How to Bypass Cloudflare with Puppeteer

Cloudflare currently protects nearly 20% of internet traffic with its robust and advanced security systems. Using a combination of anti bot measures, core browser fingerprinting, and behavior analysis, Cloudflare creates a nearly impenetrable barrier for automated scraping tools. For web scrapers and browser automation projects—whether you’re using NodeJS Puppeteer or other Puppeteer alternatives—the Cloudflare Challenge is one of the biggest hurdles. Relying solely on a simple Puppeteer script that launches headless browsers often results in performance issues, permission issues, and interruptions to your browser session, costing you both time and resources. Understanding and employing an efficient solution not only saves processing power (CPU by default) and reduces the risk of your process being halted but also helps maintain a smooth, uninterrupted scraping or browser testing framework.

In this guide, we’ll explore various methodologies—including using the puppeteer core lib, popular tools like puppeteer extra-plugin stealth, and custom scripts—before demonstrating why the Kameleo anti detect browser is the only all in one solution that creates genuine browser instances with a fresh user profile and correct browser bindings (i.e. the proper integration of browser APIs and properties that real browsers have).

How Does Cloudflare Detect Bots?

Cloudflare employs a comprehensive suite of security checks to distinguish between requests from real browsers and those from bots. These include:

• User-Agent Strings & HTTP Headers: Cloudflare verifies that the browser bindings and HTTP headers match those of popular Chromium browsers.
• JavaScript Challenges & Challenge Page URL: It sends JavaScript challenges that only an actual browser can solve.
• Rate Limiting, Event Tracking, and Mouse Movements: Cloudflare monitors human behavior by tracking mouse movements and form submissions, which are key indicators of real users.
• Browser Fingerprinting & Canvas Fingerprinting: Techniques like canvas fingerprinting and TLS/HTTP2 fingerprinting expose discrepancies between headless browsers and real browsers.
• Environmental API Checks: Cloudflare compares values such as navigator.userAgent and navigator.platform to detect inconsistencies.
• Cloudflare Worker & Cloudflare Turnstile: These systems add an extra layer of security, making sure that any automation is subject to rigorous checks.

By combining these advanced anti bot measures with a detailed behavior analysis of web requests, Cloudflare’s bot detection system ensures that even minor detectable traits in your Puppeteer script can lead to a block.

Why Puppeteer Alone Can’t Bypass Cloudflare

While Puppeteer is a powerful tool for browser automation and a popular choice for building a Puppeteer scraper or a full Puppeteer project, it falls short when it comes to bypassing Cloudflare on its own:

• Headless Browser Limitations: Headless browsers inherently lack several key browser features (like plugins and a proper browser user profile) that are expected from an actual browser.
• Detectable Fingerprinting: The core puppeteer approach in headless mode reveals detectable traits, such as differences in browser fingerprinting, CDP leaks and missing legitimate browser properties.
• Ineffectiveness in Non Headless Mode: Even when using a Puppeteer script that launches in non headless mode, advanced security checks such as Cloudflare Turnstile, CAPTCHA challenges, and bot detection systems continue to block the automation.

In short, while Puppeteer offers a high level API for Browser automation and supports Server-Side Rendering for Single-Page Applications, it does not inherently provide the additional measures needed to bypass advanced anti bot systems like Cloudflare’s. This is where anti detect browsers like Kameleo come into play, as they use advanced techniques to mask your digital fingerprint and mimic human behavior, making it easier to bypass sophisticated anti bot systems like Cloudflare’s.

What Happens When You Use Vanilla Puppeteer?

When using vanilla Puppeteer (commonly known as "Puppeteer") to access a Cloudflare protected website, the code is straightforward. However, if you rely solely on Puppeteer in its default configuration, you'll quickly find that Cloudflare's robust security measures detect the automated behavior and completely block your browser session from accessing the site.

Code example:

Explanation:

• This Puppeteer script uses the puppeteer core lib to launch a headless browser—a common approach in browser automation.
• The browser session is initiated with a browser instance and a new page, using a high level API for browser automation.
• When accessing a Cloudflare protected website, Cloudflare’s advanced security checks (including canvas fingerprinting and HTTP browser headers) immediately detect the use of headless browsers and generate a “Sorry, you have been blocked” message.

Shortcomings:

• Headless mode and the lack of a genuine browser user profile result in missing legitimate browser properties.
• This leads to detection by Cloudflare’s anti bot measures, Cloudflare Turnstile, and even environmental API checks.

How to Bypass Cloudflare with Puppeteer

In this section, we explore several techniques—including using the stealth plugin, Puppeteer Real Browser, custom DIY fortification, and finally, the Kameleo anti detect browser solution—to bypass Cloudflare’s advanced security measures.

Method I: Use Stealth Plugin

Code Example:

Explanation:

• The puppeteer extra-plugin stealth Cloudflare evasion technique modifies certain browser characteristics such as the navigator properties and canvas fingerprinting.
• This method attempts to mimic real browsers by adjusting browser bindings and simulating genuine human behavior (e.g., mouse movements, event tracking).

Pros:

• Simple integration with existing Puppeteer projects.
• Masks several detectable traits, providing a temporary bypass.

Cons:

• Does not fully overcome advanced security checks like Cloudflare Turnstile.
• Still susceptible to core browser fingerprinting and missing legitimate browser properties.

Method II: Use Puppeteer Real Browser

Code Example:

Explanation:

• This approach uses the puppeteer-real-browser library, which creates a more genuine browser environment by injecting unique fingerprints and handling CAPTCHA challenges automatically.
• The fingerprint: true and turnstile: true options enhance the ability to mimic an actual browser, ensuring the automation process is more similar to that of real users.‍

‍Pros:

• Provides a higher level of stealth by addressing advanced anti bot measures.
• Reduces the risk of detection by creating a more authentic browser session with correct browser features.

Cons:

• Requires additional configuration and may be more resource-intensive.
• Even with these enhancements, some advanced Cloudflare defenses might still eventually detect subtle anomalies.

Method III: Fortify Puppeteer Yourself

Code Example:

Explanation:

• This DIY method involves manually overriding properties and setting a custom user agent to mimic an actual browser.
• The script specifically targets issues like the navigator.webdriver flag and canvas fingerprinting, which are common detectable traits in headless browsers.
• Unfortunately, this method fails to bypass Cloudflare's anti-bot measures, as demonstrated in the screenshot and confirmed when running the example code above.

Pros:

• Highly customizable to target specific aspects of browser fingerprinting and other anti-bot measures.
• No additional external libraries are required beyond Puppeteer.

Cons:

• Requires constant maintenance as Cloudflare’s security measures evolve.
• Can lead to complex, hard-to-maintain code that might introduce performance issues and permission issues.

Method IV: Kameleo Anti Detect Browser

Code Example:

Explanation:

• The Kameleo anti detect browser uses the Kameleo Local API to launch genuine browser instances.
• By connecting to a Kameleo profile via a WebSocket URL, your Puppeteer script gains access to a true actual browser that has a fresh user fingerprint and correct browser bindings.
• This method avoids detectable traits by ensuring the session includes all the legitimate browser properties expected by Cloudflare, such as proper browser rendering, and simulates real human behavior.

Pros:

• Real Browsers & Browser Instances: Provides genuine Chromium browsers with a fresh user profile, eliminating issues common with headless mode.
• Advanced Evasion: Handles core browser fingerprinting, canvas fingerprinting, CDP leaks and other advanced security measures effectively.
• High-Level API Integration: Seamlessly connects using a browser instance via a programmatic interface, making it a powerful tool for browser automation and web scraping.
• Resource Efficiency & Maximized Success Rate: Minimizes the need for additional tools like CAPTCHA-solving services, reducing complexity and potential performance issues.

For further details and code examples, please refer to the official Kameleo documentation here.

Comparison of Methods

Legal and Ethical Considerations

While this article focuses on technical methods for bypassing Cloudflare’s anti‑bot systems, it is important to note that such actions can raise legal and ethical issues. Always ensure that your web scraping or automation activities comply with applicable laws, terms of service, and ethical guidelines. Use these techniques responsibly and only on websites where you have explicit permission to do so.

Why Kameleo Stands Out

Kameleo is the only solution that fully addresses the multi‑layered challenges of bypassing Cloudflare. It leverages a high‑level API to create real browser sessions that have all the attributes of an actual browser, including:

• Accurate Browser Bindings & Browser Rendering: Ensuring that every browser instance simulates genuine human behavior with correct browser features.
• Fresh Fingerprints: Every session gets a new user profile, mitigating issues related to core browser fingerprinting and canvas fingerprinting.
• Self-Hosted & Cost-Effective Browser Automation: Ideal for use in modern automation projects where maintaining a smooth testing environment and dynamic content rendering (e.g., Server-Side Rendering and Single-Page Applications) is critical.
• Efficient Tools & Advanced Anti-Bot Measures: Kameleo’s solution includes additional measures that automatically handle Cloudflare Turnstile, advanced security checks, and even Cloudflare Worker tasks.
• High-Level API & Programmatic Interface: The integration via a simple WebSocket URL (browser URL) ensures that your Puppeteer script remains clean and efficient, with minimal risk of triggering anti-bot systems.

Overall, Kameleo is a premium product for browser automation that saves significant resources, prevents performance issues, and avoids the pitfalls of DIY approaches, or reliance on less effective popular tools.

Ready to revolutionize your automation experience?

If you'd like to explore Kameleo, check out these pages:

Getting started with Kameleo Automation

Using Kameleo with Automation Frameworks

Start your Kameleo Journey Now!

Outsmarting Cloudflare: The Kameleo Advantage

Bypassing Cloudflare with Puppeteer is a complex challenge due to the advanced security measures—ranging from browser fingerprinting and canvas fingerprinting to behavior analysis and Cloudflare Turnstile. While various methods such as vanilla Puppeteer, stealth plugins, real browser emulation, and DIY fortification each offer partial solutions, they all have significant limitations that can lead to performance issues, permission issues, and overall inefficiency.

Kameleo anti detect browser stands out as the only truly robust solution. With its high level API, genuine browser sessions, fresh user profiles, and accurate browser bindings, it ensures that your automation process is indistinguishable from that of real users. This advanced solution not only bypasses the Cloudflare challenge and related anti bot measures but also supports modern browser testing frameworks, Server-Side Rendering, and Single-Page Applications—making it an indispensable tool for any Puppeteer project.