Cloudflare's protective measures are a tough nut to crack, and that's why so many websites rely on them. But even if it's a challenging task, also for the most experienced web scrapers, it's possible to bypass Cloudflare in Golang with the right tools.
You'll learn three of the most reliable methods to do so. But first, let's see more about what we're up against.
How Cloudflare Works
Cloudflare is a content delivery network (CDN) providing websites with internet security and performance optimization services. It reroutes users' traffic through its global network of servers and uses diverse active and passive techniques to detect bots, including:
- IP reputation: Cloudflare checks your ISP, reputation history, geolocation, and other factors against a database of IPs associated with botnets. Using residential proxies is a reliable way to avoid detection.
- Behavioral analysis: Bots have behavioral patterns, like high request rates and predictable navigation, that are notably different from how a human acts. You'll need to mimic human actions accurately.
- HTTP request headers: Cloudflare analyzes the User Agent string sent by the client to determine if it's consistent with a real web browser. That's why you should ensure your UAs are real and the headers are ordered correctly. Also, rotating UAs often is recommended to avoid suspicion.
- Canvas fingerprinting: Websites may send graphical challenges to build your unique profile and identify bots. That includes information about your browser, operating system, and graphics hardware.
- CAPTCHAs: These challenges include identifying objects in an image or solving simple math problems. While they're effortless for humans, the same can't be said regarding bots. Also, they're becoming increasingly widespread and difficult to solve, so preventing them from appearing is the best way to go.
- Request rate analysis: As Cloudflare monitors the number and frequency of requests from a particular IP, ensure your scraper doesn't behave abusively. You can also check the website's robots.txt file for web scraping to see if there are any request rate limits publicly stated.
- Machine learning: Cloudflare uses algorithms to analyze traffic patterns and detects anomalies consistent with bot activities in real time.
By using a combination of these and other techniques, Cloudflare is able to detect and mitigate bot traffic. However, there are ways to bypass its measures and access the information you want. Let's see how next.
Bypass Cloudflare in Golang
These are the three best techniques to bypass Cloudflare in Go:
ZenRows is all you need to deal with rotating IPs, CAPTCHAs, fingerprinting, and all protective measures. This web scraping tool can bypass Cloudflare's bot detection in Go with a single API call and reacts quickly to WAF updates.
Selenium and Playwright for Go
While that will be enough to avoid bot detection in many cases, you'll still get blocked with webpages with higher Cloudflare security measures.
Unfortunately, none of them support stealth plugins in Go, but you can check out our guide on how to avoid bot detection with Selenium to see how to optimize your scraper.
go-rod/rod and go-rod/stealth
go-rod/rod is a customizable driver based on DevTools Protocol for web scraping, used to automate manual actions in a browser, like filling out forms or extracting the value of input elements by class. Meanwhile, go-rod/stealth is just the extra library you need to avoid detection.
But still, they're not a sure bet to bypass Cloudflare in Golang at all times, so you need to combine it with other measures like web scraping rotating proxies for better results.
As you can see, Cloudflare has set numerous traps for your scraper, so you have to be ready for the challenge. In many cases, you can rely on tools like Selenium or go-rod with go-rod/stealth to extract data without being detected.
However, they'll inevitably fall short, as they can't hold up against Cloudflare's advanced bot detection. On the other hand, ZenRows is equipped with everything you need for the job. You can use the free 1,000 API credits to check that for yourself.