Web Crawler Vs Web Scraper: Differences and Proxy Needs

Before you write a line of code, you need to know whether you are building a crawler, a scraper or both. Pick wrong and you either hit a site far harder than the job needs, or you end up with a pile of URLs and no data.

Key takeaways

• A crawler discovers URLs by following links, while a scraper extracts specific fields such as name, price and availability from URLs you already have.
• If you already have a sitemap, feed or URL list, build only a scraper; if you don't know which pages exist, crawl first and scrape second.
• Add Playwright to the scraper, not the crawler, and only for pages that need JavaScript to show their content.
• Re-scrape known URLs often and re-crawl rarely, because prices change faster than a site's structure.
• Proxies spread requests across many IPs and give country-targeted results, but they do not replace robots.txt, crawl delays or site terms.

This guide separates the two jobs, shows how a real project uses them together, and says when proxies earn their place.

Web Crawler vs Web Scraper: What You Are Actually Deciding

A crawler discovers URLs by following links. A scraper pulls specific fields from pages you already know about.

Take a price-monitoring team that tracks a public product catalogue. They start with the crawl: the bot loads a category page, follows every product and sub-category link, and keeps going until it has a list of product URLs. That list is the crawler's whole output, a map of which pages exist.

Then comes the scrape. For each known product URL, a scraper requests the page and extracts three fields: name, price and availability. It does not wander. It goes to the address, takes what it needs and moves on.

The last step is scheduling, and this is where teams save the most effort. Prices change often, so the team re-scrapes known URLs on a frequent cycle. The catalogue's structure changes slowly, so they re-crawl only now and then to pick up new products and drop dead ones.

How the two compare, criterion by criterion

Criterion | Web crawler | Web scraper

Goal | Discover and map pages | Extract specific fields

Input | A seed URL or a few category pages | A list of known URLs

Output | A list of URLs, a site map or an index | Structured records such as name, price, stock

Breadth vs precision | Broad: covers a whole site | Precise: only the fields you named

Typical tools | Scrapy | Scrapy; requests with BeautifulSoup for static pages; Playwright for JavaScript-rendered pages

Request volume | Many requests spread across a site | Targeted requests to known pages

Failure mode | Loops, duplicate URLs, runaway depth | Broken selectors when the page layout changes

Scrapy handles both jobs in one framework, which is why many teams start there. Requests with BeautifulSoup is the lighter choice when the HTML already contains the data. Playwright drives a real browser, so it belongs on pages that only show their content after JavaScript runs. If you are weighing that last option, when scraping needs a headless browser explains the trade-off.

Which one should you build?

Your decision comes down to whether you already know the URLs.

• You have a sitemap, a feed or a URL list. Build only a scraper. Crawling adds requests you do not need.
• You do not know which pages exist. Crawl first, then scrape. This is the catalogue case above.
• You are auditing or mapping a site. Build a crawler only. Broken links, page depth and site structure are all crawl outputs.
• The pages are rendered by JavaScript. Add Playwright to the scraper, not the crawler, and only for pages that need it. A crawler can usually find links in the plain HTML, and a browser on every request is slow and costly.

One limit is worth stating plainly. Neither tool tells you whether a page is yours to collect, so the legal and ethical call stays with you.

Politeness applies to both

Crawlers fan out, so they carry most of the risk of overloading a server. Scrapers send fewer requests, but a scraper that re-checks thousands of pages on a tight loop can cause the same trouble. The request pattern differs, and the rules do not.

Start with robots.txt. The robots exclusion convention, documented at robotstxt.org, is the long-standing way a site tells automated clients which paths to leave alone, and a responsible bot reads it before the first request. Then set a crawl delay between requests, keep to the site's rate limits and read its terms. Brin and Page's original Google paper calls crawling the most fragile part of their system, because it touches hundreds of thousands of servers outside their control, and mentions almost daily emails from site owners who noticed how many pages it had fetched. Thelwall and Stuart's 2006 review of web crawling ethics argues the same from the site owner's side: weigh what your crawl costs the sites you visit, in server load and privacy, before you run it.

Stay on public pages. Do not crawl login-gated areas or collect personal data, and never treat robots.txt as optional. If you want a longer checklist, ColdProxy's post on ethical web scraping with proxies covers it.

Scraping or an API?

An API hands you the data a site owner chose to expose, in a stable format, under agreed terms. Use it when it exists and covers the fields you need. Scraping reads the public page itself.

That is why scraping is still widely used for public data. Many sites offer no API, some APIs leave out the field you care about, such as the shelf price a shopper sees, and others restrict access. A price-monitoring team usually needs what the customer sees on the page.

What is a web crawler?

A web crawler is a bot that follows links from page to page to map or index a site. Search engine bots are crawlers: they discover pages so a search index can include them.

People often say "scraping" for both jobs. In practice, many real projects crawl first to find the URLs and scrape second to pull the fields.

When Proxies Help a Crawler, a Scraper, or Both

Proxies do two honest jobs here. Neither one is magic.

First, they spread requests across many IPs, which lowers the rate-limit pressure on any single address. This matters most for crawlers, because a crawler fans out across a whole site and a single IP would carry all of that traffic. Second, country targeting gives you location-specific results, which matters most for scrapers checking local prices or regional content. If you need to see what a page shows in another market, testing a website from different locations shows how that works.

Proxies do not bypass a site's rules, and they do not solve CAPTCHAs. They help public-data work keep moving when per-IP limits would otherwise slow it down.

Here is where we would land for each reader:

• A small price-check scraper on a few pages. You may not need proxies at all. If you are polite, with delays and a low request rate, one IP can be enough.
• A broad crawl, or price monitoring across several regions. Use rotating Residential IPv4 with country targeting. ColdProxy Residential IPv4 has a 70M+ pool in 195+ countries, with rotating sessions or sticky sessions from 5 seconds to 24 hours, over HTTP, HTTPS and SOCKS5. The web scraping use case page shows how teams set it up.
• Multi-page flows on sites you own or are authorised to test. Use sticky sessions, so a flow such as a checkout test keeps one IP for the window you set; an exit failure can change the IP. For the choice between the two modes, see sticky versus rotating sessions.

The IPv6 plans are a narrower fit. Residential IPv6 (USA-only) and Datacenter IPv6 suit targets that publish IPv6 addresses or sit behind a supported CDN. You can check a target with the free IPv6 Checker before you buy, and test on the shortest paid billing period if you are still unsure. For any target that does neither, choose Residential IPv4.

Connecting a Proxy to Scrapy or Python Requests

Setup takes a few minutes. The step-by-step instructions are in the Scrapy setup docs and the Python setup docs, and you will find your real gateway, port and credentials in the client area.

This example shows the URL format with placeholder values. Swap in your own:

1import requests
2
3proxy = "http://USERNAME:PASSWORD@gw-2312.coldproxy.com:30000"
4proxies = {"http": proxy, "https": proxy}
5
6# requests: one polite call through the proxy
7r = requests.get("https://example.com/", proxies=proxies, timeout=30)
8print(r.status_code)
9
10# Scrapy: set the same value on a request
11# yield scrapy.Request(url, meta={"proxy": proxy})

Match the plan to the job. Residential IPv4 (Unmetered) is sold as a speed tier with unlimited traffic, so it suits larger, ongoing crawls; the Mbps tier is a speed limit that caps throughput, and each 1 Mbps comes with 500 concurrent connections, up to 50,000. Residential IPv4 (GB Based) is a monthly traffic pack, which suits smaller jobs you can budget by traffic. Current prices are on the ColdProxy pricing page. Residential IPv4 (Unmetered) also sells hourly periods, so you can run a short, polite crawl-then-scrape test with country targeting before you scale up.

Frequently asked questions

Is AI scraping illegal?

ColdProxy proxies are built for public-data collection, price and market monitoring, and testing sites you own or are authorised to test, whether a person or an AI tool runs the job. Before you collect from a site, read its terms and robots.txt, leave personal data and login-gated content alone, and keep your project within ColdProxy's Acceptable Use Policy.

Is ChatGPT a web crawler?

No. ChatGPT is a chat assistant, not a bot that maps sites by following links. Companies that build AI tools may run separate crawlers to collect pages, and well-behaved crawlers identify themselves and follow robots.txt rules.

Do I need proxies for a small scraper?

Often not. If you scrape a handful of pages with delays and a low request rate, a single IP can be enough. Proxies start to pay off when requests fan out across a site, or when you need results from several countries.

Which Residential IPv4 plan suits a crawl?

For a larger or ongoing crawl, Residential IPv4 (Unmetered) gives you unlimited traffic, with throughput and concurrent connections set by your Mbps tier: 500 connections for each 1 Mbps, up to 50,000. For a smaller job you want to budget by traffic, Residential IPv4 (GB Based) sells monthly traffic packs. Both offer country targeting, rotating sessions and sticky sessions from 5 seconds to 24 hours.

Can I use sticky sessions in a crawler?

Usually rotating sessions fit a crawl better, because they spread requests across many IPs. Use sticky sessions for multi-page flows on sites you own or are authorised to test, such as a checkout test: each session keeps one IP for the window you set, and an exit failure can change the IP.