Mistakes That Prevent You from Collecting Data from Websites

Modern anti-bot systems have learned to identify scrapers by a thousand small details: intervals that are too regular, identical headers, suspicious request frequency. If you don't adapt, data collection turns into an endless problem.

How modern websites respond to automated requests

Anti-bot systems

These are specialized software (Cloudflare, DataDome, PerimeterX) that analyze visitor behavior. If something is off — a captcha is displayed, the page doesn't load, or an empty HTML is served.

Rate limiting

Only N requests per minute can be made from a single IP. If you exceed the limit, access is restricted temporarily or permanently.

Truncated responses

The site may return not complete information but only part of it, or show an old version of the page. After collecting data from such a page, you essentially haven't gained anything useful.

Empty pages and errors

Instead of the desired content — HTTP 403 (access forbidden), 429 (too many requests), or just a white screen.

Common mistakes that hinder data collection

Sending all requests from a single IP

The scraper sends hundreds of requests per minute, all from one address? The security system will quickly figure out that it's a bot and impose restrictions.

Even if you pause between requests, one IP means one activity history. The site sees that a suspiciously high number of requests are coming from this address and will eventually block it.

Ignoring dynamic content

Modern websites load data asynchronously via JavaScript. You request a page, get an empty skeleton, and the real content is loaded later via an API. If your scraper simply downloads the HTML, it will get emptiness or unfilled blocks.

Requests that are too frequent or "dry"

The scraper sends requests without pauses, at maximum speed. The site sees abnormal activity and triggers protection.

But the problem is not just frequency. Even if you pause, but the requests look identical: the same headers, the same User-Agent, no loading of images and scripts — security systems notice that the "visitor" is not behaving like a human.

Neglecting HTTP headers and browser variety

The site looks not only at the IP but also at request headers, so simply changing it and hoping for a miracle is not the best option. User-Agent, Accept-Language, Referer, Accept-Encoding — every line can give away a bot.

A real user might use Chrome, Firefox, Safari, from different versions. But a bot always uses the same one.

Low quality or unsuitable proxy type

The IP address must be "clean" and suitable for the task. Free proxies are almost always already banned or heavily overloaded. Using the wrong type of proxy for a specific site is a guaranteed way to get blocked.

Proxies as a tool for solving problems

IP rotation

Regularly changing addresses makes traffic "less suspicious". Even if one IP gets blocked, the rest continue to work, and scraping does not stop.

Configuring proxies for tasks

A proxy needs not just to be connected but also properly configured for your scraper and target sites.

• Automatic switching on errors. If a proxy returns an error, the scraper automatically switches to the next address without stopping collection.
• Combine proxies. Use different pools for different types of sites. Use datacenter addresses for light tasks, residential ones for complex tasks.
• You can change IP after each request, after every tenth request, or at regular intervals.

Best practices for data collection

• Use proxies with automatic rotation. Manual IP changes are tedious and lead to mistakes. Pools with automatic rotation solve the problem.
• Observe timeouts and delays. Pause between requests. For this, you need proxy pools so you can maintain high collection speed without overloading a single address.
• Simulate real user behavior. Change User-Agent, load images, make random pauses. The more a request resembles a human one, the less suspicion it raises.
• Properly format request headers.
• Monitor errors and adapt. Change the proxy if it starts returning errors, update the scraper if the site changes its structure.
• For complex sites with dynamic content, use headless browsers (Puppeteer, Playwright) in conjunction with proxies. They emulate real browser behavior, load JavaScript, and handle captchas. But don't overdo it: for simple tasks, headless browsers are redundant and resource-intensive.
• Start with lightweight tools. For most sites, regular HTTP requests with correct headers and proxies are sufficient.

Belurk provides proxies that help avoid most of the problems described during scraping. The service offers support for HTTP/HTTPS and SOCKS5 protocols, as well as optimal connection speed and stability.