Web Scraping in PHP - The Complete Guide

This in-depth article will teach you how to perform web scraping using PHP, even if you're a complete beginner. By the end, you'll have a solid understanding of the best PHP libraries for scraping, how to write efficient and effective scraping code, and how to overcome common challenges. Let's dive in!

Is PHP a Good Language for Web Scraping?

PHP is a versatile language well-suited for web scraping tasks. Its extensive library support, easy-to-understand syntax, and wide availability make it an excellent choice. However, it does have some challenges compared to Python:

PHP is generally slower than Python for scraping large amounts of data

Python has a larger ecosystem of libraries specifically designed for web scraping

PHP's syntax can be more verbose than Python's

Despite these challenges, PHP remains a solid option, especially if you're already familiar with the language.

Best PHP Web Scraping Libraries

Here is a detailed comparison of the most popular PHP libraries for web scraping:

PHP Simple HTML DOM Parser
Goutte
DiDOM

Prerequisites

For this tutorial, we'll be using the PHP Simple HTML DOM Parser. To install it:

Download the latest release from the GitHub repository: https://github.com/sunra/php-simple-html-dom-parser/releases

Extract the files and include the simple_html_dom.php file in your project

We'll also be using PHP's built-in DOM extension for some tasks. This should be enabled by default, but if not, uncomment the following line in your php.ini file:

extension=php_dom.dll

Let's pick a target website

We'll be scraping the Wikipedia page for dog breeds: https://commons.wikimedia.org/wiki/List_of_dog_breeds

This page provides a nice table structure with various dog breed details that we can extract, including names, breed groups, local names, and image URLs. Scraping Wikipedia pages is also generally acceptable as the information is in the public domain.

This is the page we are talking about:

Some other good websites to practice scraping on:

IMDb movie listings: https://www.imdb.com/search/title/?groups=top_1000

Amazon product listings: https://www.amazon.com/Best-Sellers/zgbs

Google News: https://news.google.com

Write the scraping code

Here is the full scraping code we'll walk through:

// Full code

// Include DOM extension
include 'php_dom.php';

// URL to scrape
$url = '<https://commons.wikimedia.org/wiki/List_of_dog_breeds>';

// User agent header
$context = stream_context_create(array(
  'http' => array(
     'header' => "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36"
  )
));

// Get page HTML
$response = file_get_contents($url, false, $context);

// Load HTML into DOMDocument
$doc = new DOMDocument();
$doc->loadHTML($response);

// Initialize DOM XPath
$xpath = new DOMXPath($doc);

// Find table by class name
$table = $xpath->query('//table[contains(@class, "wikitable") and contains(@class, "sortable")]');

// Initialize arrays
$names = [];
$groups = [];
$localNames = [];
$photographs = [];

// Loop through rows
foreach ($table->item(0)->childNodes as $row) {

  if ($row->nodeType == 1) {

    // Get cells
    $cells = $row->childNodes;

    // Extract column data
    $name = trim($cells->item(0)->textContent);
    $group = trim($cells->item(1)->textContent);

    $localNameNode = $cells->item(2)->firstChild;
    $localName = trim($localNameNode->textContent) if ($localNameNode);

    $imgNode = $cells->item(3)->firstChild;
    $photograph = $imgNode->getAttribute('src') if ($imgNode);

    // Download and save image
    if ($photograph) {

      $image = file_get_contents($photograph, false, $context);
      $imagePath = "dog_images/{$name}.jpg";
      file_put_contents($imagePath, $image);

    }

    // Store data
    $names[] = $name;
    $groups[] = $group;
    $localNames[] = $localName;
    $photographs[] = $photograph;

  }

}

The includes

First we include the necessary PHP libraries:

include 'php_dom.php';

The php_dom.php file is included with the DOM extension and allows us to parse HTML using built-in PHP functions. Make sure this file is in the same directory as your script.

Downloading the page

To download the HTML content of the page, we use PHP's built-in file_get_contents() function:

$url = '<https://commons.wikimedia.org/wiki/List_of_dog_breeds>';
$response = file_get_contents($url, false, $context);

This sends a GET request to the specified URL and returns the response content as a string.

A couple things to note:

file_get_contents() follows redirects by default, which may not always be desirable for scraping. Set the third parameter to false to disable redirect following.

The function can timeout on slower connections. Increase the default_socket_timeout setting in php.ini if needed.

Setting user-agent

Some websites attempt to block scraper bots by inspecting the user-agent header on requests. To avoid this, we can specify our own user-agent string matching a typical browser:

$context = stream_context_create(array(
  'http' => array(
     'header' => "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36"
  )
));

We create a stream context with the user-agent header set to a Chrome browser string. This context is then passed to file_get_contents().

For more advanced scraping, you may need to rotate user agents and other headers to avoid detection. There are PHP libraries to help automate this.

Inspecting the code

Before we start parsing the HTML, it's a good idea to inspect the page source to understand its structure. In Chrome, right-click the dog breeds table and select "Inspect".

We can see the table has classes of "wikitable" and "sortable". Each row contains 4 cells with the dog breed name, group, local name, and image. We'll use this knowledge to extract the data we need.

Parsing the HTML

To parse the downloaded HTML, we load it into a DOMDocument object:

$doc = new DOMDocument();
$doc->loadHTML($response);

This converts the HTML string into a tree-like DOM structure that we can traverse and extract data from.

If your HTML contains special characters like accents, you may need to use the mb_convert_encoding() function to properly encode it before loading.

Finding the table

Looking at the Raw HTML, we notice a table tag with CSS class wikitable sortable contains the main breed data.

To locate the dog breeds table, we use XPath to query for a table with the classes "wikitable" and "sortable":

$xpath = new DOMXPath($doc);
$table = $xpath->query('//table[contains(@class, "wikitable") and contains(@class, "sortable")]');

XPath is a powerful query language that allows us to find elements based on their tag, attributes, and position in the DOM tree.

This query says: "Find a table element anywhere in the document that contains both the "wikitable" and "sortable" classes."

If the query returns multiple results, we can access them using array notation on the resulting node list (e.g. $table[0]). In this case, there's only one matching table.

Extracting all the fields

Now that we have the table node, we can loop through its rows and extract the data for each dog breed:

foreach ($table->item(0)->childNodes as $row) {

  if ($row->nodeType == 1) {

    $cells = $row->childNodes;

    $name = trim($cells->item(0)->textContent);
    $group = trim($cells->item(1)->textContent);

    $localNameNode = $cells->item(2)->firstChild;
    $localName = trim($localNameNode->textContent) if ($localNameNode);

    $imgNode = $cells->item(3)->firstChild;
    $photograph = $imgNode->getAttribute('src') if ($imgNode);

    $names[] = $name;
    $groups[] = $group;
    $localNames[] = $localName;
    $photographs[] = $photograph;

  }

}

Breaking this down step-by-step:

We loop through each child node of the table (i.e. each row element)

We skip non-element nodes like text and comments by checking the nodeType property

For each row, we get a list of its child nodes (the cell elements)

We extract the text content of the first two cells, which contain the breed name and group

For the local name cell, we first check if it has a child text node, and if so extract its content

For the image cell, we check for an element and get the value of its src attribute

Finally, we store each extracted value in a corresponding array variable

A few things to watch out for:

Not all cells will always have a value. We need to check if the nodes exist before trying to access their content to avoid errors.

The text content of nodes often has extra whitespace that needs to be trimmed.

Element attributes like src will return null if not present. Check if the return value is truthy before using it.

Downloading and saving the images

As a bonus, let's download the dog breed images and save them to our local filesystem. We'll use file_get_contents() again to download the images:

if ($photograph) {

  $image = file_get_contents($photograph, false, $context);
  $imagePath = "dog_images/{$name}.jpg";
  file_put_contents($imagePath, $image);

}

For each src URL that we extracted:

We download the image content into a variable using file_get_contents()

We construct a file path for the image using the dog breed name

We write the image content to a local file using file_put_contents()

Make sure to create a dog_images directory in your project folder before running the script.

Note that this simple approach doesn't handle duplicate breed names well, as the image files will overwrite each other. You'd need to add extra logic to generate unique filenames in that case.

The Power of XPath and CSS Selectors

When it comes to extracting data from HTML documents, XPath and CSS selectors are two of the most powerful and flexible tools at your disposal. They allow you to precisely target elements on a page based on their tag names, attributes, classes, IDs, and more.

XPath Selectors

XPath (XML Path Language) is a query language for selecting nodes in an XML or HTML document. It provides a concise syntax for navigating the document tree and filtering elements based on various criteria.

Here are some common XPath expressions and their meanings:

/html/body/div: selects a div element that is a direct child of body, which is a direct child of

//p: selects all p elements anywhere in the document

//ul[@class='menu']: selects all ul elements with a class attribute of 'menu'

//a[contains(@href, 'example.com')]: selects all a elements whose href attribute contains the text 'example.com'

//h1[text()='Welcome']: selects h1 elements with inner text equal to 'Welcome'

In PHP, you can use the built-in DOMXPath class to query an HTML document using XPath expressions:

$dom = new DOMDocument();
$dom->loadHTMLFile('<https://example.com>');

$xpath = new DOMXPath($dom);

// Select all <img> elements
$images = $xpath->query("//img");

foreach ($images as $img) {
    echo $img->getAttribute('src') . "\\n";
}

// Select <a> elements that link to <https://example.com>
$links = $xpath->query("//a[contains(@href, '<https://example.com>')]");

foreach ($links as $link) {
    echo $link->textContent . "\\n";
}

CSS Selectors

CSS selectors are patterns used to select HTML elements based on their tag, id, class, attribute, or relationship to other elements. They offer a more compact and readable syntax compared to XPath.

Some common CSS selectors include:

div: selects all div elements

.header: selects all elements with class 'header'

#main: selects the element with id 'main'

p > a: selects a elements that are direct children of p elements

img[alt]: selects img elements that have an alt attribute defined

To use CSS selectors in PHP, you can install the symfony/css-selector library:

composer require symfony/css-selector

Then use it in combination with the built-in DOMDocument class:

use Symfony\\Component\\CssSelector\\CssSelectorConverter;

$dom = new DOMDocument();
$dom->loadHTMLFile('<https://example.com>');

$converter = new CssSelectorConverter();

// Select <img> elements with a "src" attribute
$xpath = new DOMXPath($dom);
$selector = 'img[src]';
$expression = $converter->toXPath($selector);
$images = $xpath->query($expression);

foreach ($images as $img) {
    echo $img->getAttribute('src') . "\\n";
}

// Select <p> elements that are descendants of <div> elements
$selector = 'div p';
$expression = $converter->toXPath($selector);
$paragraphs = $xpath->query($expression);

foreach ($paragraphs as $p) {
    echo $p->textContent . "\\n";
}

The CssSelectorConverter class translates CSS selectors into their equivalent XPath expressions, which can then be used with DOMXPath to query the document.

Alternative libraries and tools for web scraping

In addition to the PHP libraries covered earlier, there are other tools and approaches you can use for web scraping:

Headless browsers like Puppeteer or Selenium can scrape websites that heavily rely on JavaScript

Scraping platforms like Scrapy and Apify provide higher-level APIs for building and managing web crawlers

Prebuilt scraping datasets and APIs can give you access to structured web data without needing to write your own scrapers

Here are a few specific PHP tools to consider:

Laravel Dusk

Laravel-specific headless browser testing tool built on Chromedriver

PHP cURL

PHP cURL is a low-level library for making HTTP requests. Here's an example of web scraping using PHP cURL:

<?php

// URL of the page to scrape
$url = '<https://example.com>';

// Initialize cURL
$ch = curl_init();

// Set cURL options
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');

// Execute the cURL request
$response = curl_exec($ch);

// Check if the request was successful
if ($response === false) {
    echo 'cURL Error: ' . curl_error($ch);
} else {
    // Load the HTML into a DOMDocument
    $dom = new DOMDocument();
    @$dom->loadHTML($response);

    // Create a DOMXPath object for traversing the document
    $xpath = new DOMXPath($dom);

    // Example: Extracting all the titles on the page
    $titles = $xpath->query('//h2');

    // Loop through the titles and display them
    foreach ($titles as $title) {
        echo $title->nodeValue . "\\n";
    }

    // Example: Extracting all the links on the page
    $links = $xpath->query('//a');

    // Loop through the links and display their URLs
    foreach ($links as $link) {
        echo $link->getAttribute('href') . "\\n";
    }
}

// Close the cURL handle
curl_close($ch);

In this example:

We set the URL of the page we want to scrape in the $url variable.
We initialize a new cURL session using curl_init().
We set the cURL options:
We execute the cURL request using curl_exec() and store the response in the $response variable.
We check if the request was successful. If not, we display the cURL error using curl_error().
If the request was successful, we load the HTML response into a DOMDocument object.
We create a DOMXPath object to traverse the document using XPath expressions.
We use XPath queries to extract specific elements from the page. In this example, we extract all the h2 elements (titles) and a elements (links).
We loop through the extracted elements and display their values or attributes.
Finally, we close the cURL handle using curl_close() to free up resources.

Here's an example of using multi cURL to perform simultaneous downloads:

<?php

// Array of URLs to download
$urls = [
    'https://example.com/file1.pdf',
    'https://example.com/file2.pdf',
    'https://example.com/file3.pdf',
    'https://example.com/file4.pd    'https://example.com/file5.pdf',
];

// Create a new cURL multi handle
$mh = curl_multi_init();

// Create an array to hold the individual cURL handles
$handles = [];

// Initialize individual cURL handles for each URL
foreach ($urls as $key => $url) {
    $handles[$key] = curl_init($url);
    curl_setopt($handles[$key], CURLOPT_RETURNTRANSFER, true);
    curl_setopt($handles[$key], CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');
    curl_multi_add_handle($mh, $handles[$key]);
}

// Execute the cURL requests simultaneously
$running = null;
do {
    curl_multi_exec($mh, $running);
} while ($running > 0);

// Process the downloaded files
foreach ($handles as $key => $handle) {
    // Get the downloaded content
    $content = curl_multi_getcontent($handle);

// Generate a filename for the downloaded file
    $filename = 'file_' . ($key + 1) . '.pdf';

// Save the content to a file
    file_put_contents($filename, $content);

// Remove the individual cURL handle
    curl_multi_remove_handle($mh, $handle);
    curl_close($handle);
}

// Close the cURL multi handle
curl_multi_close($mh);

echo "All files downloaded successfully!\n";

In this example:

We define an array $urls containing the URLs of the files we want to download simultaneously.
We create a new cURL multi handle using curl_multi_init(). This handle will manage the simultaneous cURL requests.
We create an empty array $handles to store the individual cURL handles for each URL.
We iterate over the $urls array and perform the following steps for each URL:
We execute the cURL requests simultaneously using curl_multi_exec() in a loop until all requests are completed.
After all requests are finished, we iterate over the $handles array to process the downloaded files:
Finally, we close the cURL multi handle using curl_multi_close() to free up resources.

here is an example of how you can rate limit in PHP cURL:

<?php

// Array of URLs to download
$urls = [
    'https://example.com/file1.pdf',
    'https://example.com/file2.pdf',
    'https://example.com/file3.pdf',
    'https://example.com/file4.pdf',
    'https://example.com/file5.pdf',
];

// Maximum number of simultaneous downloads
$maxSimultaneousDownloads = 2;

// Delay between each batch of downloads (in seconds)
$delayBetweenBatches = 1;

// Create a new cURL multi handle
$mh = curl_multi_init();

// Initialize variables for rate limiting
$currentBatch = 0;
$totalBatches = ceil(count($urls) / $maxSimultaneousDownloads);

// Process the URLs in batches
while ($currentBatch < $totalBatches) {
    // Calculate the range of URLs for the current batch
    $startIndex = $currentBatch * $maxSimultaneousDownloads;
    $endIndex = min(($currentBatch + 1) * $maxSimultaneousDownloads, count($urls));

    // Create an array to hold the individual cURL handles for the current batch
    $handles = [];

    // Initialize individual cURL handles for each URL in the current batch
    for ($i = $startIndex; $i < $endIndex; $i++) {
        $url = $urls[$i];
        $handles[$i] = curl_init($url);
        curl_setopt($handles[$i], CURLOPT_RETURNTRANSFER, true);
        curl_setopt($handles[$i], CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');
        curl_multi_add_handle($mh, $handles[$i]);
    }

    // Execute the cURL requests simultaneously for the current batch
    $running = null;
    do {
        curl_multi_exec($mh, $running);
    } while ($running > 0);

    // Process the downloaded files for the current batch
    for ($i = $startIndex; $i < $endIndex; $i++) {
        // Get the downloaded content
        $content = curl_multi_getcontent($handles[$i]);

        // Generate a filename for the downloaded file
        $filename = 'file_' . ($i + 1) . '.pdf';

        // Save the content to a file
        file_put_contents($filename, $content);

        // Remove the individual cURL handle
        curl_multi_remove_handle($mh, $handles[$i]);
        curl_close($handles[$i]);
    }

    // Increment the current batch
    $currentBatch++;

    // Delay before starting the next batch
    if ($currentBatch < $totalBatches) {
        sleep($delayBetweenBatches);
    }
}

// Close the cURL multi handle
curl_multi_close($mh);

echo "All files downloaded successfully!\n";

Guzzle

Guzzle is a popular PHP HTTP client library that makes it easy to send requests to web pages and retrieve their content. It provides a simple and expressive interface for making GET, POST, and other types of requests, handling cookies and authentication, and parsing response data.

To install Guzzle, run the following command in your project directory:

composer require guzzlehttp/guzzle

Here's a basic example of using Guzzle to scrape a webpage:

use GuzzleHttp\\Client;
use Symfony\\Component\\DomCrawler\\Crawler;

$client = new Client();
$response = $client->get('<https://example.com>');

$html = $response->getBody()->getContents();

$crawler = new Crawler($html);

$title = $crawler->filter('h1')->first()->text();
echo $title . "\\n";

$links = $crawler->filter('a')->extract(['_text', 'href']);
print_r($links);

In this example:

We create a new Guzzle Client instance.
We send a GET request to the target URL using $client->get() and store the response.
We extract the HTML content of the response using $response->getBody()->getContents().
We create a new Crawler instance from the HTML, which provides methods for traversing and extracting data from the document using CSS selectors.
We select the first h1 element and print its text content.
We select all a elements and extract their text and href attribute values into an array.

Guzzle also supports more advanced features like asynchronous requests, middleware, and request options. For example, you can set custom headers, timeout values, and proxy settings on a per-request basis:

$response = $client->get('<https://example.com>', [
    'headers' => [
        'User-Agent' => 'My Scraper/1.0',
    ],
    'timeout' => 10,
    'proxy' => '<http://user:[email protected]:8080>',
]);

Here's an example of making asynchronous requests with Guzzle:

use GuzzleHttp\\Client;
use GuzzleHttp\\Promise;
use Symfony\\Component\\DomCrawler\\Crawler;

$client = new Client();

$urls = [
    '<https://example.com/page1>',
    '<https://example.com/page2>',
    '<https://example.com/page3>',
];

$promises = [];

foreach ($urls as $url) {
    $promises[] = $client->getAsync($url);
}

$results = Promise\\settle($promises)->wait();

foreach ($results as $result) {
    if ($result['state'] === 'fulfilled') {
        $response = $result['value'];
        $html = $response->getBody()->getContents();

        $crawler = new Crawler($html);

        $title = $crawler->filter('h1')->first()->text();
        echo $title . "\\n";
    } else {
        $reason = $result['reason'];
        echo "Request failed: " . $reason->getMessage() . "\\n";
    }
}

Some websites may have rate limits or other protections against high-volume scraping. Make sure to review the site's terms of service and robots.txt file before scraping.

here is an example of how you can rate limit in guzzle using the guzzlehttp/guzzle package and the spatie/guzzle-rate-limiter-middleware package:

use GuzzleHttp\Client;
use GuzzleHttp\HandlerStack;
use GuzzleHttp\Psr7\Request;
use Spatie\GuzzleRateLimiterMiddleware\RateLimiterMiddleware;
use Spatie\GuzzleRateLimiterMiddleware\Store;

// Create a Guzzle client with rate limiting middleware
$stack = HandlerStack::create();
$store = new Store();
$middleware = new RateLimiterMiddleware($store, 10, 60); // 10 requests per 60 seconds
$stack->push($middleware);

$client = new Client(['handler' => $stack]);

// Make requests with rate limiting
for ($i = 1; $i <= 20; $i++) {
    $request = new Request('GET', 'https://api.example.com/data');
    
    try {
        $response = $client->send($request);
        echo "Request $i succeeded: " . $response->getStatusCode() . "\n";
    } catch (\Exception $e) {
        echo "Request $i failed: " . $e->getMessage() . "\n";
    }
}

When you run this script, you should see output like:

Request 1 succeeded: 200
Request 2 succeeded: 200
...
Request 10 succeeded: 200
Request 11 failed: Too Many Requests
...
Request 20 failed: Too Many Requests

Challenges of Web Scraping in the Real World

While scraping can be a powerful tool, there are some challenges to watch out for when scraping real websites at scale:

Many sites have rate limits and bot detection mechanisms to prevent excessive automated access. Scrapers need to be rate limited and distributed across IP addresses to avoid bans.

Websites frequently change their HTML structure, which can break scrapers that rely on hardcoded element selectors. Scrapers need to be monitored and updated to handle changing target pages.

Some scraping targets may include honeypot links and other traps to catch unauthorized bots. Scrapers should respect robots.txt rules and nofollow links.

Websites that heavily use JavaScript to render content can be difficult to scrape with traditional HTTP libraries. Headless browsers or specialized scraping proxies may be needed.

Large-scale scraping can consume significant computing resources. Scraping infrastructure needs to be properly provisioned with enough memory, CPU, and network capacity.

Scraped data often requires extensive cleaning and normalization before it can be used for analysis. Data pipelines should validate and sanitize incoming scraper data.

Some best practices for handling these challenges:

Use a scraping proxy service like ProxiesAPI to manage IP rotation, CAPTCHAs, and other anti-bot measures on your behalf

Implement a queueing system like RabbitMQ to rate limit your scraper requests and gracefully handle failures

Monitor and log your scraper runs to quickly identify and fix issues with target websites

Design your data models and pipelines to be resilient to unexpected changes in scraped HTML structure

Respect robots.txt and limit concurrent requests to a reasonable amount (e.g. <1 req/sec) to avoid negatively impacting websites

Include regular tests of your scrapers with mock data to proactively catch breakages before production

Simulating a Real User with User Agents and Headers

When web scraping, it's important to simulate the behavior of a real user to avoid detection and potential blocking by websites. One key aspect of this is setting appropriate user agent strings and headers in your scraping requests.

User Agent Rotation:

A user agent is a string that identifies the browser and operating system being used to make the request. Websites often use user agent information to tailor their content and detect potential bots. To simulate a real user, you can rotate user agent strings in your scraping requests. Here's an example of how to implement user agent rotation in PHP using cURL:

<?php

// Array of user agent strings
$userAgents = [
    'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36',
    'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0',
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36',
    'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36',
];

// Function to get a random user agent string
function getRandomUserAgent($userAgents) {
    $index = array_rand($userAgents);
    return $userAgents[$index];
}

// URL to scrape
$url = '<https://example.com>';

// Initialize cURL
$ch = curl_init();

// Set cURL options
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, getRandomUserAgent($userAgents));

// Execute the cURL request
$response = curl_exec($ch);

// Process the response
// ...

// Close the cURL handle
curl_close($ch);

In this example, we define an array $userAgents that contains multiple user agent strings representing different browsers and operating systems. The getRandomUserAgent() function randomly selects a user agent string from the array. Before making the cURL request, we set the CURLOPT_USERAGENT option to a randomly selected user agent string using getRandomUserAgent($userAgents). This ensures that each request uses a different user agent, simulating different users.

Headers Rotation:

In addition to user agents, you can also rotate other headers to further simulate real user behavior. Some common headers to consider include:

Accept: Specifies the acceptable content types for the response.

Accept-Language: Specifies the preferred languages for the response.

Accept-Encoding: Specifies the acceptable encodings for the response.

Referer: Indicates the URL of the page that linked to the current request.

You can create arrays of different header values and randomly select them for each request, similar to user agent rotation. Here's an example:

<?php

// Arrays of header values
$acceptHeaders = [
    'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
    'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8',
];
$acceptLanguageHeaders = [
    'en-US,en;q=0.5',
    'en-GB,en;q=0.8,en-US;q=0.6,en;q=0.4',
];
$acceptEncodingHeaders = [
    'gzip, deflate, br',
    'gzip, deflate',
];
$refererHeaders = [
    '<https://www.google.com/>',
    '<https://www.bing.com/>',
];

// Function to get a random header value from an array
function getRandomHeader($headers) {
    $index = array_rand($headers);
    return $headers[$index];
}

// Set cURL options with random headers
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'Accept: ' . getRandomHeader($acceptHeaders),
    'Accept-Language: ' . getRandomHeader($acceptLanguageHeaders),
    'Accept-Encoding: ' . getRandomHeader($acceptEncodingHeaders),
    'Referer: ' . getRandomHeader($refererHeaders),
]);

In this example, we define arrays for different header values ($acceptHeaders, $acceptLanguageHeaders, $acceptEncodingHeaders, $refererHeaders). The getRandomHeader() function randomly selects a value from the given array. Before making the cURL request, we set the CURLOPT_HTTPHEADER option to an array of headers, where each header value is randomly selected using getRandomHeader().

By rotating user agents and headers, you can make your scraping requests appear more like genuine user traffic, reducing the chances of being detected and blocked by websites. However, it's important to note that some websites may still employ advanced techniques to detect and block scraping activities, so it's crucial to be respectful and adhere to the website's terms of service and robots.txt file.

Headless Browsers for Web Scraping

Headless browsers are web browsers that run without a graphical user interface (GUI). They can be controlled programmatically and are particularly useful for web scraping because they can:

Render and interact with JavaScript-heavy websites that simple HTTP clients can't handle

Simulate user actions like clicking, typing, and scrolling to scrape interactive content

Capture full-page screenshots and generate PDFs of web pages

Some popular headless browsers used for web scraping include:

Puppeteer: a Node.js library developed by Google that provides a high-level API to control headless Chrome or Chromium

Selenium: a cross-language framework for automating web browsers, with support for multiple browser engines like Chrome, Firefox, and Safari

Playwright: a newer library from Microsoft that supports all major browser engines and offers a unified API for automating Chromium, Firefox, and WebKit

In PHP, you can use Puppeteer or Selenium through their respective PHP bindings. Here's an example of using Puppeteer with the nesk/puphpeteer library to scrape a JavaScript-rendered page:

use Nesk\\Puphpeteer\\Puppeteer;

$puppeteer = new Puppeteer;
$browser = $puppeteer->launch();
$page = $browser->newPage();

$page->goto('<https://example.com>');
$page->waitForSelector('h1');

$html = $page->content();

$browser->close();

// Parse the rendered HTML using your preferred DOM library
$dom = new DOMDocument();
$dom->loadHTML($html);

// Extract data using DOM methods as usual
$title = $dom->getElementsByTagName('h1')->item(0)->textContent;
echo $title;

And here's the same example using Selenium with the facebook/webdriver library:

use Facebook\\WebDriver\\Chrome\\ChromeOptions;
use Facebook\\WebDriver\\Remote\\DesiredCapabilities;
use Facebook\\WebDriver\\Remote\\RemoteWebDriver;
use Facebook\\WebDriver\\WebDriverBy;

$host = '<http://localhost:4444/wd/hub>'; // Selenium server URL
$capabilities = DesiredCapabilities::chrome();
$options = new ChromeOptions();
$options->addArguments(['--headless']);
$capabilities->setCapability(ChromeOptions::CAPABILITY, $options);

$driver = RemoteWebDriver::create($host, $capabilities);

$driver->get('<https://example.com>');
$driver->findElement(WebDriverBy::cssSelector('h1'));

$html = $driver->getPageSource();

$driver->quit();

// Parse the rendered HTML using your preferred DOM library
$dom = new DOMDocument();
$dom->loadHTML($html);

// Extract data using DOM methods as usual
$title = $dom->getElementsByTagName('h1')->item(0)->textContent;
echo $title;

While these examples are great for learning, scraping production-level sites can pose challenges like CAPTCHAs, IP blocks, and bot detection. Rotating proxies and automated CAPTCHA solving can help.

Proxies API offers a simple API for rendering pages with built-in proxy rotation, CAPTCHA solving, and evasion of IP blocks. You can fetch rendered pages in any language without configuring browsers or proxies yourself.

This allows scraping at scale without headaches of IP blocks. Proxies API has a free tier to get started. Check out the API and sign up for an API key to supercharge your web scraping.

With the power of Proxies API combined with Python libraries like Beautiful Soup, you can scrape data at scale without getting blocked.

Web Scraping in PHP - The Complete Guide

Is PHP a Good Language for Web Scraping?

Best PHP Web Scraping Libraries

Prerequisites

Let's pick a target website

Write the scraping code

The includes

Downloading the page

Setting user-agent

Inspecting the code

Parsing the HTML

Finding the table

Extracting all the fields

Downloading and saving the images

The Power of XPath and CSS Selectors

Alternative libraries and tools for web scraping

Laravel Dusk

PHP cURL

Guzzle

Challenges of Web Scraping in the Real World

Simulating a Real User with User Agents and Headers

User Agent Rotation:

Headers Rotation:

Headless Browsers for Web Scraping

Browse by language:

The easiest way to do Web Scraping

Web Scraping in PHP - The Complete Guide

Is PHP a Good Language for Web Scraping?

Best PHP Web Scraping Libraries

Prerequisites

Let's pick a target website

Write the scraping code

The includes

Downloading the page

Setting user-agent

Inspecting the code

Parsing the HTML

Finding the table

Extracting all the fields

Downloading and saving the images

The Power of XPath and CSS Selectors

Alternative libraries and tools for web scraping

Laravel Dusk

PHP cURL

Guzzle

Challenges of Web Scraping in the Real World

Simulating a Real User with User Agents and Headers

User Agent Rotation:

Headers Rotation:

Headless Browsers for Web Scraping

The easiest way to do Web Scraping

Don't leave just yet!