Noise Seed Reproducibility

Deterministic noise generation with seed control for reproducible fingerprint protection across sessions.

Prerequisites

• BotBrowser installed. See Installation Guide.
• A profile file (.enc for production).

Quick Start

chromium-browser \
  --bot-profile="/path/to/profile.enc"

Start with this launch to establish a clean baseline before adding extra overrides.

How It Works

BotBrowser applies controlled noise to fingerprint surfaces like Canvas, WebGL, AudioContext, and text measurements to prevent cross-session correlation. The --bot-noise-seed flag (ENT Tier2) gives you deterministic control over this noise: the same seed always produces the same fingerprint, while different seeds produce distinct identities.

What Is a Noise Seed?

A noise seed is an integer value that initializes BotBrowser’s deterministic random number generator. This generator controls the variance applied to fingerprint-sensitive APIs. Because the RNG is seeded, the output is reproducible: identical inputs with the same seed always produce identical outputs.

# Set a noise seed for deterministic fingerprinting
chromium-browser \
  --bot-profile="/path/to/profile.enc" \
  --bot-noise-seed=42

Key properties:

• Same seed = same fingerprint. A session launched with --bot-noise-seed=42 produces identical Canvas hashes, WebGL readbacks, and audio fingerprints every time.
• Different seed = different fingerprint. Changing the seed to 43 produces a completely different but equally stable identity.
• Seed value 0 keeps noise active using profile defaults (no deterministic seeding).

Seed Range

The --bot-noise-seed flag accepts integer values from 1 to UINT32_MAX (4,294,967,295). Each value produces a unique, stable noise pattern.

Affected Fingerprint Surfaces

The noise seed controls variance across all major fingerprint surfaces:

The seed controls noise across Canvas 2D, WebGL, WebGPU, AudioContext, ClientRects, and TextRects. All rendering and measurement output from these surfaces remains consistent per seed across sessions and restarts.

Per-Context Noise Seed

When using per-context fingerprinting (ENT Tier3), each BrowserContext can have its own noise seed. This allows multiple isolated identities within a single browser process, each with deterministic and independent noise.

// Puppeteer
// Browser-level CDP session (required for BotBrowser.* commands)
const client = await browser.target().createCDPSession();
 
// Create a new browser context BEFORE setting flags
const context = await browser.createBrowserContext();
 
// Set per-context flags BEFORE creating any page
await client.send("BotBrowser.setBrowserContextFlags", {
  browserContextId: context._contextId,
  botbrowserFlags: [
    "--bot-profile=/path/to/profile-a.enc",
    "--bot-noise-seed=100",
  ],
});
 
// NOW create a page. The renderer will start with the correct flags.
const page = await context.newPage();

A second context with --bot-noise-seed=200 produces an entirely different fingerprint while both remain reproducible across restarts.

Use Cases

Multi-Tenant Isolation

Assign a unique seed per tenant or account. Each seed produces a distinct fingerprint identity that remains stable over time.

Reproducible Testing

Use a fixed seed during development and testing to get consistent fingerprint hashes. This simplifies debugging and regression testing.

Session Persistence

Relaunch sessions with the same seed to maintain fingerprint continuity across restarts, without needing to preserve browser state.

Complete Example

import { chromium } from "playwright-core";
 
const browser = await chromium.launch({
  executablePath: process.env.BOTBROWSER_EXEC_PATH,
  headless: true,
  args: [
    `--bot-profile=${process.env.BOT_PROFILE_PATH}`,
    "--bot-noise-seed=42",
    "--proxy-server=socks5://user:pass@proxy.example.com:1080",
  ],
});
 
const page = await browser.newPage();
await page.goto("https://example.com");
 
// ... use the page as needed ...
 
await browser.close();

To verify noise seed reproducibility:

1. Launch BotBrowser with a profile and --bot-noise-seed=42, then visit a fingerprint testing site such as BrowserLeaks  or CreepJS .
2. Record the reported Canvas, WebGL, and AudioContext fingerprint values.
3. Launch a second session with the same profile and seed, and confirm the values are identical.
4. Change the seed to a different value (e.g., --bot-noise-seed=43) and confirm the fingerprint values differ.

Common Scenarios

• Capture a baseline result using the Quick Start setup.
• Change one relevant setting at a time and compare the new output.
• Keep your final launch command documented so future checks are reproducible.

Troubleshooting / FAQ

Next Steps

• CLI Flags Reference. Complete list of all available flags, including --bot-noise-seed.
• Advanced Features. Multi-layer fingerprint noise architecture.

Legal Disclaimer & Terms of Use  • Responsible Use Guidelines . BotBrowser is for authorized fingerprint protection and privacy research only.