Web crawling is the automated discovery of pages: a crawler starts from seed URLs, downloads each page, extracts its links, and follows them — building a map of what exists. Web scraping is the extraction step — pulling specific data out of pages. Crawling finds pages; scraping harvests them.
Every crawler is a loop around a URL frontier — the queue of pages to visit. It pops a URL, fetches the page, parses out new links, filters them (same domain? already seen? allowed by robots.txt?), pushes survivors onto the frontier, and repeats. Everything else in crawler engineering — deduplication, politeness delays per host, priority ordering, revisit scheduling — is refinement of that loop.
Search engines run the biggest crawlers (Googlebot, Bingbot), but the same machinery powers site-wide price monitoring, SEO audit tools, archive projects, and the discovery stage of most large scraping jobs. Crawlers are the audience robots.txt was invented for, and well-behaved ones honor it along with per-host rate limits.
The two get conflated because real projects usually need both, in sequence: crawl an e-commerce category to discover its 40,000 product URLs, then scrape each product page into structured fields. Discovery is a crawling problem (link graphs, sitemaps, pagination); extraction is a scraping problem (selectors, parsing, normalization).
The distinction also drives tooling: crawl frameworks (Scrapy's scheduler, sitemap parsers) optimize the frontier, while scraping tools (parsers, headless browsers, structured APIs) optimize getting clean fields out of a known page. When a target publishes a sitemap, you can often skip crawling entirely — the discovery work is already done for you.
How Crawlora handles this
Crawlora sits on the extraction side: given URLs or search queries, its endpoints return structured JSON — and platform search endpoints (search results, category listings, sitemap-backed catalogs) often replace the discovery crawl entirely, since the platform's own index becomes your frontier.
Related reading
Glossary
FAQ
Crawling discovers pages by following links from seed URLs — the output is a list of pages that exist. Scraping extracts specific data from pages — the output is structured fields. Most real projects crawl to find URLs, then scrape each one.
Google operates one — Googlebot — which continuously crawls the web to discover and refresh pages for the search index. Crawling is the discovery layer of search; indexing and ranking happen on top of what the crawler brings back.
Only if you don't already know the URLs. Sitemaps, category pagination, platform search endpoints, or an existing URL list can replace the discovery crawl — and skipping it means fewer requests, faster runs, and less load on the target site.
Browse Crawlora APIs, test a request in Playground, and move from scraping infrastructure work to production data workflows.