Beginner guide to setting up custom scraping rules in Instant Data Scraper

If you’ve ever tried to grab data from a website and ended up with a mess of half-broken tables or missing info, you’re not alone. Scraping’s one of those things that sounds simple—until you actually try to do it. Instant Data Scraper is a browser extension that promises to automate the process, but its “auto-detect” feature only works so well. If you want to scrape reliably, you’ll need to set up your own custom rules.

This guide is for anyone who’s tinkered with Instant Data Scraper but found the results lacking. Maybe it missed key fields, grabbed the wrong stuff, or choked on a slightly weird HTML layout. We’ll walk through how to create custom scraping rules that actually work, even if you’re new to the whole thing.

Why Custom Scraping Rules Matter

Let’s get this out of the way: the default “auto-detect” in Instant Data Scraper is fine for basic pages—think boring lists or simple tables. But the second a website gets a little creative with its design, auto-detect gets confused. You’ll either get messy data, or nothing at all.

Custom rules let you:

  • Target exactly what you want (no more irrelevant junk)
  • Fix broken or incomplete scrapes
  • Handle weird layouts and nested info
  • Save a ton of manual cleanup later

If you’re scraping anything important, or doing it more than once, you’ll want to learn this.

What You’ll Need

  • Google Chrome (or a Chromium-based browser)
  • Instant Data Scraper extension installed
  • A basic understanding of how web pages are structured (but you don’t need to know how to code)
  • Patience—the first few times might be a little fiddly

Step 1: Open the Target Page and Launch Instant Data Scraper

Start by finding the web page you want to scrape. Open it in your browser.

  • Click the Instant Data Scraper icon in your browser’s extension bar.
  • The extension will try to auto-detect data. Don’t worry if it looks wrong—we’re about to fix that.

Pro tip: Pages that load data dynamically (as you scroll or click) can trip up any scraper. If the data you want isn’t visible right away, scroll or interact until it’s loaded before launching the extension.

Step 2: Inspect the Data You Want

This is the part where most folks get tripped up. You need to figure out how the data you want is structured on the page. Here’s the simplest way:

  1. Right-click on the bit of data you want (for example, the product title, price, or link).
  2. Choose Inspect. This opens Chrome’s Developer Tools, showing you the HTML for that element.
  3. Look for patterns. Are similar items wrapped in the same type of HTML tag or class? Is there a table, a list, or a bunch of divs?

You don’t need to know HTML inside and out, but getting comfortable with this view helps a ton.

Quick checklist: - Are the items you want grouped together in the HTML? - Is each item in a repeating container (like <div class="item"> or <tr> for table rows)? - Can you see a unique class or tag that separates what you want from what you don’t?

Step 3: Set Up a Custom Selector

Now we get to the meat of it. Instant Data Scraper lets you define what to scrape using CSS selectors. Don’t panic—this isn’t as scary as it sounds.

What’s a CSS Selector?

Think of a CSS selector as a way to point at exactly the part of the page you care about. For example:

  • div.product points at every <div class="product">
  • table tr points at every row in a table

How to Add a Custom Selector

  1. In Instant Data Scraper, find the “Advanced” section or click on “Custom Extraction” (wording may vary slightly by version).
  2. You’ll see a field to add a CSS selector for the items you want to scrape.
  3. Enter the selector you found in the previous step.

Example:
If you’re scraping a product listing and each product is in <div class="product-card">, enter div.product-card.

Pro tip:
If you’re not sure, try several selectors and see which one highlights just the stuff you want. You can test selectors live in the browser’s console using document.querySelectorAll('your-selector').

Common Patterns

  • Lists: ul > li or .list-item
  • Tables: table tr (but skip the header row if you don’t want it)
  • Cards: .card, .item, .result

Step 4: Map the Fields You Want

It’s not enough to grab the whole chunk—you want specific details (like name, price, link, etc).

  1. In the Instant Data Scraper custom setup, there’s usually a way to add columns or fields.
  2. For each field, define a selector relative to the main item.

Example:
If your main selector is div.product-card, and the title is in an <h2> inside that div, use h2 as the field selector.

  • Name: h2
  • Price: .price
  • Link: a (and select the href attribute if needed)

Tip:
Instant Data Scraper lets you choose whether to extract text, HTML, or an attribute (like a link). For most cases, “text” is what you want.

Step 5: Preview and Test

Don’t skip this. It’s rare to get everything perfect on the first try.

  • Use the “Preview” or “Test” button (if available) to see what your rule grabs.
  • Check for missing fields, extra junk, or weird formatting.
  • Adjust your selectors until the preview looks right.

What to watch for: - Extra blank rows: Your selector is too broad. - Missing data: Your selector is too narrow or points at the wrong element. - Repeated data: You might be selecting a container inside another repeating container.

Debugging Common Problems

  • Selectors grabbing nothing: Double-check spelling and classes. Some sites use dynamic class names that change as you reload.
  • Selectors grabbing too much: Add more specificity, like .product-card h2 instead of just h2.
  • Nested data: Sometimes, data you want is inside several layers. Use a selector like .item .details .price to drill down.

Step 6: Start Scraping (and Save Your Rule!)

Once your preview looks good:

  • Hit the scrape/download button.
  • Export as CSV, XLSX, or whatever you need.

Most versions of Instant Data Scraper let you save your custom rule for that site. Do this if you’ll need to scrape it again.

Warning:
Sites change layouts often. Your custom rule might stop working without warning. If it does, repeat the steps above.

What Works, What Doesn’t, and What to Ignore

What works: - Scraping static pages with clear, repetitive layouts (lists, tables, cards) - Custom selectors for grabbing exactly what you want

What doesn’t: - Scraping sites that load data with JavaScript after the page loads—unless you can get all the data visible first - Pages with anti-bot measures (CAPTCHAs, heavy obfuscation)

What to ignore: - Don’t waste time with the “auto-detect” if it’s obviously wrong. Go straight to custom. - Don’t overcomplicate selectors. Start simple, and only add complexity if you need to.

Tips for Staying Sane

  • Iterate: You’ll rarely get it perfect on the first try. Tweaking is normal.
  • Keep selectors simple: Start broad, then narrow down.
  • Document what works: Save your selectors somewhere—especially if you’re scraping the same site regularly.
  • Respect website terms: Don’t scrape sites that explicitly forbid it, and don’t hammer servers with repeated requests.

Wrapping Up

Custom scraping rules sound intimidating, but they’re just a way to tell Instant Data Scraper exactly what you want. Start with simple selectors, preview often, and don’t be afraid to experiment. Most of all: keep it simple, and tweak as you go. The less you overthink it, the better your results will be.