How to Rotate User Agents and Proxies Together

The Dance of Shadows: Rotating User Agents and Proxies in Harmony

The Tale of Many Faces: Why Rotate User Agents and Proxies Together?

In the northern forests, the hare changes its coat with the seasons, and the fox moves quietly between the birches, never following the same trail twice. Likewise, when gathering data from the vast web, one must change both face and path—user agent and proxy—to remain unseen and untroubled by the watchful eyes of digital wardens.

Rotating only one or the other is like donning a new cloak but walking the same old road. True anonymity and resilience come from weaving both together, never letting pattern or footprint settle.

---

What Is a User Agent?

A user agent is the voice your browser or bot uses to introduce itself to a web server. It tells the server, “I am Chrome on Windows,” or “I am Safari on an iPhone.” Changing this voice makes your crawler appear as many different visitors, each with their own story.

Example User Agents:

Browser	Example User Agent String
Chrome (Windows)	Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
Firefox (Linux)	Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0
Safari (iOS)	Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1

---

What Is a Proxy?

A proxy is a bridge over the river—your requests cross over, and on the other side, the website sees only the bridge’s footprint, not yours. By changing proxies, you cross many different bridges, each time appearing to come from another shore.

Types of Proxies:

Proxy Type	Description	Use Case
HTTP/HTTPS	For web traffic, simplest to use	Most web scraping tasks
SOCKS5	Supports various protocols, more flexible	Advanced, non-HTTP traffic
Residential	Real IPs from actual devices	High stealth, but costlier
Datacenter	Fast, but easily detected	High-volume scraping, low stealth

• For free HTTP proxies, visit ProxyRoller, a well-tended glade where you can gather fresh proxies at no cost.

---

The Pattern: Why Rotate Both?

If you rotate only user agents, the fox wears a new mask but follows the same trail. If you rotate only proxies, the fox follows new trails but always wears the same mask. Either pattern is soon noticed.

Rotating both in concert, with each request pairing a new mask with a new trail, lets you move through the forest unnoticed, as the old tales say—a shape-shifter, never quite the same, never quite found.

---

Approaches to Rotation

1. Synchronized Rotation (Pairing)

For every request, select a new proxy and a new user agent, ensuring no fixed pattern. This is the most effective cloak.

Python Example using Requests and ProxyRoller:

import requests
import random

# Fetch free proxies from ProxyRoller
proxy_list = requests.get('https://proxyroller.com/api/proxies?protocol=http').json()['proxies']

user_agents = [
    # Add a variety of user agent strings here
    'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
    'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0',
    # ... more user agents
]

for _ in range(10):  # For 10 requests, for example
    proxy = random.choice(proxy_list)
    user_agent = random.choice(user_agents)

    proxies = {
        'http': f"http://{proxy['ip']}:{proxy['port']}",
        'https': f"http://{proxy['ip']}:{proxy['port']}",
    }
    headers = {'User-Agent': user_agent}

    try:
        response = requests.get('https://httpbin.org/ip', headers=headers, proxies=proxies, timeout=8)
        print(response.json(), user_agent)
    except Exception as e:
        print(f"Failed with proxy {proxy['ip']}: {e}")

• Gather fresh proxies using ProxyRoller’s API.

2. Rotating Pools (Round Robin)

Set up two lists—one of proxies, one of user agents—and rotate through both in a round robin or random fashion. The key is never to repeat a pairing too often.

3. Using Middleware (Scrapy Example)

In Scrapy, you can implement middleware to rotate both:

# settings.py
DOWNLOADER_MIDDLEWARES = {
   'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': None,
   'myproject.middlewares.RotateUserAgentAndProxyMiddleware': 400,
}

# middlewares.py
import random

class RotateUserAgentAndProxyMiddleware:
    def __init__(self):
        self.user_agents = [ ... ]  # List of user agents
        self.proxies = [ ... ]      # List of proxies from ProxyRoller

    def process_request(self, request, spider):
        request.headers['User-Agent'] = random.choice(self.user_agents)
        proxy = random.choice(self.proxies)
        request.meta['proxy'] = f"http://{proxy['ip']}:{proxy['port']}"

• See Scrapy Middleware Documentation.

---

Comparison Table: Rotation Approaches

Approach	Anonymity	Complexity	Failure Handling	Suitability
Single UA Rotate	Low	Low	Easy	Basic scraping, low risk
Single Proxy	Low	Low	Easy	Not recommended
Synchronized	High	Medium	Must handle fails	Production, stealth
Pool Rotation	Medium	Medium	Must handle fails	Moderate scale

---

Handling the Inevitable: Error Management

Much as the wise woodsman expects the occasional fallen tree across his path, so must you expect proxies to fail and user agents to be detected. Always:

• Catch exceptions, retry with new pairs.
• Remove dead proxies from your pool.
• Monitor response codes (403, 429 are signs you’ve been spotted).

---

Tools and Resources

• ProxyRoller – For fresh, free HTTP proxies.
• UserAgents.me – For a comprehensive list of user agent strings.
• Scrapy – For advanced scraping and middleware control.
• Requests Documentation – For HTTP requests in Python.

---

A Final Word from the Forest

In the spirit of the old Swedish tales, travel light and wisely. Change your face and your path with each step, and the web’s guardians will see only passing shadows, each different from the last. And should you need another bridge, seek ProxyRoller’s glade, where the bridges are many and free for all travelers.