Web Scraping using REST APIs: A clarification

I see people conflating "web scraping using REST APIs" all the time.

Why is this confusing?

Because they're usually talking about two completely different things.

When someone says "web scraping using a REST API," they either mean:

• (1) scraping a website's internal REST API directly, OR

• (2) using a third-party scraping service's REST API to do the scraping for them.

Understanding which one you need is the key to not wasting your time (like building a web scraper with c).

Let's break down both approaches.

Method 1: Scraping a Website's Internal API

This is my favorite approach (when it works).

The idea is simple: instead of parsing messy HTML, you find the JSON endpoint the website itself uses and hit it directly.

When you see a product list update without a page reload, or a dashboard refresh dynamically, that's usually a Fetch/XHR request to an internal API. Your job is to find that endpoint and call it yourself.

How to Find API Endpoints

Open your browser's DevTools:

1. Right-click -> "Inspect"
2. Go to the Network tab
3. Filter by Fetch/XHR
4. Navigate the site and watch the requests appear
5. Click on them to see the URL and JSON response

That's it.

Now you just need to call that endpoint from your code and automate the scraping task.

Python Example

Once you have the endpoint, getting the data is trivial:

import requests

api_url = "https://some-ecommerce-store.com/api/v2/products?page=1"

headers = {
    "User-Agent": "Mozilla/5.0",
    "Accept": "application/json"
}

response = requests.get(api_url, headers=headers)

if response.status_code == 200:
    data = response.json()
    print(data)

Why This Approach Rocks (And Why It Doesn't)

Pros: You get structured JSON directly, it's fast, and it's computationally cheap.

Cons: Endpoints can change without warning. They might require authentication tokens. Sometimes they're obfuscated or rate-limited aggressively.

Basically, when it works, it's the best. When it doesn't, you need a different approach.

Method 2: Using a Web Scraping API Service

Sometimes the internal API approach isn't viable. The site might use heavy JavaScript rendering, have aggressive anti-bot measures, or rotate authentication tokens constantly.

This is where web scraping API services come in handy.

These services handle the entire scraping process - proxy rotation, headless browsing, anti-bot bypass - and give you the data through a simple API call.

When This Makes Sense

• Fast Development: Send a URL, get data back. No infrastructure to maintain.
• Complexity Handled: Proxies, CAPTCHAs, and headless browsers are all managed for you.
• Scalability: Built to scrape at scale without getting blocked.

When It Doesn't

• Cost: Free tiers exist, but large-scale scraping will cost you.
• Less Control: You're dependent on the service's infrastructure and uptime.
• May be complex: In most cases (unless you're using Ai Powered Web Scrapers), you'll still need to parse the messy html yourself.

I'd recommend this approach over doing it yourself if you're bottlenecked by anti-bot measures or need to scale quickly without building infrastructure.

If you're dealing with unstructured data, this is usually the best approach as well.

Otherwise, finding the internal API is usually faster and cheaper.