Navigator Properties Protection

The navigator object is one of the most information-rich API surfaces in the browser. BotBrowser controls every property through its profile system to ensure internal consistency.

Prerequisites

Familiarity with Browser Fingerprinting Explained.
BotBrowser installed with a valid profile. See Installation.

Quick Start


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

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

Overview

The navigator object is one of the most information-rich API surfaces in the browser. BotBrowser controls every navigator property through its profile system, ensuring internal consistency across JavaScript values, HTTP headers, and Worker contexts.

Configuration

Identity and Locale


# Browser brand (ENT Tier2)
--bot-config-browser-brand=chrome
 
# User-Agent version (ENT Tier2)
--bot-config-ua-full-version=146.0.7644.60
 
# Languages (ENT Tier1)
--bot-config-languages=en-US,en,de
 
# Locale (ENT Tier1)
--bot-config-locale=en-US
 
# Timezone (ENT Tier1)
--bot-config-timezone=America/New_York

Custom User-Agent (ENT Tier3)

Build a complete, internally consistent browser identity:


--user-agent="Mozilla/5.0 (Linux; Android {platform-version}; {model}) ..."
--bot-config-platform=Android
--bot-config-platform-version=13
--bot-config-model=SM-G991B
--bot-config-architecture=arm
--bot-config-bitness=64
--bot-config-mobile=true

BotBrowser auto-generates matching Client Hints values (brands, fullVersionList with proper GREASE) and all corresponding HTTP headers. Values stay consistent across the main thread, workers, and HTTP requests.

Media Devices


# Use profile-defined synthetic devices (default)
--bot-config-media-devices=profile
 
# Use real system devices
--bot-config-media-devices=real

Network Information

Use one policy for JavaScript network information and corresponding Client Hints:


# Use all available profile values
--bot-network-info-override
--bot-network-info-override=profile
 
# Keep native Chromium values
--bot-network-info-override=false
 
# Override selected fields; omitted fields stay native
--bot-network-info-override='{"effectiveType":"3g","rtt":180,"downlink":1.8,"saveData":false}'
 
# Resolve each field from the profile, host, or an explicit value
--bot-network-info-override='{"type":"profile","effectiveType":"profile","rtt":"host","downlink":2.5,"downlinkMax":"host","saveData":"profile"}'

The bare flag, an empty value, true, and profile use every available value under the profile’s network information. false keeps native Chromium behavior.

A JSON policy accepts these fields:

Field	Custom value	Source selectors
`type`	`wifi`, `cellular`, `ethernet`, `bluetooth`, `wimax`, `other`, `none`, `unknown`	`profile`, `host`
`effectiveType`	`slow-2g`, `2g`, `3g`, `4g`	`profile`, `host`
`rtt`	Non-negative integer in the supported range	`profile`, `host`
`downlink`	Non-negative number in the supported range	`profile`, `host`
`downlinkMax`	Non-negative number in the supported range	`profile`, `host`
`saveData`	`true`, `false`	`profile`, `host`

Omitted fields remain native. Invalid JSON, unknown fields, invalid values, or a profile selector without the required profile field reject the complete policy. A custom or host policy can be used without a profile.

The CLI policy takes priority over configs.networkInfoOverride. The profile config remains a boolean setting: true selects profile values and false keeps native behavior.

The resolved policy is scoped to the active BrowserContext and remains consistent across pages, workers, navigation, and supported request headers. Set it before creating the first page in that context.

How BotBrowser Provides Protection

BotBrowser controls all navigator properties at the browser engine level. Identity, hardware, locale, network, and media device information are all defined by the profile. JavaScript values, HTTP headers, and Worker contexts return identical, internally consistent values.

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

Problem	Solution
navigator.webdriver returns true	Verify BotBrowser profile is loaded correctly. BotBrowser handles this automatically when a profile is active.
Language doesn’t match proxy location	Use `--proxy-server` (not framework proxy) for auto-detection, or set `--bot-config-languages` manually.
UA-CH headers don’t match JavaScript values	This should not happen with BotBrowser. Verify profile is loaded and no external extensions modify headers.
hardwareConcurrency shows host value	Ensure profile defines the CPU core count and is loaded correctly.
A custom network policy is rejected	Check the JSON syntax, field names, value types, and any `profile` selectors. The policy is applied atomically.

Next Steps

Screen and Window Protection. Display properties as privacy surfaces.
Performance Fingerprinting. Timing and connection data control.
Permission State Consistency. Profile-backed permission behavior across launch and per-context workflows.
Speech Synthesis Protection. Voice list consistency.
CLI Flags Reference. All identity and locale configuration flags.

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