A request header is a piece of metadata a client sends to a server along with an HTTP request. Headers describe details about the request, such as the browser type, accepted content formats, and authentication tokens.
Every HTTP request includes a set of headers before the actual request body, formatted as key-value pairs like User-Agent: Mozilla/5.0. The server reads these headers to decide how to respond, such as which content format to return or whether the request looks legitimate. Scrapers customize request headers to mimic a real browser, since default headers from scripting libraries often reveal automated traffic. Common headers scrapers adjust include User-Agent, Accept-Language, and Referer.
Handle it deliberately in production scrapers -- most breakage traces back to skipping this step.
USER-country-de-session-task01Add this string to your scraper's proxy credentials and every request in the job shares one exit IP, which keeps request header-related behavior consistent across the run. Change "task01" per worker to isolate parallel scrapes.
Isolate the logic for this step so every scraper in the project shares one tested implementation.
Sites change layouts and behavior over time -- recheck this part of the scraper on a schedule, not just at launch.
This works best over residential or ISP IPs, so the target sees ordinary browsing rather than clustered datacenter traffic.
Capture what actually failed so a broken selector or a new status code surfaces instead of getting masked by automatic retries.
A scraper sets a request header that matches the User-Agent string of a real Chrome browser instead of using the default value from its scripting library.
Request headers are one of the first things anti-bot systems check, so poorly set or missing headers are an easy way to get flagged as a bot. Matching realistic headers to the pattern of a real browser is a basic but important step in avoiding detection.
The User-Agent header is often the most scrutinized, since it identifies the browser and operating system, but a full set of realistic headers, like Accept-Language and Referer, matters just as much for avoiding detection.
Yes, but the default headers from many libraries can look different from the headers of a real browser, which is why scrapers often override them manually with realistic values.
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