Working with checkers and parsers: where to use a proxy

Roman

Oct 22, 2025

Proxy

In the world of automated data collection and analysis, tools such as **checkers** (programs for checking the status of something) and **parsers** (programs for extracting information from web pages) are the main workhorses. They allow you to complete tasks in minutes that would take a person weeks to do: check the validity of thousands of accounts, collect prices from hundreds of competitors, or analyze search results across dozens of regions.

However, anyone who has run such tools “head-on” from their home or server IP address has inevitably encountered the same problem: after a few dozen or hundreds of requests, the work stops. The target site either starts returning errors, displays CAPTCHAs, or completely blocks your IP.

This article is a technical guide explaining why, for professional work with checkers and parsers, **proxies are not an option, but the fundamental basis of the entire operation.** We will analyze the protection mechanisms you encounter and what type of proxy is needed for each specific task.

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#### **Part 1. The inevitable wall: Why direct requests are doomed to fail**

When you launch a parser or checker from your IP, you are essentially firing a machine gun at a target while standing under a bright spotlight. Modern web services and their protection systems (WAF, anti-fraud systems) instantly detect such abnormal activity based on several key indicators.

1. **IP blocking and rate limiting:** This is the first line of defense. As soon as the number of requests from a single IP address exceeds a certain threshold (rate limit), the system automatically blocks that IP. For a parser that can send hundreds of requests per minute, such blocking is only a matter of time.
2. **Geo-restrictions:** Many websites display different content for different countries. If you try to parse prices for goods in the US while in Europe, you will most likely see prices for the European market or a message saying that the information is unavailable.
3. **Cloaking:** Advanced systems can determine that a request is coming from a bot (for example, by the IP address of the data center) and feed it deliberately false or outdated information, while regular users see the current data.
4. **CAPTCHA:** At the slightest suspicion of automation, the system displays a CAPTCHA. For an automated tool, this is equivalent to a complete shutdown.

##### **1.1. Not just IP: The problem of digital fingerprinting**

IP blocking is just the tip of the iceberg. Modern anti-fraud systems analyze not only *where* the request came from, but also *who* sent it. They collect and analyze the **digital fingerprint** of your connection:

* **User-Agent** (your browser and OS).
* **Browser headers** (HTTP headers).
* **WebRTC and Canvas parameters**, which can reveal the real characteristics of your system.

If thousands of requests come from different IPs but with an absolutely identical digital fingerprint, the protection system easily concludes: “This is the same bot working through a proxy pool.” Therefore, professional work involves not only changing the IP, but also **randomizing or unique digital fingerprinting** for each stream. Proxies solve the first and most important part of this task by hiding your IP.

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#### **Part 2. Areas of application: Where proxies are indispensable**

Let's look at specific types of tools whose performance is 100% dependent on the quality and quantity of proxies.

##### **2.1. SEO parsers (A-Parser, Screaming Frog, Netpeak Spider)**

* **Task:** Collecting search engine results page (SERP) positions for thousands of keywords, auditing meta tags, scanning the structure of a competitor's website.
* **Why you need a proxy:** Search giants such as Google and Yandex have some of the most advanced anti-bot systems. Massive requests from a single IP address result in instant CAPTCHA prompts and temporary blocks. To obtain relevant data from different regions (for example, to find out a site's position in search results for a New York resident), you need proxies with appropriate geotargeting.

##### **2.2. Marketplace and e-commerce parsers (Amazon, Ozon, Avito)**

* **Task:** Monitoring prices, stock availability, collecting reviews, tracking new items.
* **Why proxies are needed:** Marketplaces are highly secure fortresses. They actively combat any parsing to protect their commercial data. Successful industrial-scale data collection requires thousands of **rotating residential proxies** so that each request looks like a visit from a new, unique buyer.

##### **2.3. Account checkers (social networks, gaming platforms, forums)**

* **Task:** Checking a large list of accounts (login:password) for validity (does the account exist, is it banned).
* **Why you need a proxy:** Attempting to check even 10-20 accounts from a single IP address is a sure way to raise suspicion with the security system. The platform sees this as an attempt at brute force (password guessing). As a result, not only will your IP be blocked, but the entire network of accounts being checked may be marked as compromised. **For this task, mobile or high-quality residential proxies are required**, one for each account or with frequent rotation.

##### **2.4. Validity checkers (promo codes, email addresses)**

* **Task:** Checking a large list of data, for example, the existence of email addresses (using services such as **ZeroBounce, Snov.io, or NeverBounce**) or the functionality of a list of promo codes by sending requests to the server.
* **Why you need a proxy:** As in any other case of mass requests of the same type, the server will quickly detect the anomaly and block the IP. Proxy rotation allows you to distribute the load and avoid blocking.

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#### **Part 3. Choosing the right tool: Which proxy for what?**

* **Data center proxies:** The fastest and cheapest. **Suitable** for working with poorly protected websites or for tasks where it is not a problem to lose some proxies due to blocking. **Not suitable** for search engines and large marketplaces.
* **Resident proxies:** The “gold standard” for parsing. IP addresses of real home users inspire maximum trust. **Ideal** for collecting data from marketplaces, SEO analytics, and any large-scale tasks. The rotation option (changing the IP with each request) is key.
* **Mobile proxies:** The highest level of trust. **Indispensable** for working with social networks, especially for account checkers. Traffic from a mobile IP is virtually indistinguishable from the actions of a real smartphone user.

**The key is choosing the right rotation mode:**

* **Static IP:** This is a permanent IP address (residential or mobile) that is assigned only to you for a long period of time. This is **critically important** for working with accounts (checkers, management, posting). Using one permanent and “clean” IP for each account allows you to build trust history and avoid being blocked for suspicious logins from different addresses.
* **High rotation (IP change with each request):** Ideal for parsing search results or collecting data from thousands of pages where you don't need to maintain a session. Each request comes from a new IP, making tracking impossible.
* **Sticky sessions (IP retention for a certain period of time):** Necessary when you need to perform several consecutive actions on behalf of a single user. For example, going through several pages of pagination in a catalog or adding an item to a shopping cart.

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#### **Part 4. Common mistakes and how to avoid them**

1. **Mistake: Using data center proxies for Google/Amazon.**
   * **Result:** Instant ban. These platforms block data center IPs by default.
   * **Solution:** Only residential or mobile proxies.
2. **Mistake: Using one proxy for multiple accounts.**
   * **Result:** Blocking of the entire network of accounts if one is compromised.
   * **Solution:** Follow the “one account, one proxy” principle (or at least a small group of accounts per proxy).
3. **Mistake: Not taking geo-targeting into account.**
   * **Result:** Receiving irrelevant data (e.g., prices for another country).
   * **Solution:** Always choose a proxy from the region whose data you want to obtain.

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### **Conclusion: Proxies as a foundation**

In the context of working with checkers and parsers, proxies are no longer just a tool for anonymity. They become a fundamental, supporting element of the entire technological chain. Without a properly selected and configured pool of proxy servers, even the most sophisticated parser or checker becomes a useless script that will be blocked within the first few minutes of operation.

The efficiency, completeness, and very possibility of data collection directly depend on the quality of your proxy infrastructure.

👉 **Looking for a reliable foundation for your tasks?** For large-scale parsing, SEO analysis, and working with the most secure platforms, such as social networks, [check out the proxy catalog from CyberYozh App](https://app.cyberyozh.com/catalog/).

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