Scrapers

Scrapers are software tools designed to retrieve and structure information from other digital sources, most commonly the web. They automate the collection of data that is publicly accessible by navigating pages, extracting content, and saving results in structured formats such as CSV or JSON.

Web scrapers and data scrapers represent common variants. Web scrapers focus on HTML content and page structure, while data scrapers may target APIs, PDFs, or other document types. They are used for price monitoring, competitive intelligence, content aggregation, market research, and academic data collection.

Operation typically involves fetching pages over HTTP, parsing the retrieved content, and extracting elements using CSS selectors, XPath, or pattern matching. Many scrapers handle pagination, follow links to additional pages, and store data locally or in a database. More advanced systems render JavaScript, simulate user interactions, manage login credentials, and use proxy networks to avoid rate limits or blocks. Responsible implementations include politeness policies such as delays between requests and adherence to robots.txt guidelines.

Ethical and legal considerations are important. Websites may restrict scraping in their terms of service, and automated access can raise copyright, privacy, or data-protection concerns. Compliance often involves using official APIs or licensed data sources, respecting rate limits, and avoiding the extraction of sensitive information. When used responsibly, scraping can support data analysis and transparency, but it can also cause disruption or legal risk if misused.