diff --git a/packages/playwright-core/src/server/trace/viewer/traceViewer.ts b/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
index 3de6bec1b828f..6b94c0cf485a9 100644
--- a/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
+++ b/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
@@ -105,7 +105,7 @@ export async function startTraceViewerServer(options?: TraceViewerServerOptions)
   return server;
 }
 
-export async function installRootRedirect(server: HttpServer, traceUrls: string[], options: TraceViewerRedirectOptions) {
+export async function installRootRedirect(server: HttpServer, traceUrls: string[], options: TraceViewerRedirectOptions & { resolvedConfigFile?: string }) {
   const params = new URLSearchParams();
   for (const traceUrl of traceUrls)
     params.append('trace', traceUrl);
@@ -115,6 +115,8 @@ export async function installRootRedirect(server: HttpServer, traceUrls: string[
     params.append('isServer', '');
   if (isUnderTest())
     params.append('isUnderTest', 'true');
+  if (options.resolvedConfigFile)
+    params.append('resolvedConfigFile', path.resolve(options.resolvedConfigFile));
   for (const arg of options.args || [])
     params.append('arg', arg);
   if (options.grep)
diff --git a/packages/playwright/src/common/configLoader.ts b/packages/playwright/src/common/configLoader.ts
index 08a9c0a48d09f..de568114a1d0d 100644
--- a/packages/playwright/src/common/configLoader.ts
+++ b/packages/playwright/src/common/configLoader.ts
@@ -286,7 +286,16 @@ function validateProject(file: string, project: Project, title: string) {
   }
 }
 
-export function resolveConfigFile(configFileOrDirectory: string): string | undefined {
+export function resolveConfigLocation(configFile: string | undefined): ConfigLocation {
+  const configFileOrDirectory = configFile ? path.resolve(process.cwd(), configFile) : process.cwd();
+  const resolvedConfigFile = resolveConfigFile(configFileOrDirectory);
+  return {
+    resolvedConfigFile,
+    configDir: resolvedConfigFile ? path.dirname(resolvedConfigFile) : configFileOrDirectory,
+  };
+}
+
+function resolveConfigFile(configFileOrDirectory: string): string | undefined {
   const resolveConfig = (configFile: string) => {
     if (fs.existsSync(configFile))
       return configFile;
@@ -309,22 +318,15 @@ export function resolveConfigFile(configFileOrDirectory: string): string | undef
       return configFile;
     // If there is no config, assume this as a root testing directory.
     return undefined;
-  } else {
-    // When passed a file, it must be a config file.
-    const configFile = resolveConfig(configFileOrDirectory);
-    return configFile!;
   }
+  // When passed a file, it must be a config file.
+  return configFileOrDirectory!;
 }
 
 export async function loadConfigFromFileRestartIfNeeded(configFile: string | undefined, overrides?: ConfigCLIOverrides, ignoreDeps?: boolean): Promise<FullConfigInternal | null> {
-  const configFileOrDirectory = configFile ? path.resolve(process.cwd(), configFile) : process.cwd();
-  const resolvedConfigFile = resolveConfigFile(configFileOrDirectory);
-  if (restartWithExperimentalTsEsm(resolvedConfigFile))
+  const location = resolveConfigLocation(configFile);
+  if (restartWithExperimentalTsEsm(location.resolvedConfigFile))
     return null;
-  const location: ConfigLocation = {
-    configDir: resolvedConfigFile ? path.dirname(resolvedConfigFile) : configFileOrDirectory,
-    resolvedConfigFile,
-  };
   return await loadConfig(location, overrides, ignoreDeps);
 }
 
diff --git a/packages/playwright/src/runner/testServer.ts b/packages/playwright/src/runner/testServer.ts
index da1584de967a3..c483d8c57ed0a 100644
--- a/packages/playwright/src/runner/testServer.ts
+++ b/packages/playwright/src/runner/testServer.ts
@@ -21,7 +21,7 @@ import { ManualPromise, gracefullyProcessExitDoNotHang, isUnderTest } from 'play
 import type { Transport, HttpServer } from 'playwright-core/lib/utils';
 import type * as reporterTypes from '../../types/testReporter';
 import { collectAffectedTestFiles, dependenciesForTestFile } from '../transform/compilationCache';
-import type { FullConfigInternal } from '../common/config';
+import type { ConfigLocation, FullConfigInternal } from '../common/config';
 import { InternalReporter } from '../reporters/internalReporter';
 import { createReporterForTestServer, createReporters } from './reporters';
 import { TestRun, createTaskRunnerForList, createTaskRunnerForTestServer, createTaskRunnerForWatchSetup, createTaskRunnerForListFiles } from './tasks';
@@ -33,7 +33,7 @@ import { Watcher } from '../fsWatcher';
 import type { ReportEntry, TestServerInterface, TestServerInterfaceEventEmitters } from '../isomorphic/testServerInterface';
 import { Runner } from './runner';
 import type { ConfigCLIOverrides } from '../common/ipc';
-import { loadConfig, resolveConfigFile, restartWithExperimentalTsEsm } from '../common/configLoader';
+import { loadConfig, resolveConfigLocation, restartWithExperimentalTsEsm } from '../common/configLoader';
 import { webServerPluginsForConfig } from '../plugins/webServerPlugin';
 import type { TraceViewerRedirectOptions, TraceViewerServerOptions } from 'playwright-core/lib/server/trace/viewer/traceViewer';
 import type { TestRunnerPluginRegistration } from '../plugins';
@@ -44,15 +44,15 @@ const originalStdoutWrite = process.stdout.write;
 const originalStderrWrite = process.stderr.write;
 
 class TestServer {
-  private _configFile: string | undefined;
+  private _configLocation: ConfigLocation;
   private _dispatcher: TestServerDispatcher | undefined;
 
-  constructor(configFile: string | undefined) {
-    this._configFile = configFile;
+  constructor(configLocation: ConfigLocation) {
+    this._configLocation = configLocation;
   }
 
   async start(options: { host?: string, port?: number }): Promise<HttpServer> {
-    this._dispatcher = new TestServerDispatcher(this._configFile);
+    this._dispatcher = new TestServerDispatcher(this._configLocation);
     return await startTraceViewerServer({ ...options, transport: this._dispatcher.transport });
   }
 
@@ -63,7 +63,7 @@ class TestServer {
 }
 
 class TestServerDispatcher implements TestServerInterface {
-  private _configFile: string | undefined;
+  private _configLocation: ConfigLocation;
   private _globalWatcher: Watcher;
   private _testWatcher: Watcher;
   private _testRun: { run: Promise<reporterTypes.FullResult['status']>, stop: ManualPromise<void> } | undefined;
@@ -77,8 +77,8 @@ class TestServerDispatcher implements TestServerInterface {
   private _closeOnDisconnect = false;
   private _devServerHandle: (() => Promise<void>) | undefined;
 
-  constructor(configFile: string | undefined) {
-    this._configFile = configFile;
+  constructor(configLocation: ConfigLocation) {
+    this._configLocation = configLocation;
     this.transport = {
       dispatch: (method, params) => (this as any)[method](params),
       onclose: () => {
@@ -145,7 +145,7 @@ class TestServerDispatcher implements TestServerInterface {
     await this.runGlobalTeardown();
 
     const { reporter, report } = await this._collectingReporter();
-    const { config, error } = await this._loadConfig(this._configFile);
+    const { config, error } = await this._loadConfig();
     if (!config) {
       reporter.onError(error!);
       return { status: 'failed', report };
@@ -178,7 +178,7 @@ class TestServerDispatcher implements TestServerInterface {
     if (this._devServerHandle)
       return { status: 'failed', report: [] };
     const { reporter, report } = await this._collectingReporter();
-    const { config, error } = await this._loadConfig(this._configFile);
+    const { config, error } = await this._loadConfig();
     if (!config) {
       reporter.onError(error!);
       return { status: 'failed', report };
@@ -212,14 +212,14 @@ class TestServerDispatcher implements TestServerInterface {
   }
 
   async clearCache(params: Parameters<TestServerInterface['clearCache']>[0]): ReturnType<TestServerInterface['clearCache']> {
-    const { config } = await this._loadConfig(this._configFile);
+    const { config } = await this._loadConfig();
     if (config)
       await clearCacheAndLogToConsole(config);
   }
 
   async listFiles(params: Parameters<TestServerInterface['listFiles']>[0]): ReturnType<TestServerInterface['listFiles']> {
     const { reporter, report } = await this._collectingReporter();
-    const { config, error } = await this._loadConfig(this._configFile);
+    const { config, error } = await this._loadConfig();
     if (!config) {
       reporter.onError(error!);
       return { status: 'failed', report };
@@ -250,7 +250,7 @@ class TestServerDispatcher implements TestServerInterface {
       retries: 0,
     };
     const { reporter, report } = await this._collectingReporter();
-    const { config, error } = await this._loadConfig(this._configFile, overrides);
+    const { config, error } = await this._loadConfig(overrides);
     if (!config) {
       reporter.onError(error!);
       return { report: [], status: 'failed' };
@@ -315,7 +315,7 @@ class TestServerDispatcher implements TestServerInterface {
     else
       process.env.PW_LIVE_TRACE_STACKS = undefined;
 
-    const { config, error } = await this._loadConfig(this._configFile, overrides);
+    const { config, error } = await this._loadConfig(overrides);
     if (!config) {
       const wireReporter = await this._wireReporter(e => this._dispatchEvent('report', e));
       wireReporter.onError(error!);
@@ -359,7 +359,7 @@ class TestServerDispatcher implements TestServerInterface {
   }
 
   async findRelatedTestFiles(params: Parameters<TestServerInterface['findRelatedTestFiles']>[0]): ReturnType<TestServerInterface['findRelatedTestFiles']> {
-    const { config, error } = await this._loadConfig(this._configFile);
+    const { config, error } = await this._loadConfig();
     if (error)
       return { testFiles: [], errors: [error] };
     const runner = new Runner(config!);
@@ -393,11 +393,9 @@ class TestServerDispatcher implements TestServerInterface {
     gracefullyProcessExitDoNotHang(0);
   }
 
-  private async _loadConfig(configFile: string | undefined, overrides?: ConfigCLIOverrides): Promise<{ config: FullConfigInternal | null, error?: reporterTypes.TestError }> {
-    const configFileOrDirectory = configFile ? path.resolve(process.cwd(), configFile) : process.cwd();
-    const resolvedConfigFile = resolveConfigFile(configFileOrDirectory);
+  private async _loadConfig(overrides?: ConfigCLIOverrides): Promise<{ config: FullConfigInternal | null, error?: reporterTypes.TestError }> {
     try {
-      const config = await loadConfig({ resolvedConfigFile, configDir: resolvedConfigFile === configFileOrDirectory ? path.dirname(resolvedConfigFile) : configFileOrDirectory  }, overrides);
+      const config = await loadConfig(this._configLocation, overrides);
       // Preserve plugin instances between setup and build.
       if (!this._plugins)
         this._plugins = config.plugins || [];
@@ -411,8 +409,8 @@ class TestServerDispatcher implements TestServerInterface {
 }
 
 export async function runUIMode(configFile: string | undefined, options: TraceViewerServerOptions & TraceViewerRedirectOptions): Promise<reporterTypes.FullResult['status'] | 'restarted'> {
-  return await innerRunTestServer(configFile, options, async (server: HttpServer, cancelPromise: ManualPromise<void>) => {
-    await installRootRedirect(server, [], { ...options, webApp: 'uiMode.html' });
+  return await innerRunTestServer(configFile, options, async (server: HttpServer, cancelPromise: ManualPromise<void>, configLocation: ConfigLocation) => {
+    await installRootRedirect(server, [], { ...options, webApp: 'uiMode.html', resolvedConfigFile: configLocation.resolvedConfigFile });
     if (options.host !== undefined || options.port !== undefined) {
       await openTraceInBrowser(server.urlPrefix());
     } else {
@@ -434,17 +432,18 @@ export async function runTestServer(configFile: string | undefined, options: { h
   });
 }
 
-async function innerRunTestServer(configFile: string | undefined, options: { host?: string, port?: number }, openUI: (server: HttpServer, cancelPromise: ManualPromise<void>) => Promise<void>): Promise<reporterTypes.FullResult['status'] | 'restarted'> {
+async function innerRunTestServer(configFile: string | undefined, options: { host?: string, port?: number }, openUI: (server: HttpServer, cancelPromise: ManualPromise<void>, configLocation: ConfigLocation) => Promise<void>): Promise<reporterTypes.FullResult['status'] | 'restarted'> {
   if (restartWithExperimentalTsEsm(undefined, true))
     return 'restarted';
-  const testServer = new TestServer(configFile);
+  const configLocation = resolveConfigLocation(configFile);
+  const testServer = new TestServer(configLocation);
   const cancelPromise = new ManualPromise<void>();
   const sigintWatcher = new SigIntWatcher();
   process.stdin.on('close', () => gracefullyProcessExitDoNotHang(0));
   void sigintWatcher.promise().then(() => cancelPromise.resolve());
   try {
     const server = await testServer.start(options);
-    await openUI(server, cancelPromise);
+    await openUI(server, cancelPromise, configLocation);
     await cancelPromise;
   } finally {
     await testServer.stop();
diff --git a/packages/trace-viewer/src/ui/uiModeFiltersView.tsx b/packages/trace-viewer/src/ui/uiModeFiltersView.tsx
index a6cff6ecf8025..0964620511bc6 100644
--- a/packages/trace-viewer/src/ui/uiModeFiltersView.tsx
+++ b/packages/trace-viewer/src/ui/uiModeFiltersView.tsx
@@ -20,7 +20,6 @@ import '@web/third_party/vscode/codicon.css';
 import { settings } from '@web/uiUtils';
 import React from 'react';
 import './uiModeFiltersView.css';
-import type { TestModel } from './uiModeModel';
 
 export const FiltersView: React.FC<{
   filterText: string;
@@ -29,9 +28,9 @@ export const FiltersView: React.FC<{
   setStatusFilters: (filters: Map<string, boolean>) => void;
   projectFilters: Map<string, boolean>;
   setProjectFilters: (filters: Map<string, boolean>) => void;
-  testModel: TestModel | undefined,
+  resolvedConfigFile: string | undefined,
   runTests: () => void;
-}> = ({ filterText, setFilterText, statusFilters, setStatusFilters, projectFilters, setProjectFilters, testModel, runTests }) => {
+}> = ({ filterText, setFilterText, statusFilters, setStatusFilters, projectFilters, setProjectFilters, resolvedConfigFile, runTests }) => {
   const [expanded, setExpanded] = React.useState(false);
   const inputRef = React.useRef<HTMLInputElement>(null);
   React.useEffect(() => {
@@ -80,9 +79,8 @@ export const FiltersView: React.FC<{
                 const copy = new Map(projectFilters);
                 copy.set(projectName, !copy.get(projectName));
                 setProjectFilters(copy);
-                const configFile = testModel?.config?.configFile;
-                if (configFile)
-                  settings.setObject(configFile + ':projects', [...copy.entries()].filter(([_, v]) => v).map(([k]) => k));
+                if (resolvedConfigFile)
+                  settings.setObject(resolvedConfigFile + ':projects', [...copy.entries()].filter(([_, v]) => v).map(([k]) => k));
               }}/>
               <div>{projectName || 'untitled'}</div>
             </label>
diff --git a/packages/trace-viewer/src/ui/uiModeView.tsx b/packages/trace-viewer/src/ui/uiModeView.tsx
index 03abb468ab6df..7daf2eb9680bf 100644
--- a/packages/trace-viewer/src/ui/uiModeView.tsx
+++ b/packages/trace-viewer/src/ui/uiModeView.tsx
@@ -53,6 +53,7 @@ const guid = searchParams.get('ws');
 const wsURL = new URL(`../${guid}`, window.location.toString());
 wsURL.protocol = (window.location.protocol === 'https:' ? 'wss:' : 'ws:');
 const queryParams = {
+  resolvedConfigFile: searchParams.get('resolvedConfigFile') || undefined,
   args: searchParams.getAll('arg'),
   grep: searchParams.get('grep') || undefined,
   grepInvert: searchParams.get('grepInvert') || undefined,
@@ -201,8 +202,8 @@ export const UIModeView: React.FC<{}> = ({
     if (!testModel)
       return;
 
-    const { config, rootSuite } = testModel;
-    const selectedProjects = config.configFile ? settings.getObject<string[] | undefined>(config.configFile + ':projects', undefined) : undefined;
+    const { rootSuite } = testModel;
+    const selectedProjects = queryParams.resolvedConfigFile ? settings.getObject<string[] | undefined>(queryParams.resolvedConfigFile + ':projects', undefined) : undefined;
     const newFilter = new Map(projectFilters);
     for (const projectName of newFilter.keys()) {
       if (!rootSuite.suites.find(s => s.title === projectName))
@@ -411,7 +412,7 @@ export const UIModeView: React.FC<{}> = ({
           setStatusFilters={setStatusFilters}
           projectFilters={projectFilters}
           setProjectFilters={setProjectFilters}
-          testModel={testModel}
+          resolvedConfigFile={queryParams.resolvedConfigFile}
           runTests={() => runTests('bounce-if-busy', visibleTestIds)} />
         <Toolbar noMinHeight={true}>
           {!isRunningTest && !progress && <div className='section-title'>Tests</div>}