, TestStep } from '../../types/testReporter';
-import { assert, calculateSha1 } from 'playwright-core/lib/utils';
+import { assert } from 'playwright-core/lib/utils';
 import { sanitizeForFilePath } from '../util';
 import { formatResultFailure } from './base';
 import { toPosixPath, serializePatterns } from './json';
@@ -180,11 +180,7 @@ class RawReporter {
         timeout: project.timeout,
       },
       suites: suite.suites.map(fileSuite => {
-        // fileId is based on the location of the enclosing file suite.
-        // Don't use the file in test/suite location, it can be different
-        // due to the source map / require.
-        const fileId = calculateSha1(fileSuite.location!.file.split(path.sep).join('/'));
-        return this._serializeSuite(fileSuite, fileId);
+        return this._serializeSuite(fileSuite);
       })
     };
     for (const file of this.stepsInFile.keys()) {
@@ -215,23 +211,21 @@ class RawReporter {
     return report;
   }
 
-  private _serializeSuite(suite: Suite, fileId: string): JsonSuite {
+  private _serializeSuite(suite: Suite): JsonSuite {
     const location = this._relativeLocation(suite.location);
-    return {
+    const result = {
       title: suite.title,
-      fileId,
+      fileId: (suite as any)._fileId,
       location,
-      suites: suite.suites.map(s => this._serializeSuite(s, fileId)),
-      tests: suite.tests.map(t => this._serializeTest(t, fileId)),
+      suites: suite.suites.map(s => this._serializeSuite(s)),
+      tests: suite.tests.map(t => this._serializeTest(t)),
     };
+    return result;
   }
 
-  private _serializeTest(test: TestCase, fileId: string): JsonTestCase {
-    const [, projectName, , ...titles] = test.titlePath();
-    const testIdExpression = `project:${projectName}|path:${titles.join('>')}|repeat:${test.repeatEachIndex}`;
-    const testId = fileId + '-' + calculateSha1(testIdExpression);
+  private _serializeTest(test: TestCase): JsonTestCase {
     return {
-      testId,
+      testId: test.id,
       title: test.title,
       location: this._relativeLocation(test.location)!,
       expectedStatus: test.expectedStatus,
diff --git a/packages/playwright-test/src/runner.ts b/packages/playwright-test/src/runner.ts
index 8d1d2c548a..3aa580ea80 100644
--- a/packages/playwright-test/src/runner.ts
+++ b/packages/playwright-test/src/runner.ts
@@ -266,7 +266,7 @@ export class Runner {
     const fatalErrors: TestError[] = [];
 
     // 1. Add all tests.
-    const preprocessRoot = new Suite('');
+    const preprocessRoot = new Suite('', 'root');
     for (const file of allTestFiles) {
       const fileSuite = await this._loader.loadTestFile(file, 'runner');
       if (fileSuite._loadError)
@@ -299,11 +299,11 @@ export class Runner {
       fileSuites.set(fileSuite._requireFile, fileSuite);
 
     const outputDirs = new Set<string>();
-    const rootSuite = new Suite('');
+    const rootSuite = new Suite('', 'root');
     for (const [project, files] of filesByProject) {
       const grepMatcher = createTitleMatcher(project.grep);
       const grepInvertMatcher = project.grepInvert ? createTitleMatcher(project.grepInvert) : null;
-      const projectSuite = new Suite(project.name);
+      const projectSuite = new Suite(project.name, 'project');
       projectSuite._projectConfig = project;
       if (project._fullyParallel)
         projectSuite._parallelMode = 'parallel';
@@ -671,7 +671,7 @@ function createTestGroups(rootSuite: Suite, workers: number): TestGroup[] {
       workerHash: test._workerHash,
       requireFile: test._requireFile,
       repeatEachIndex: test.repeatEachIndex,
-      projectIndex: test._projectIndex,
+      projectId: test._projectId,
       tests: [],
     };
   };
@@ -794,7 +794,7 @@ function createDuplicateTitlesError(config: FullConfigInternal, rootSuite: Suite
   for (const fileSuite of rootSuite.suites) {
     const testsByFullTitle = new MultiMap<string, TestCase>();
     for (const test of fileSuite.allTests()) {
-      const fullTitle = test.titlePath().slice(2).join(' ');
+      const fullTitle = test.titlePath().slice(2).join('\x1e');
       testsByFullTitle.set(fullTitle, test);
     }
     for (const fullTitle of testsByFullTitle.keys()) {
diff --git a/packages/playwright-test/src/test.ts b/packages/playwright-test/src/test.ts
index 69339d1144..5f50fc2fcc 100644
--- a/packages/playwright-test/src/test.ts
+++ b/packages/playwright-test/src/test.ts
@@ -42,7 +42,6 @@ export class Suite extends Base implements reporterTypes.Suite {
   location?: Location;
   parent?: Suite;
   _use: FixturesWithLocation[] = [];
-  _isDescribe = false;
   _skipped = false;
   _entries: (Suite | TestCase)[] = [];
   _hooks: { type: 'beforeEach' | 'afterEach' | 'beforeAll' | 'afterAll', fn: Function, location: Location }[] = [];
@@ -52,6 +51,13 @@ export class Suite extends Base implements reporterTypes.Suite {
   _parallelMode: 'default' | 'serial' | 'parallel' = 'default';
   _projectConfig: FullProjectInternal | undefined;
   _loadError?: reporterTypes.TestError;
+  _fileId: string | undefined;
+  readonly _type: 'root' | 'project' | 'file' | 'describe';
+
+  constructor(title: string, type: 'root' | 'project' | 'file' | 'describe') {
+    super(title);
+    this._type = type;
+  }
 
   _addTest(test: TestCase) {
     test.parent = this;
@@ -82,7 +88,7 @@ export class Suite extends Base implements reporterTypes.Suite {
   titlePath(): string[] {
     const titlePath = this.parent ? this.parent.titlePath() : [];
     // Ignore anonymous describe blocks.
-    if (this.title || !this._isDescribe)
+    if (this.title || this._type !== 'describe')
       titlePath.push(this.title);
     return titlePath;
   }
@@ -98,7 +104,7 @@ export class Suite extends Base implements reporterTypes.Suite {
   }
 
   _clone(): Suite {
-    const suite = new Suite(this.title);
+    const suite = new Suite(this.title, this._type);
     suite._only = this._only;
     suite.location = this.location;
     suite._requireFile = this._requireFile;
@@ -107,7 +113,6 @@ export class Suite extends Base implements reporterTypes.Suite {
     suite._timeout = this._timeout;
     suite._annotations = this._annotations.slice();
     suite._modifiers = this._modifiers.slice();
-    suite._isDescribe = this._isDescribe;
     suite._parallelMode = this._parallelMode;
     suite._projectConfig = this._projectConfig;
     suite._skipped = this._skipped;
@@ -132,10 +137,10 @@ export class TestCase extends Base implements reporterTypes.TestCase {
   repeatEachIndex = 0;
 
   _testType: TestTypeImpl;
-  _id = '';
+  id = '';
   _workerHash = '';
   _pool: FixturePool | undefined;
-  _projectIndex = 0;
+  _projectId = '';
   // Annotations that are not added from within a test (like fixme and skip), should not
   // be re-added each time we retry a test.
   _alreadyInheritedAnnotations: boolean = false;
diff --git a/packages/playwright-test/src/testInfo.ts b/packages/playwright-test/src/testInfo.ts
index 0dbd7c1dcd..d7c82d37ab 100644
--- a/packages/playwright-test/src/testInfo.ts
+++ b/packages/playwright-test/src/testInfo.ts
@@ -113,20 +113,13 @@ export class TestInfoImpl implements TestInfo {
     this._timeoutManager = new TimeoutManager(this.project.timeout);
 
     this.outputDir = (() => {
-      const sameName = loader.fullConfig().projects.filter(project => project.name === this.project.name);
-      let uniqueProjectNamePathSegment: string;
-      if (sameName.length > 1)
-        uniqueProjectNamePathSegment = this.project.name + (sameName.indexOf(this.project) + 1);
-      else
-        uniqueProjectNamePathSegment = this.project.name;
-
       const relativeTestFilePath = path.relative(this.project.testDir, test._requireFile.replace(/\.(spec|test)\.(js|ts|mjs)$/, ''));
       const sanitizedRelativePath = relativeTestFilePath.replace(process.platform === 'win32' ? new RegExp('\\\\', 'g') : new RegExp('/', 'g'), '-');
       const fullTitleWithoutSpec = test.titlePath().slice(1).join(' ');
 
       let testOutputDir = trimLongString(sanitizedRelativePath + '-' + sanitizeForFilePath(fullTitleWithoutSpec));
-      if (uniqueProjectNamePathSegment)
-        testOutputDir += '-' + sanitizeForFilePath(uniqueProjectNamePathSegment);
+      if (project._id)
+        testOutputDir += '-' + sanitizeForFilePath(project._id);
       if (this.retry)
         testOutputDir += '-retry' + this.retry;
       if (this.repeatEachIndex)
diff --git a/packages/playwright-test/src/testType.ts b/packages/playwright-test/src/testType.ts
index 3c2a932e89..aa9ba2a73f 100644
--- a/packages/playwright-test/src/testType.ts
+++ b/packages/playwright-test/src/testType.ts
@@ -107,9 +107,8 @@ export class TestTypeImpl {
       title = '';
     }
 
-    const child = new Suite(title);
+    const child = new Suite(title, 'describe');
     child._requireFile = suite._requireFile;
-    child._isDescribe = true;
     child.location = location;
     suite._addSuite(child);
 
diff --git a/packages/playwright-test/src/types.ts b/packages/playwright-test/src/types.ts
index eec3f47eac..921a216fb7 100644
--- a/packages/playwright-test/src/types.ts
+++ b/packages/playwright-test/src/types.ts
@@ -59,6 +59,7 @@ export interface FullConfigInternal extends FullConfigPublic {
  * increasing the surface area of the public API type called FullProject.
  */
 export interface FullProjectInternal extends FullProjectPublic {
+  _id: string;
   _fullConfig: FullConfigInternal;
   _fullyParallel: boolean;
   _expect: Project['expect'];
diff --git a/packages/playwright-test/src/worker.ts b/packages/playwright-test/src/worker.ts
index a6d149a98f..a4b96a7ef5 100644
--- a/packages/playwright-test/src/worker.ts
+++ b/packages/playwright-test/src/worker.ts
@@ -27,7 +27,7 @@ sendMessageToParent('ready');
 
 process.stdout.write = (chunk: string | Buffer) => {
   const outPayload: TestOutputPayload = {
-    testId: workerRunner?._currentTest?._test._id,
+    testId: workerRunner?._currentTest?._test.id,
     ...chunkToParams(chunk)
   };
   sendMessageToParent('stdOut', outPayload);
@@ -37,7 +37,7 @@ process.stdout.write = (chunk: string | Buffer) => {
 if (!process.env.PW_RUNNER_DEBUG) {
   process.stderr.write = (chunk: string | Buffer) => {
     const outPayload: TestOutputPayload = {
-      testId: workerRunner?._currentTest?._test._id,
+      testId: workerRunner?._currentTest?._test.id,
       ...chunkToParams(chunk)
     };
     sendMessageToParent('stdErr', outPayload);
diff --git a/packages/playwright-test/src/workerRunner.ts b/packages/playwright-test/src/workerRunner.ts
index 3e0fc66042..b704aca2a4 100644
--- a/packages/playwright-test/src/workerRunner.ts
+++ b/packages/playwright-test/src/workerRunner.ts
@@ -150,7 +150,7 @@ export class WorkerRunner extends EventEmitter {
       return;
 
     this._loader = await Loader.deserialize(this._params.loader);
-    this._project = this._loader.fullConfig().projects[this._params.projectIndex];
+    this._project = this._loader.fullConfig().projects.find(p => p._id === this._params.projectId)!;
   }
 
   async runTestGroup(runPayload: RunPayload) {
@@ -161,7 +161,7 @@ export class WorkerRunner extends EventEmitter {
       await this._loadIfNeeded();
       const fileSuite = await this._loader.loadTestFile(runPayload.file, 'worker');
       const suite = this._loader.buildFileSuiteForProject(this._project, fileSuite, this._params.repeatEachIndex, test => {
-        if (!entries.has(test._id))
+        if (!entries.has(test.id))
           return false;
         return true;
       });
@@ -169,13 +169,13 @@ export class WorkerRunner extends EventEmitter {
         this._extraSuiteAnnotations = new Map();
         this._activeSuites = new Set();
         this._didRunFullCleanup = false;
-        const tests = suite.allTests().filter(test => entries.has(test._id));
+        const tests = suite.allTests().filter(test => entries.has(test.id));
         for (let i = 0; i < tests.length; i++) {
           // Do not run tests after full cleanup, because we are entirely done.
           if (this._isStopped && this._didRunFullCleanup)
             break;
-          const entry = entries.get(tests[i]._id)!;
-          entries.delete(tests[i]._id);
+          const entry = entries.get(tests[i].id)!;
+          entries.delete(tests[i].id);
           await this._runTest(tests[i], entry.retry, tests[i + 1]);
         }
       } else {
@@ -194,8 +194,8 @@ export class WorkerRunner extends EventEmitter {
         fatalUnknownTestIds
       };
       for (const test of this._skipRemainingTestsInSuite?.allTests() || []) {
-        if (entries.has(test._id))
-          donePayload.skipTestsDueToSetupFailure.push(test._id);
+        if (entries.has(test.id))
+          donePayload.skipTestsDueToSetupFailure.push(test.id);
       }
       this.emit('done', donePayload);
       this._fatalErrors = [];
@@ -217,7 +217,7 @@ export class WorkerRunner extends EventEmitter {
           callbackHandled = true;
           const error = result.error instanceof Error ? serializeError(result.error) : result.error;
           const payload: StepEndPayload = {
-            testId: test._id,
+            testId: test.id,
             refinedTitle: step.refinedTitle,
             stepId,
             wallTime: Date.now(),
@@ -230,7 +230,7 @@ export class WorkerRunner extends EventEmitter {
       // Sanitize location that comes from user land, it might have extra properties.
       const location = data.location && hasLocation ? { file: data.location.file, line: data.location.line, column: data.location.column } : undefined;
       const payload: StepBeginPayload = {
-        testId: test._id,
+        testId: test.id,
         stepId,
         ...data,
         location,
@@ -567,14 +567,14 @@ export class WorkerRunner extends EventEmitter {
 
 function buildTestBeginPayload(testInfo: TestInfoImpl): TestBeginPayload {
   return {
-    testId: testInfo._test._id,
+    testId: testInfo._test.id,
     startWallTime: testInfo._startWallTime,
   };
 }
 
 function buildTestEndPayload(testInfo: TestInfoImpl): TestEndPayload {
   return {
-    testId: testInfo._test._id,
+    testId: testInfo._test.id,
     duration: testInfo.duration,
     status: testInfo.status!,
     errors: testInfo.errors,
diff --git a/packages/playwright-test/types/testReporter.d.ts b/packages/playwright-test/types/testReporter.d.ts
index b074712bce..beefad201c 100644
--- a/packages/playwright-test/types/testReporter.d.ts
+++ b/packages/playwright-test/types/testReporter.d.ts
@@ -126,6 +126,12 @@ export interface TestCase {
     description?: string;
   }>;
 
+  /**
+   * Unique test ID that is computed based on the test file name, test title and project name. Test ID can be used as a
+   * history ID.
+   */
+  id: string;
+
   /**
    * Location in the source where the test is defined.
    */
diff --git a/tests/playwright-test/runner.spec.ts b/tests/playwright-test/runner.spec.ts
index becf9ff28d..4e1f73c10d 100644
--- a/tests/playwright-test/runner.spec.ts
+++ b/tests/playwright-test/runner.spec.ts
@@ -31,23 +31,6 @@ test('it should not allow multiple tests with the same name per suite', async ({
   expect(result.output).toContain(`  - tests${path.sep}example.spec.js:7`);
 });
 
-test('it should enforce unique test names based on the describe block name', async ({ runInlineTest }) => {
-  const result = await runInlineTest({
-    'tests/example.spec.js': `
-      const { test } = pwt;
-      test.describe('hello', () => { test('my world', () => {}) });
-      test.describe('hello my', () => { test('world', () => {}) });
-      test('hello my world', () => {});
-    `
-  });
-  expect(result.exitCode).toBe(1);
-  expect(result.output).toContain('duplicate test titles are not allowed');
-  expect(result.output).toContain(`- title: hello my world`);
-  expect(result.output).toContain(`  - tests${path.sep}example.spec.js:6`);
-  expect(result.output).toContain(`  - tests${path.sep}example.spec.js:7`);
-  expect(result.output).toContain(`  - tests${path.sep}example.spec.js:8`);
-});
-
 test('it should not allow multiple tests with the same name in multiple files', async ({ runInlineTest }) => {
   const result = await runInlineTest({
     'tests/example1.spec.js': `
diff --git a/tests/playwright-test/test-output-dir.spec.ts b/tests/playwright-test/test-output-dir.spec.ts
index 0ddc29c511..3749954284 100644
--- a/tests/playwright-test/test-output-dir.spec.ts
+++ b/tests/playwright-test/test-output-dir.spec.ts
@@ -182,15 +182,15 @@ test('should include the project name', async ({ runInlineTest }) => {
   expect(result.output).toContain('my-test.spec.js-snapshots/bar.txt');
 
   // test1, run with foo #1
-  expect(result.output).toContain('test-results/my-test-test-1-foo1/bar.txt');
+  expect(result.output).toContain('test-results/my-test-test-1-foo/bar.txt');
   expect(result.output).toContain('my-test.spec.js-snapshots/bar-foo.txt');
-  expect(result.output).toContain('test-results/my-test-test-1-foo1-retry1/bar.txt');
+  expect(result.output).toContain('test-results/my-test-test-1-foo-retry1/bar.txt');
   expect(result.output).toContain('my-test.spec.js-snapshots/bar-foo.txt');
 
   // test1, run with foo #2
-  expect(result.output).toContain('test-results/my-test-test-1-foo2/bar.txt');
+  expect(result.output).toContain('test-results/my-test-test-1-foo1/bar.txt');
   expect(result.output).toContain('my-test.spec.js-snapshots/bar-foo.txt');
-  expect(result.output).toContain('test-results/my-test-test-1-foo2-retry1/bar.txt');
+  expect(result.output).toContain('test-results/my-test-test-1-foo1-retry1/bar.txt');
   expect(result.output).toContain('my-test.spec.js-snapshots/bar-foo.txt');
 
   // test1, run with bar
@@ -204,11 +204,11 @@ test('should include the project name', async ({ runInlineTest }) => {
   expect(result.output).toContain('my-test.spec.js-snapshots/bar-suffix.txt');
 
   // test2, run with foo #1
-  expect(result.output).toContain('test-results/my-test-test-2-foo1/bar.txt');
+  expect(result.output).toContain('test-results/my-test-test-2-foo/bar.txt');
   expect(result.output).toContain('my-test.spec.js-snapshots/bar-foo-suffix.txt');
 
   // test2, run with foo #2
-  expect(result.output).toContain('test-results/my-test-test-2-foo2/bar.txt');
+  expect(result.output).toContain('test-results/my-test-test-2-foo1/bar.txt');
   expect(result.output).toContain('my-test.spec.js-snapshots/bar-foo-suffix.txt');
 
   // test2, run with bar