ManagedCode.Playwright.Stealth 1.0.0

ManagedCode.Playwright.Stealth (.NET)

ManagedCode.Playwright.Stealth applies a curated set of init scripts to Microsoft.Playwright contexts to reduce common bot-detection signals. It adapts the original playwright_stealth scripts for .NET with ManagedCode conventions.

Install

dotnet add package ManagedCode.Playwright.Stealth

Quick Start

using Microsoft.Playwright;
using ManagedCode.Playwright.Stealth;

using var playwright = await Playwright.CreateAsync();

// One-call launch with stealth args + context pre-configured:
var (browser, context) = await playwright.Chromium.LaunchStealthAsync();

var page = await context.NewPageAsync();
await page.GotoAsync("https://www.browserscan.net/bot-detection");

Manual Setup

If you need more control over launch options:

using var playwright = await Playwright.CreateAsync();
await using var browser = await playwright.Chromium.LaunchAsync(new BrowserTypeLaunchOptions
{
    Headless = true,
    Args = PlaywrightStealthExtensions.StealthArgs // recommended Chrome flags
});

var context = await browser.NewContextAsync();

// Apply stealth before creating pages.
await context.ApplyStealthAsync();

var page = await context.NewPageAsync();
await page.GotoAsync("https://www.browserscan.net/bot-detection");

Configuration

var config = new StealthConfig
{
    NavigatorHardwareConcurrency = 8,
    NavigatorDeviceMemory = 16,
    NavigatorMaxTouchPoints = 1,
    NavigatorUserAgentValue = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
    Vendor = "Intel Inc.",
    Renderer = "Intel Iris OpenGL Engine"
};

await context.ApplyStealthAsync(config);

Apply stealth on a page (if you already have a page instance):

var page = await context.NewPageAsync();
await page.ApplyStealthAsync();
await page.GotoAsync("https://www.browserscan.net/bot-detection");

Disable individual patches:

var config = new StealthConfig
{
    WebDriver = false,
    WebglVendor = false,
    CanvasFingerprint = false,
    AudioContext = false,
    PerformanceJitter = false
};

await context.ApplyStealthAsync(config);

Patched Signals

The default configuration patches 31 detection vectors across these categories:

Navigator Properties

Chrome APIs

Graphics & Rendering

Audio & Media

Window & Screen

Anti-Detection & Timing

DOM & Internals

Public API

Extension Methods

// Apply to browser context (recommended)
await context.ApplyStealthAsync();
await context.ApplyStealthAsync(customConfig);

// Apply to individual page
await page.ApplyStealthAsync();
await page.ApplyStealthAsync(customConfig);

// One-call launch with stealth pre-configured
var (browser, context) = await playwright.Chromium.LaunchStealthAsync();
var (browser, context) = await playwright.Chromium.LaunchStealthAsync(config, launchOptions, contextOptions);

Stealth Chrome Arguments

// Access recommended Chrome args for manual launch setup
string[] args = PlaywrightStealthExtensions.StealthArgs;

Configuration Reference

Toggle Options (bool)

WebDriver, WebglVendor, ChromeApp, ChromeCsi, ChromeLoadTimes, ChromeRuntime, IframeContentWindow, MediaCodecs, Hairline, OuterDimensions, NavigatorLanguages, NavigatorPermissions, NavigatorPlatform, NavigatorPlugins, NavigatorUserAgent, NavigatorVendor, NavigatorConnection, NavigatorPdfViewer, BrokenImage, SpeechSynthesis, ScreenDimensions, CdpDetection, AutomationProperties, CanvasFingerprint, PerformanceJitter, AudioContext

Numeric Options (int)

• NavigatorHardwareConcurrency (default: 4, set 0 to disable)
• NavigatorDeviceMemory (default: 8, set 0 to disable)
• NavigatorMaxTouchPoints (default: 1, set -1 to disable)

String Options

• NavigatorUserAgentValue - Custom user agent string
• NavigatorPlatformValue - Custom platform (e.g., "Win32")
• NavigatorVendorValue - Vendor name (default: "Google Inc.")
• Vendor - WebGL vendor (default: "Intel Inc.")
• Renderer - WebGL renderer (default: "Intel Iris OpenGL Engine")
• Languages - Language array (default: ["en-US", "en"])
• RunOnInsecureOrigins - Allow stealth on http:// origins

Testing

Integration tests target 9 bot-detection sites:

• https://www.browserscan.net/bot-detection
• https://bot.sannysoft.com/
• https://www.intoli.com/blog/not-possible-to-block-chrome-headless/chrome-headless-test.html
• https://fingerprint.com/demo
• https://arh.antoinevastel.com/bots/areyouheadless/
• https://pixelscan.net/bot-check
• https://bot.incolumitas.com/
• https://abrahamjuliot.github.io/creepjs/
• https://deviceandbrowserinfo.com/info_device

These sites can change at any time. If a site changes, update the corresponding test assertions.

Run tests (Playwright browsers install automatically on first run):

dotnet test --solution ManagedCode.Playwright.Stealth.slnx -c Release

On Linux CI runners, set PLAYWRIGHT_INSTALL_DEPS=1 to install system dependencies (playwright install --with-deps) when tests start.

Google search verification is optional (Google may block automated traffic). Enable it with:

RUN_GOOGLE_SEARCH_TESTS=1 dotnet test --solution ManagedCode.Playwright.Stealth.slnx -c Release

Attribution

This project uses code from the original playwright_stealth repository and adapts it for .NET: https://github.com/AtuboDad/playwright_stealth

License

MIT. See LICENSE.