Web Scraping With cURL Tutorial 2025

Among the numerous tools available for web scraping these days, cURL (Client URL) stands out as a powerful, lightweight command-line tool for transferring data via various protocols, including HTTP, HTTPS, FTP, and many others. cURL operates without user interaction, making it perfect for automation and web scraping. 

In this tutorial, you’ll learn how to effectively use cURL to perform web scraping in 2025, including practical examples, common challenges, and best practices to optimize your data extraction workflows.

cURL web scraping: benefits and limitations

There are multiple reasons why developers choose the cURL command for web scraping, among which:

• Lightweightness and efficiency: cURL has minimal dependencies and consumes fewer resources compared to browser-based solutions.

• Cross-platform compatibility: Available on virtually any operating system, including Windows, macOS, Linux, and even mobile platforms.

• High customization: Offers extensive options for crafting requests with custom headers, cookies, authentication credentials, and more.

• Scriptability: Easily integrated into shell scripts, batch files, or programming languages for automated data collection.

• Proxy server support: Seamless integration with various proxy server types for enhanced anonymity and avoiding IP blocks.

• Versatile protocol support: Works with numerous protocols beyond just HTTP/HTTPS.

Meanwhile, the cURL command line has its limitations as well:

• No JavaScript execution: cURL cannot execute JavaScript, limiting its effectiveness with dynamic web pages.

• No visual rendering: Unlike browser automation tools, cURL doesn't render or interpret the visual aspects of websites.

• Manual parsing required: cURL can’t parse HTML, meaning that if this functionality is needed, you should use additional tools via the terminal for parsing. 

• Session management: Managing complex sessions can be more challenging than with specialized libraries.

Getting started with cURL for web scraping

To get started with the cURL command, follow these steps. 

1. Sending basic requests

Let's start by scraping a random quote from quotes.toscrape.com:

curl https://quotes.toscrape.com/random

Use the -L flag to follow redirects:

curl -L https://quotes.toscrape.com/random

To mimic a regular browser, set custom HTTP headers:

curl -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36" https://quotes.toscrape.com/random

2. Downloading pages

Now, save the response to a file:

curl -o random_quote.html https://quotes.toscrape.com/random

And here’s how you can download multiple web pages with a loop from macOS and Linux:

for i in {1..5}; do
  curl -o "quote_page_$i.html" "https://quotes.toscrape.com/page/$i/"
  sleep 1
done

3. Authentication methods

Most websites use form-based authentication. Here's how to handle it with cURL:

curl -L -d "username=admin&password=pass123" https://quotes.toscrape.com/login

To submit your API credentials to an endpoint, use the --user or -u flag:

curl https://realtime.oxylabs.io/v1/queries \
-u USERNAME:PASSWORD \
-H 'Content-Type: application/json' \
-d '{
        "source": "google_search",
        "query": "adidas",
        "parse": true
    }'

4. Using proxies with cURL

Using a proxy with cURL allows you to hide your IP address and avoid blocks:

# Basic proxy usage
curl -x http://proxy-server:port https://ip.oxylabs.io/

Here’s a code sample with authentication:

curl -x http://username:password@proxy-server:port https://ip.oxylabs.io/

And here’s how you can use a residential proxy:

curl -x http://customer-username:password@pr.oxylabs.io:7777 https://ip.oxylabs.io/

Alternatively, you can pass your credentials like so:

curl -x http://pr.oxylabs.io:7777 -U customer-username:password https://ip.oxylabs.io/

5. Handling dynamic content

While cURL cannot execute JavaScript, you can directly access the API endpoints that dynamic websites use. These endpoints can be found by inspecting the Network tab for Fetch/XHR requests via your browser’s Developer Tools:

curl "https://www.scrapethissite.com/pages/ajax-javascript/?ajax=true&year=2015"

This returns JSON data, which is often easy to parse.

6. Integration with Python

You can integrate cURL with Python using the subprocess module:

import subprocess
from bs4 import BeautifulSoup

def fetch_with_curl(url):
    cmd = ['curl', '-s', url]
    response = subprocess.run(cmd, capture_output=True, text=True)
    return response.stdout

# Fetch a random quote
html = fetch_with_curl('https://quotes.toscrape.com/random')

# Parse with BeautifulSoup
soup = BeautifulSoup(html, 'html.parser')
quote = soup.find('span', class_='text').text
author = soup.find('small', class_='author').text

print(f"Quote: {quote}")
print(f"Author: {author}")

For more information on this topic, visit this “How to Use cURL With Python” article.

Common issues and best practices for web scraping with cURL

Now that we have gone over the key steps of web scraping with cURL, let’s review the most common issues and best practices to resolve them. 

Rate limiting and IP blocks

Issue: Many websites implement rate limiting to prevent server overload from automated requests. If you make too many cURL requests in a short period, your IP address may be temporarily or permanently blocked.

Best practice: Respect website resources by adding delays between requests. Consider varying your request timing to mimic human browsing patterns rather than using fixed intervals. For larger websites, calculate reasonable rates based on the site's size and your needs. Implement a system to rotate between multiple proxies and user agent strings to distribute your requests across different perceived sources.

CAPTCHA challenges

Issue: Websites increasingly deploy CAPTCHA to distinguish between human users and automated scrapers. Encountering CAPTCHAs during scraping can halt your data collection process.

Best practice: Configure your requests with common browser headers, including user-agent strings, accepted content types, and language preferences. Keep these headers up-to-date with current browser versions and occasionally rotate between different common configurations. Implement session management to maintain cookies properly, which helps establish a more legitimate browsing profile.

Website structure changes

Issue: Websites frequently change their HTML structure or data formats without notice. Since cURL only handles content retrieval and not parsing, you'll need to maintain separate parsing logic that may need updates when site structures change.

Best practice: Design your separate parsing tools (whether command-line utilities or programming libraries) to be robust and adaptable. When using cURL in pipelines with tools like grep, sed, or awk, focus on stable page elements that are less likely to change. For more complex scraping, combine cURL with flexible parsing libraries like BeautifulSoup in Python, and implement regular monitoring to detect when site changes break your extraction logic.

Error handling

Issue: Scrapers frequently encounter temporary issues, including network errors, server timeouts, or unexpected response formats. Without proper error handling, these issues can cause your entire scraping operation to fail.

Best practice: Develop a comprehensive error-handling strategy for your cURL request that includes detecting various HTTP status codes, implementing exponential backoff for retries, and logging detailed information about failures. This robust approach ensures your scraper can recover from temporary issues and continue operation without manual intervention.

Dynamic content loading

Issue: Many modern websites load content dynamically through JavaScript, making it invisible to cURL's initial request.

Best practice: Identify the underlying API calls that provide the dynamic data and request those endpoints directly. Inspect network traffic in a browser's developer tools to discover these endpoints and their required parameters. This approach is often more efficient than attempting to scrape the rendered HTML, as it provides structured data in formats like JSON that are easier to parse when you need to perform web scraping on target URL content.

cURL vs. other scraping tools

Before choosing cURL for your web scraping tasks, it's helpful to understand how it compares to other popular scraping tools. Each tool has distinct strengths and limitations that make it suitable for different scenarios. The following table highlights key differences between cURL and alternative scraping solutions: