Protection against fingerprinting: how proxies help hide browser fingerprints

Blocking cookies is just the tip of the iceberg of modern tracking systems. Browser fingerprinting technologies allow for the identification of users based on a unique set of device and browser characteristics, creating a digital fingerprint that persists even after all data is cleared. For parsing, automation, and multi-accounting tasks, understanding the mechanisms of fingerprinting and methods of protection becomes critically important.

In this article, we will explore the technical aspects of digital fingerprinting, the role of proxy servers in the protection system, and practical solutions for various use cases. You will learn why proxies alone are not enough and what tools need to be combined for effective counteraction against modern anti-fraud systems.

What is browser fingerprinting and how does it work

Browser fingerprinting is a technology for identifying users based on a unique set of characteristics of their browser and device. Unlike cookies, which can be deleted, the digital fingerprint is formed from parameters that the browser automatically transmits with each request. The combination of these parameters creates a unique signature with a matching probability of less than 0.01% for most users.

The principle of operation is based on data collection through JavaScript APIs and HTTP headers. When you visit a website, scripts read dozens of parameters: screen resolution, installed fonts, time zone, language settings, WebGL version, Canvas parameters, and much more. Each parameter alone is not unique, but their combination creates a fingerprint that allows distinguishing one user from millions of others.

Statistics show impressive effectiveness: according to a study by the Electronic Frontier Foundation, 83.6% of browsers have a unique fingerprint among a sample of 286,777 tests. When adding Canvas fingerprinting, this figure rises to 94%. For commercial anti-fraud systems using advanced methods, the accuracy of identification reaches 99.2%.

The main areas of application for this technology include anti-fraud protection for banks and payment systems, preventing multi-accounting on marketplaces, combating bots and automation, as well as advertising analytics for tracking conversions. This is why parsing, traffic arbitration, and automation specialists face the need to counteract these systems.

Main methods of digital fingerprinting

Modern fingerprinting systems use a multi-layered approach, combining various techniques for maximum identification accuracy. Let's look at the key methods you will encounter when working with protected resources.

Canvas Fingerprinting

The Canvas API allows for drawing graphics in the browser, but different devices render the same image with microscopic differences due to variations in graphics drivers, operating systems, and processors. The script creates an invisible image with text and shapes, then computes its hash — resulting in a unique identifier.

// Example of Canvas fingerprinting
const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
ctx.textBaseline = 'top';
ctx.font = '14px Arial';
ctx.fillText('Browser fingerprint', 2, 2);
const hash = canvas.toDataURL().slice(-50);

The accuracy of this method is about 60-70% uniqueness, but when combined with other techniques, its effectiveness increases significantly. Protection requires either blocking the Canvas API (which breaks legitimate functionality) or spoofing the rendering results.

WebGL and GPU Fingerprinting

The WebGL API provides information about the graphics processor and drivers. The parameters WEBGL_debug_renderer_info reveal the exact GPU model, which, combined with other data, creates a persistent identifier. Additionally, rendering capabilities, supported extensions, and the performance of graphic operations are analyzed.

AudioContext Fingerprinting

A less known but effective technique uses the Web Audio API. Browsers process audio signals with microscopic differences due to codec and hardware peculiarities. The script generates an audio signal, processes it through various filters, and analyzes the result — creating a unique signature of the audio system.

Basic Browser and System Parameters

This category includes data that the browser automatically transmits or provides through standard APIs:

• User-Agent: browser version, operating system, CPU architecture
• Screen: resolution, color depth, pixel ratio (devicePixelRatio)
• Time Zone: offset from UTC and precise definition via Intl API
• Languages: list of preferred languages from navigator.languages
• Plugins and Extensions: list of installed plugins (deprecated but still used)
• Fonts: detection via Canvas or CSS font detection
• Hardware Capabilities: number of CPU cores, memory size, sensor support

Behavioral Analysis

Advanced systems analyze interaction patterns: mouse movement speed, cursor trajectories, keystroke rhythm, pauses between actions. Automated scripts demonstrate inhuman accuracy and speed, which is easily detectable. Modern anti-fraud solutions like DataDome or PerimeterX use machine learning to identify bots with up to 99.9% accuracy.

The role of proxies in protection against fingerprinting

Proxy servers solve a critically important task in the protection system against fingerprinting — they alter the network-level identification. Without proxies, even perfect browser fingerprint spoofing is useless if all requests come from a single IP address. Let's explore specific mechanisms of how proxies complement protection against digital fingerprinting.

IP Address and Geolocation Masking

The IP address is the primary identifier that cannot be hidden at the browser level. Proxies replace your real IP with an address from the desired geographical area, which is critical for tasks requiring consistency between the declared location in the fingerprint and the actual source of traffic. A mismatch in time zones between the browser and the IP geolocation is a classic sign of using a VPN or proxy.

For effective protection, it is necessary to synchronize browser parameters with proxy characteristics. If you are using residential proxies from Germany, the time zone should be set to Europe/Berlin, the browser languages should include German, and WebRTC parameters should not reveal the real IP.

Request Distribution and Preventing Account Linking

When working with multiple accounts or profiles, it is critically important that each uses a unique IP address. Anti-fraud systems actively track situations where different accounts log in from the same IP — this is a signal of multi-accounting or bots. Proxies allow isolating each profile at the network level.

Types of Proxies for Different Tasks

The choice of proxy type depends on the level of protection of the target resource and the specifics of the task:

Residential Proxies — the optimal choice for working with protected platforms. The IP addresses belong to real devices of internet service providers, making them indistinguishable from regular users. The likelihood of being blacklisted is minimal. Use for e-commerce, social networks, advertising accounts, and financial services. The downside is a higher cost and sometimes lower speed compared to data centers.

Mobile Proxies provide the highest level of trust for mobile applications and services. Mobile proxies use IPs from mobile operators, which are often shared among thousands of users — making blocking difficult. Ideal for Instagram, TikTok, mobile games, and applications with aggressive anti-fraud protection.

Data Center Proxies are suitable for tasks with lower anonymity requirements: parsing public data, SEO monitoring, availability checking. Data centers provide high speed and stability but are easily detected by anti-fraud systems based on ASN and IP ranges.

IP Rotation and Session Management

A proper IP rotation strategy is critical for long-term operation. Too frequent address changes look suspicious, while too rare increases risks if one IP is compromised. For most tasks, time-based rotation is optimal: 10-30 minutes for parsing, 1-24 hours for social media accounts, and sticky sessions (one IP for the entire session) for e-commerce and banking operations.

// Example of proxy setup with rotation in Puppeteer
const browser = await puppeteer.launch({
  args: [
    '--proxy-server=http://gate.proxycove.com:8080',
    '--disable-web-security'
  ]
});

await page.authenticate({
  username: 'user-session-12345-rotate-10m',
  password: 'your_password'
});

Why proxies alone are not enough

A common misconception among beginners is the belief that proxies solve all anonymity problems. In practice, proxies only change the IP address, while the browser fingerprint remains identical. Anti-fraud systems can easily link requests from different IPs if the fingerprint matches — this is a classic sign of proxy usage.

Real IP Leaks via WebRTC

WebRTC (Web Real-Time Communication) is used for video calls and P2P connections but has a critical vulnerability — the technology can reveal your real local and public IP address, bypassing the proxy. This occurs through STUN servers that determine the external address for establishing a direct connection.

// WebRTC can leak real IP
const pc = new RTCPeerConnection({
  iceServers: [{urls: 'stun:stun.l.google.com:19302'}]
});
pc.createDataChannel('');
pc.createOffer().then(offer => pc.setLocalDescription(offer));
pc.onicecandidate = (ice) => {
  if (ice.candidate) {
    console.log('Leaked IP:', ice.candidate.candidate);
  }
};

The solution requires either completely disabling WebRTC through browser settings, using extensions like WebRTC Leak Shield, or employing anti-detect browsers with built-in protection. Simply using a proxy without these measures leaves a critical vulnerability.

DNS Requests and Information Leaks

Even when using proxies, DNS requests may go through your real provider, revealing information about the sites visited and indirectly indicating your location. For complete isolation, it is necessary to route DNS traffic through the proxy or use DNS-over-HTTPS (DoH) with servers that match the geography of the proxy.

Mismatch of Fingerprint Parameters and IP

Anti-fraud systems check the logical consistency of data. If the proxy shows an IP from Tokyo, but the browser's time zone is set to GMT-5 (New York), the languages include only English and Spanish, and the Canvas fingerprint matches a typical Windows system from the USA — this is a clear inconsistency that is instantly detected.

Cookies and Digital Traces

Proxies do not clear cookies, localStorage, IndexedDB, and other data storage mechanisms in the browser. If you switch proxies but continue to use the same browser profile with saved cookies, the site can easily link the old and new sessions. To achieve isolation, it is necessary to use separate browser profiles or containers for each proxy.

Anti-detect browsers and fingerprint spoofing

Anti-detect browsers are specialized solutions based on Chromium or Firefox that allow creating isolated profiles with unique fingerprint parameters. Unlike regular browsers, they provide deep control over all aspects of the digital fingerprint and automatically synchronize parameters to create plausible combinations.

How Anti-detect Browsers Work

Anti-detect browsers operate at the JavaScript API level, intercepting calls to methods used for fingerprinting and returning spoofed values. For example, the call canvas.toDataURL() will return not the actual rendering result, but a pre-generated hash corresponding to the selected profile.

Key features include:

• Spoofing Canvas and WebGL: generating unique but plausible fingerprints
• User-Agent Management: automatic selection of compatible browser and OS versions
• Geolocation and Time Zones: automatic synchronization with proxy IP
• WebRTC Protection: blocking leaks or spoofing local IPs
• Fonts and Plugins: emulation of typical sets for the selected OS
• Hardware Parameters: spoofing characteristics of CPU, GPU, memory
• Profile Isolation: complete separation of cookies, localStorage, cache

Popular Anti-detect Solutions

AdsPower — an affordable solution for traffic arbitration and SMM. Offers unlimited profiles on paid plans, an API for automation, and built-in tools for working with advertising accounts. Prices start at $9/month for 10 profiles. Suitable for Facebook Ads, Google Ads, e-commerce platforms.

Multilogin — a professional solution with the highest level of protection. Uses its own browser engines Mimic (based on Chromium) and Stealthfox (based on Firefox). Prices start at €99/month. Recommended for high-risk tasks: banking operations, crypto exchanges, payment systems.

GoLogin — a balance between functionality and price. Cloud profiles, mobile application, user-friendly interface. From $24/month for 100 profiles. A good choice for beginners and medium tasks.

Dolphin Anty — free plan for 10 profiles, popular in the Russian-speaking community. Paid plans start at $89/month for 100 profiles. Active community and regular updates.

Proxy Integration with Anti-detect Browsers

Proper setup of the proxy + anti-detect combination is critical for effectiveness. Each profile should have a dedicated proxy server, and fingerprint parameters should match the geography and characteristics of the IP address.

Anti-detect browsers usually offer automatic profile generation based on the proxy's geolocation, but manual verification and adjustment of parameters increase reliability. Pay attention to the consistency of User-Agent, WebGL parameters, and operating system — inconsistencies are easily detected.

Alternative: Playwright and Puppeteer with Fingerprint Spoofing

For automation and parsing, you can use headless browsers with libraries for fingerprint spoofing. Solutions like puppeteer-extra with the puppeteer-extra-plugin-stealth or playwright-extra provide basic protection against automation detection.

const puppeteer = require('puppeteer-extra');
const StealthPlugin = require('puppeteer-extra-plugin-stealth');
const { FingerprintGenerator } = require('fingerprint-generator');
const { FingerprintInjector } = require('fingerprint-injector');

puppeteer.use(StealthPlugin());

const fingerprintGenerator = new FingerprintGenerator({
  devices: ['desktop'],
  operatingSystems: ['windows']
});

const browser = await puppeteer.launch({
  headless: 'new',
  args: ['--proxy-server=http://your-proxy:8080']
});

const page = await browser.newPage();
const fingerprint = fingerprintGenerator.getFingerprint();
const fingerprintInjector = new FingerprintInjector();

await fingerprintInjector.attachFingerprintToPuppeteer(page, fingerprint);

This approach is cheaper than anti-detect browsers but requires technical skills and is less effective against advanced anti-fraud systems. Suitable for medium complexity parsing and internal tools.

Practical solutions for different tasks

The choice of protection strategy against fingerprinting depends on the specifics of the task, the level of protection of the target resource, and the budget. Let's consider practical solutions for typical use cases.

Parsing and Data Collection

For parsing public data from sites without aggressive protection, a combination of rotating proxies and basic User-Agent spoofing is sufficient. Use libraries like requests or httpx with header and cookie configuration. For sites with JavaScript rendering, use Puppeteer/Playwright with the stealth plugin.

Recommended Configuration:

• Proxy: residential with rotation every 5-10 minutes
• User-Agent: rotation between popular versions of Chrome/Firefox
• Delays: randomized pauses of 2-5 seconds between requests
• Headless: use headless: 'new' mode for lower resource consumption
• Retry Logic: automatic retries on 429 and 503 errors

When parsing protected resources (Amazon, LinkedIn, Booking), add fingerprint spoofing using fingerprint-generator and increase intervals between requests to 10-30 seconds to simulate human behavior.

Multi-accounting in Social Networks

Social networks actively combat fake accounts and use advanced fingerprinting. Facebook, Instagram, LinkedIn link accounts based on matching fingerprints even when using different IPs. A comprehensive approach with isolation of each account is necessary.

Mandatory Requirements:

• Anti-detect browser: separate profile for each account
• Proxy: mobile proxies or residential with sticky sessions (one IP for the whole day)
• Fingerprint: unique for each profile, matching the proxy's geolocation
• Warming Up: gradually increasing activity, simulating a real user
• Cookies: retain between sessions, do not clear
• Activity: avoid simultaneous logins to multiple accounts

It is critical not to switch between profiles too quickly. If you are working with 10 accounts, distribute activity throughout the day. Use task schedulers to automate posting at different times.

Traffic Arbitration and Advertising Accounts

Google Ads and Facebook Ads use a multi-layered fraud protection system. Linking accounts can lead to mass bans. In addition to technical isolation, business logic is important: different payment methods, email addresses, phone numbers.

Technical Stack:

• Anti-detect: Multilogin or AdsPower with maximum privacy settings
• Proxy: residential with static IPs (sticky for at least 24 hours)
• Geographical Binding: proxy, time zone, languages must match the target GEO of the campaign
• Cookies Warming: visiting third-party sites before logging into the ad account
• Payment Data: virtual cards, different banks for each account

E-commerce and Sniping

Stores like Nike, Supreme, Shopify sites use bot protection (Queue-it, PerimeterX, Akamai). Successful sniping of limited releases requires speed and bypassing anti-bot systems.

Specific Requirements:

• Proxy: residential with minimal ping to the target server
• ISP Proxies: a combination of data center speed and residential trust
• Fingerprint: realistic profiles, avoid rare parameter combinations
• Cookies: pre-collection of session cookies before the release
• Automation: using specialized bots (Kodai, Cybersole) with built-in protection

Testing and QA

When testing web applications from different regions or checking geo-blocks, simulating real users from various locations is required. Anti-detect browsers are excessive for this task.

Optimal Solution:

• Proxy: residential from the required countries
• Browser: regular Chrome/Firefox with extensions for changing geolocation
• Automation: Selenium/Playwright with proxy configuration through capabilities
• CI/CD Integration: running tests through proxies in different regions in parallel

Testing and verifying the effectiveness of protection

Setting up protection against fingerprinting requires constant checking and validation. Even professional anti-detect browsers can have leaks or inconsistencies that reveal your real identity or the fact of using spoofing tools.

Tools for Checking Fingerprint

BrowserLeaks (browserleaks.com) — a comprehensive set of tests for checking various aspects of privacy. Includes checks for WebRTC leaks, Canvas fingerprint, WebGL parameters, fonts, plugins. Allows you to compare your fingerprint with a database and assess uniqueness.

CreepJS (abrahamjuliot.github.io/creepjs) — an advanced tool for deep fingerprint analysis. Detects signs of using headless browsers, virtual machines, emulators. Shows a trust score — an assessment of trust in the browser. If the score is below 70%, your configuration looks suspicious.

Pixelscan (pixelscan.net) — a service from the creators of Multilogin, specializing in checking anti-detect configurations. Provides detailed...