```yaml
product: AlterLab
title: "JSON — Web Scraping Glossary | AlterLab"
comparison_context: "AlterLab is an alternative to Firecrawl, ScrapingBee, and Bright Data."
source_url: https://alterlab.io/glossary/json
```

format

# JSON

JavaScript Object Notation — the universal text format for structured data exchange between APIs and web services.

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format that represents structured data as key-value pairs (objects) and ordered sequences (arrays) using JavaScript syntax. It is the dominant format for web API responses, configuration files, and data exchange between services.

In web scraping, JSON is significant in two ways. First, many modern sites make their data available via internal JSON APIs — fetching products, prices, or search results — rather than (or in addition to) embedding it in HTML. Intercepting these XHR/fetch requests directly provides cleaner, more structured data than parsing HTML. Browser DevTools' Network tab or Playwright's request interception can capture these API calls.

Second, JSON is the standard output format for structured data extraction. AlterLab's API returns extracted data as JSON objects matching the schema provided in the request, eliminating the need for HTML parsing on the caller side. Schema.org structured data embedded in pages (`<script type="application/ld+json">`) is also JSON and can provide structured product, article, or event data without scraping the rendered HTML.

### What is JSON?

JavaScript Object Notation — the universal text format for structured data exchange between APIs and web services.

### How does AlterLab handle JSON?

Second, JSON is the standard output format for structured data extraction. AlterLab's API returns extracted data as JSON objects matching the schema provided in the request, eliminating the need for HTML parsing on the caller side. Schema.org structured data embedded in pages (`<script type="application/ld+json">`) is also JSON and can provide structured product, article, or event data without scraping the rendered HTML.

## Examples

```
// JSON response from AlterLab structured extraction
{
  "url": "https://example.com/product/123",
  "status": 200,
  "data": {
    "name": "Wireless Headphones Pro",
    "price": 149.99,
    "currency": "USD",
    "in_stock": true,
    "rating": 4.7
  }
}
```

## Related Terms

[REST APIA web service that exposes data and actions through standard HTTP methods and resource-oriented URLs, returning structured JSON responses.](https://alterlab.io/glossary/rest-api)[Structured Data ExtractionConverting free-form HTML into typed JSON records using explicit schemas, producing clean structured output instead of raw markup.](https://alterlab.io/glossary/structured-data-extraction)[Data ExtractionThe process of identifying and pulling specific fields from raw web content, converting unstructured HTML into typed JSON records.](https://alterlab.io/glossary/data-extraction)[Web ScrapingAutomated extraction of data from websites using software tools that parse HTML and collect structured information at scale.](https://alterlab.io/glossary/web-scraping)

## Extract JSON data from any website

AlterLab returns clean, structured data from any public URL — no scraper infrastructure needed. Start free, no credit card required.

[View API docs](https://alterlab.io/docs/api/rest)

[Back to Glossary](https://alterlab.io/glossary)