# renderizado de JavaScript

Si la página que deseas extraer requiere cargar JavaScript para cargar dinámicamente todos los datos necesarios en el DOM, en lugar de configurar y usar por tu cuenta un Headless Browser, puedes incluir el `"X-Oxylabs-Render: html"` encabezado en tus solicitudes. Todas las solicitudes con este encabezado incluido se renderizarán por completo, y todos los datos se almacenarán en un archivo HTML o en una captura de pantalla PNG (según el parámetro pasado).

{% hint style="info" %}
La renderización de JavaScript tarda más en extraer la página. Al usar renderización de JavaScript, establece el valor del tiempo de espera del lado cliente en 180 segundos.
{% endhint %}

{% hint style="warning" %}
Para garantizar el menor consumo de tráfico, nuestro sistema no carga activos innecesarios durante el renderizado de la página.
{% endhint %}

Este parámetro tiene dos valores disponibles: 

* `html` (HTML de una página renderizada)
* `png` (bytes sin procesar que se pueden guardar como PNG)

#### Ejemplos de código

{% tabs %}
{% tab title="cURL" %}

```shell
curl -k -v -x https://unblock.oxylabs.io:60000 \
-U 'USERNAME:PASSWORD' \
'https://ip.oxylabs.io/location' \
-H 'X-Oxylabs-Render: html'
```

{% endtab %}

{% tab title="Python" %}

```python
import requests

# Usa aquí tus credenciales de Web Unblocker.
USERNAME, PASSWORD = 'YOUR_USERNAME', 'YOUR_PASSWORD'

# Define el diccionario de proxies.
proxies = {
  'http': f'http://{USERNAME}:{PASSWORD}@unblock.oxylabs.io:60000',
  'https': f'https://{USERNAME}:{PASSWORD}@unblock.oxylabs.io:60000',
}

headers = {
    'X-Oxylabs-Render': 'html'
}

response = requests.get(
    'https://ip.oxylabs.io/location',
    verify=False,  # Es necesario ignorar el certificado
    proxies=proxies,
    headers=headers,
)

# Imprime la página de resultados en stdout
print(response.text)

# Guarda el HTML devuelto en el archivo result.html
with open('result.html', 'w') as f:
    f.write(response.text)
```

{% endtab %}

{% tab title="Node.js" %}

```javascript
import fetch from 'node-fetch';
import { HttpsProxyAgent } from 'https-proxy-agent';

const username = 'YOUR_USERNAME';
const password = 'YOUR_PASSWORD';

const agent = new HttpsProxyAgent(
  `https://${username}:${password}@unblock.oxylabs.io:60000`
);

// Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = 0;

const headers = {
   'X-Oxylabs-Render': 'html',
}

const response = await fetch('https://ip.oxylabs.io/location', {
  method: 'get',
  headers: headers,
  agent: agent,
});

console.log(await response.text());
```

{% endtab %}

{% tab title="PHP" %}

```php
<?php
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, 'https://ip.oxylabs.io/location');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_PROXY, 'https://unblock.oxylabs.io:60000');
curl_setopt($ch, CURLOPT_PROXYUSERPWD, 'YOUR_USERNAME' . ':' . 'YOUR_PASSWORD');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

curl_setopt_array($ch, array(
    CURLOPT_HTTPHEADER  => array(
        'X-Oxylabs-Render: html'
    )
));

$result = curl_exec($ch);
echo $result;

if (curl_errno($ch)) {
    echo 'Error:' . curl_error($ch);
}
curl_close($ch);
```

{% endtab %}

{% tab title="Golang" %}

```go
package main

import (
	"crypto/tls"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
)

func main() {
	const Username = "YOUR_USERNAME"
	const Password = "YOUR_PASSWORD"

	proxyUrl, _ := url.Parse(
		fmt.Sprintf(
			"https://%s:%s@unblock.oxylabs.io:60000",
			Username,
			Password,
		),
	)
	customTransport := &http.Transport{Proxy: http.ProxyURL(proxyUrl)}

	// Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
	customTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}

	client := &http.Client{Transport: customTransport}
	request, _ := http.NewRequest("GET",
		"https://ip.oxylabs.io/location",
		nil,
	)
	
	// Add custom cookies
        request.Header.Add("X-Oxylabs-Render", "html")
        
	request.SetBasicAuth(Username, Password)
	response, _ := client.Do(request)

	responseText, _ := ioutil.ReadAll(response.Body)
	fmt.Println(string(responseText))
}

```

{% endtab %}

{% tab title="C#" %}

```csharp
using System;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

namespace OxyApi
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var webProxy = new WebProxy
            {
                Address = new Uri("https://unblock.oxylabs.io:60000"),
                BypassProxyOnLocal = false,
                UseDefaultCredentials = false,

                Credentials = new NetworkCredential(
                userName: "YOUR_USERNAME",
                password: "YOUR_PASSWORD"
                )
            };

            var httpClientHandler = new HttpClientHandler
            {
                Proxy = webProxy,
            };

            // Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
            httpClientHandler.ClientCertificateOptions = ClientCertificateOption.Manual;
            httpClientHandler.ServerCertificateCustomValidationCallback =
                (httpRequestMessage, cert, cetChain, policyErrors) =>
                {
                    return true;
                };


            var client = new HttpClient(handler: httpClientHandler, disposeHandler: true);
            
            // Add custom cookies
            client.DefaultRequestHeaders.Add("X-Oxylabs-Render", "html");
            
            Uri baseUri = new Uri("https://ip.oxylabs.io/location");
            client.BaseAddress = baseUri;

            var requestMessage = new HttpRequestMessage(HttpMethod.Get, "");

            var response = await client.SendAsync(requestMessage);
            var contents = await response.Content.ReadAsStringAsync();

            Console.WriteLine(contents);
        }
    }
}
```

{% endtab %}

{% tab title="Java" %}

```java
package org.example;

import org.apache.hc.client5.http.auth.AuthScope;
import org.apache.hc.client5.http.auth.CredentialsProvider;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.config.RequestConfig;
import org.apache.hc.client5.http.impl.auth.CredentialsProviderBuilder;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManagerBuilder;
import org.apache.hc.client5.http.ssl.NoopHostnameVerifier;
import org.apache.hc.client5.http.ssl.SSLConnectionSocketFactoryBuilder;
import org.apache.hc.client5.http.ssl.TrustAllStrategy;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.message.StatusLine;
import org.apache.hc.core5.ssl.SSLContextBuilder;

import java.util.Arrays;
import java.util.Properties;


public class Main {

    public static void main(final String[] args)throws Exception {
        final CredentialsProvider credsProvider = CredentialsProviderBuilder.create()
                .add(new AuthScope("unblock.oxylabs.io", 60000), "USERNAME", "PASSWORD".toCharArray())
                .build();
        final HttpHost target = new HttpHost("https", "ip.oxylabs.io", 443);
        final HttpHost proxy = new HttpHost("https", "unblock.oxylabs.io", 60000);
        try (final CloseableHttpClient httpclient = HttpClients.custom()
                .setDefaultCredentialsProvider(credsProvider)
                .setProxy(proxy)
                // Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
                .setConnectionManager(PoolingHttpClientConnectionManagerBuilder.create()
                        .setSSLSocketFactory(SSLConnectionSocketFactoryBuilder.create()
                                .setSslContext(SSLContextBuilder.create()
                                        .loadTrustMaterial(TrustAllStrategy.INSTANCE)
                                        .build())
                                .setHostnameVerifier(NoopHostnameVerifier.INSTANCE)
                                .build())
                        .build())
                .build()) {

            final RequestConfig config = RequestConfig.custom()
                    .build();
            final HttpGet request = new HttpGet("/location");
            request.addHeader("X-Oxylabs-Render","html");
            request.setConfig(config);

            System.out.println("Executing request " + request.getMethod() + " " + request.getUri() +
                    " via " + proxy + " headers: " + Arrays.toString(request.getHeaders()));

            httpclient.execute(target, request, response -> {
                System.out.println("----------------------------------------");
                System.out.println(request + "->" + new StatusLine(response));
                EntityUtils.consume(response.getEntity());
                return null;
            });
        }
    }
}
```

{% endtab %}
{% endtabs %}

**Extracción del HTML de un sitio web**

En este ejemplo, renderizaremos la página de inicio de YouTube y extraeremos el contenido de la página. Normalmente, la página de inicio de Youtube se vería así si se usa Web Unblocker sin renderización de Javascript:

<div align="left"><figure><img src="/files/7e32b2c11c830ec2f1e1c0da581e36b8e591b01f" alt=""><figcaption><p>Ejemplo de página de Youtube sin renderización de JavaScript</p></figcaption></figure></div>

Añadir el `"X-Oxylabs-Render: html"` encabezado, como se muestra en los ejemplos de abajo, habilitará la renderización de Javascript y devolverá el HTML de una página renderizada:

{% tabs %}
{% tab title="cURL" %}

```shell
curl -k -v -x https://unblock.oxylabs.io:60000 \
-U 'USERNAME:PASSWORD' \
'https://youtube.com' \\
-H 'X-Oxylabs-Render: html'
```

{% endtab %}

{% tab title="Python" %}

```python
import requests

# Usa aquí tus credenciales de Web Unblocker.
USERNAME, PASSWORD = 'YOUR_USERNAME', 'YOUR_PASSWORD'

# Define el diccionario de proxies.
proxies = {
  'http': f'http://{USERNAME}:{PASSWORD}@unblock.oxylabs.io:60000',
  'https': f'https://{USERNAME}:{PASSWORD}@unblock.oxylabs.io:60000',
}

headers = {
    'X-Oxylabs-Render': 'html'
}

response = requests.get(
    'https://youtube.com',
    verify=False,  # Es necesario ignorar el certificado
    proxies=proxies,
    headers=headers,
)

# Imprime la página de resultados en stdout
print(response.text)

# Guarda el HTML devuelto en el archivo result.html
with open('result.html', 'w') as f:
    f.write(response.text)
```

{% endtab %}

{% tab title="Node.js" %}

```javascript
import fetch from 'node-fetch';
import { HttpsProxyAgent } from 'https-proxy-agent';

const username = 'YOUR_USERNAME';
const password = 'YOUR_PASSWORD';

const agent = new HttpsProxyAgent(
  `https://${username}:${password}@unblock.oxylabs.io:60000`
);

// Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = 0;

const headers = {
   'X-Oxylabs-Render': 'html',
}

const response = await fetch('https://youtube.com', {
  method: 'get',
  headers: headers,
  agent: agent,
});

console.log(await response.text());
```

{% endtab %}

{% tab title="PHP" %}

```php
<?php
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, 'https://youtube.com');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_PROXY, 'https://unblock.oxylabs.io:60000');
curl_setopt($ch, CURLOPT_PROXYUSERPWD, 'YOUR_USERNAME' . ':' . 'YOUR_PASSWORD');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

curl_setopt_array($ch, [
    CURLOPT_HTTPHEADER  => [
        'X-Oxylabs-Render: html'
    ]
]);

$result = curl_exec($ch);
echo $result;

if (curl_errno($ch)) {
    echo 'Error:' . curl_error($ch);
}
curl_close($ch);
```

{% endtab %}

{% tab title="Golang" %}

```go
package main

import (
	"crypto/tls"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
)

func main() {
	const Username = "YOUR_USERNAME"
	const Password = "YOUR_PASSWORD"

	proxyUrl, _ := url.Parse(
		fmt.Sprintf(
			"https://%s:%s@unblock.oxylabs.io:60000",
			Username,
			Password,
		),
	)
	customTransport := &http.Transport{Proxy: http.ProxyURL(proxyUrl)}

	// Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
	customTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}

	client := &http.Client{Transport: customTransport}
	request, _ := http.NewRequest("GET",
		"https://youtube.com",
		nil,
	)
	
	// Add custom cookies
        request.Header.Add("X-Oxylabs-Render", "html")
        
	request.SetBasicAuth(Username, Password)
	response, _ := client.Do(request)

	responseText, _ := ioutil.ReadAll(response.Body)
	fmt.Println(string(responseText))
}

```

{% endtab %}

{% tab title="C#" %}

```csharp
using System;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

namespace OxyApi
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var webProxy = new WebProxy
            {
                Address = new Uri("https://unblock.oxylabs.io:60000"),
                BypassProxyOnLocal = false,
                UseDefaultCredentials = false,

                Credentials = new NetworkCredential(
                userName: "YOUR_USERNAME",
                password: "YOUR_PASSWORD"
                )
            };

            var httpClientHandler = new HttpClientHandler
            {
                Proxy = webProxy,
            };

            // Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
            httpClientHandler.ClientCertificateOptions = ClientCertificateOption.Manual;
            httpClientHandler.ServerCertificateCustomValidationCallback =
                (httpRequestMessage, cert, cetChain, policyErrors) =>
                {
                    return true;
                };


            var client = new HttpClient(handler: httpClientHandler, disposeHandler: true);
            
            // Agregar encabezado personalizado
            client.DefaultRequestHeaders.Add("X-Oxylabs-Render", "html");
            
            Uri baseUri = new Uri("https://youtube.com");
            client.BaseAddress = baseUri;

            var requestMessage = new HttpRequestMessage(HttpMethod.Get, "");

            var response = await client.SendAsync(requestMessage);
            var contents = await response.Content.ReadAsStringAsync();

            Console.WriteLine(contents);
        }
    }
}
```

{% endtab %}

{% tab title="Java" %}

```java
package org.example;

import org.apache.hc.client5.http.auth.AuthScope;
import org.apache.hc.client5.http.auth.CredentialsProvider;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.config.RequestConfig;
import org.apache.hc.client5.http.impl.auth.CredentialsProviderBuilder;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManagerBuilder;
import org.apache.hc.client5.http.ssl.NoopHostnameVerifier;
import org.apache.hc.client5.http.ssl.SSLConnectionSocketFactoryBuilder;
import org.apache.hc.client5.http.ssl.TrustAllStrategy;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.message.StatusLine;
import org.apache.hc.core5.ssl.SSLContextBuilder;

import java.util.Arrays;
import java.util.Properties;


public class Main {

    public static void main(final String[] args)throws Exception {
        final CredentialsProvider credsProvider = CredentialsProviderBuilder.create()
                .add(new AuthScope("unblock.oxylabs.io", 60000), "USERNAME", "PASSWORD".toCharArray())
                .build();
        final HttpHost target = new HttpHost("https", "youtube.com", 443);
        final HttpHost proxy = new HttpHost("https", "unblock.oxylabs.io", 60000);
        try (final CloseableHttpClient httpclient = HttpClients.custom()
                .setDefaultCredentialsProvider(credsProvider)
                .setProxy(proxy)
                // Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
                .setConnectionManager(PoolingHttpClientConnectionManagerBuilder.create()
                        .setSSLSocketFactory(SSLConnectionSocketFactoryBuilder.create()
                                .setSslContext(SSLContextBuilder.create()
                                        .loadTrustMaterial(TrustAllStrategy.INSTANCE)
                                        .build())
                                .setHostnameVerifier(NoopHostnameVerifier.INSTANCE)
                                .build())
                        .build())
                .build()) {

            final RequestConfig config = RequestConfig.custom()
                    .build();
            final HttpGet request = new HttpGet("/");
            request.addHeader("X-Oxylabs-Render","html");
            request.setConfig(config);

            System.out.println("Executing request " + request.getMethod() + " " + request.getUri() +
                    " via " + proxy + " headers: " + Arrays.toString(request.getHeaders()));

            httpclient.execute(target, request, response -> {
                System.out.println("----------------------------------------");
                System.out.println(request + "->" + new StatusLine(response));
                EntityUtils.consume(response.getEntity());
                return null;
            });
        }
    }
}
```

{% endtab %}
{% endtabs %}

El archivo HTML abierto en un navegador debería verse así:

<figure><img src="/files/6ea2e3344130f4af458a2cf0fb64d04ea708cfd4" alt=""><figcaption></figcaption></figure>

**Obtener una captura de pantalla de una página completamente renderizada**

Para obtener una captura de pantalla en formato PNG en lugar del HTML de la página, es necesario proporcionar el `"X-Oxylabs-Render: png"` encabezado.&#x20;

{% tabs %}
{% tab title="cURL" %}

```shell
curl -k -v -x https://unblock.oxylabs.io:60000 \
-U 'USERNAME:PASSWORD' \
'https://youtube.com' \\
-H 'X-Oxylabs-Render: png' > rendered_page.png
```

{% endtab %}

{% tab title="Python" %}

```python
import requests

# Usa aquí tus credenciales de Web Unblocker.
USERNAME, PASSWORD = 'YOUR_USERNAME', 'YOUR_PASSWORD'

# Define el diccionario de proxies.
proxies = {
  'http': f'http://{USERNAME}:{PASSWORD}@unblock.oxylabs.io:60000',
  'https': f'https://{USERNAME}:{PASSWORD}@unblock.oxylabs.io:60000',
}

headers = {
    'X-Oxylabs-Render': 'png'
}

response = requests.get(
    'https://youtube.com',
    verify=False,  # Es necesario ignorar el certificado
    proxies=proxies,
    headers=headers,
)

# Guardar captura de pantalla como archivo PNG
with open('rendered_page.png', 'wb') as f:
  f.write(response.content)
```

{% endtab %}

{% tab title="Node.js" %}

```javascript
import fs from 'fs';
import fetch from 'node-fetch';
import { HttpsProxyAgent } from 'https-proxy-agent';

const username = 'YOUR_USERNAME';
const password = 'YOUR_PASSWORD';

const agent = new HttpsProxyAgent(
  `https://${username}:${password}@unblock.oxylabs.io:60000`
);

// Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = 0;

const headers = {
   'X-Oxylabs-Render': 'png',
}

await fetch('https://youtube.com', {
  method: 'get',
  headers: headers,
  agent: agent,
}).then(res => 
  res.body.pipe(fs.createWriteStream('./rendered_page.png'))
  );

console.log('Image was saved');
```

{% endtab %}

{% tab title="PHP" %}

```php
<?php
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, 'https://youtube.com');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_PROXY, 'https://unblock.oxylabs.io:60000');
curl_setopt($ch, CURLOPT_PROXYUSERPWD, 'YOUR_USERNAME' . ':' . 'YOUR_PASSWORD');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

curl_setopt_array($ch, [
    CURLOPT_HTTPHEADER  => [
        'X-Oxylabs-Render: png'
    ]
]);

$result = curl_exec($ch);

if (curl_errno($ch)) {
    echo 'Error:' . curl_error($ch);
}
curl_close ($ch);

if(file_exists('rendered_page.png')){
    unlink('rendered_page.png');
}
$fp = fopen('rendered_page.png','wb');
fwrite($fp, $result);
fclose($fp);

```

{% endtab %}

{% tab title="Golang" %}

```go
package main

import (
	"crypto/tls"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
)

func main() {
	const Username = "YOUR_USERNAME"
	const Password = "YOUR_PASSWORD"

	proxyUrl, _ := url.Parse(
		fmt.Sprintf(
			"https://%s:%s@unblock.oxylabs.io:60000",
			Username,
			Password,
		),
	)
	customTransport := &http.Transport{Proxy: http.ProxyURL(proxyUrl)}

	// Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
	customTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}

	client := &http.Client{Transport: customTransport}
	request, _ := http.NewRequest("GET",
		"https://youtube.com",
		nil,
	)
	
	// Add custom cookies
        request.Header.Add("X-Oxylabs-Render", "png")
        
	request.SetBasicAuth(Username, Password)
	response, _ := client.Do(request)
	
	responseData, _ := ioutil.ReadAll(response.Body)
	response.Body.Close()
	ioutil.WriteFile("rendered_page.png", responseData, 0666)

	log.Println("Image was saved")
}

```

{% endtab %}

{% tab title="C#" %}

<pre class="language-csharp"><code class="lang-csharp">using System;
using System.Net;
using System.Net.Http;
using System.Drawing;
using System.IO;
using System.Threading.Tasks;

namespace OxyApi
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var webProxy = new WebProxy
            {
                Address = new Uri("https://unblock.oxylabs.io:60000"),
                BypassProxyOnLocal = false,
                UseDefaultCredentials = false,

                Credentials = new NetworkCredential(
                userName: "YOUR_USERNAME",
                password: "YOUR_PASSWORD"
                )
            };

            var httpClientHandler = new HttpClientHandler
            {
                Proxy = webProxy,
            };

            // Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
            httpClientHandler.ClientCertificateOptions = ClientCertificateOption.Manual;
            httpClientHandler.ServerCertificateCustomValidationCallback =
                (httpRequestMessage, cert, cetChain, policyErrors) =>
                {
                    return true;
                };


            var client = new HttpClient(handler: httpClientHandler, disposeHandler: true);
            
            // Agregar encabezado personalizado
            client.DefaultRequestHeaders.Add("X-Oxylabs-Render", "png");
            
            Uri baseUri = new Uri("https://youtube.com");
            client.BaseAddress = baseUri;

            var requestMessage = new HttpRequestMessage(HttpMethod.Get, "");

            var response = await client.SendAsync(requestMessage);
<strong>            byte[] bytes = await response.Content.ReadAsByteArrayAsync();
</strong>
            using (Image image = Image.FromStream(new MemoryStream(bytes)))
            {
                image.Save("rendered_page.png");
            }
        }
    }
}
</code></pre>

{% endtab %}

{% tab title="Java" %}

```java
package org.example;

import okhttp3.Authenticator;
import okhttp3.Credentials;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import javax.net.ssl.*;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.util.concurrent.TimeUnit;
import java.io.File;
import org.apache.commons.io.FileUtils;

public class App implements Runnable
{
    private static final String AUTHORIZATION_HEADER = "Proxy-Authorization";
    public static final String USERNAME = "YOUR_USERNAME";
    public static final String PASSWORD = "YOUR_PASSWORD";

    public void run() {
        Authenticator authenticator = (route, response) -> {
            String credential = Credentials.basic(USERNAME, PASSWORD);

            return response
                    .request()
                    .newBuilder()
                    .header(AUTHORIZATION_HEADER, credential)
                    .build();
        };

        OkHttpClient.Builder builder = new OkHttpClient.Builder()
                .readTimeout(180, TimeUnit.SECONDS)
                .writeTimeout(180, TimeUnit.SECONDS);

        // Recomendamos aceptar nuestro certificado en lugar de permitir tráfico inseguro (http)
        this.disableSSLCertificateChecking(builder);

        Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("unblock.oxylabs.io", 60000));
        OkHttpClient client = builder
                .proxy(proxy)
                .proxyAuthenticator(authenticator)
                .build();

        var request = new Request.Builder()
                .url("https://youtube.com")
                .addHeader("X-Oxylabs-Render", "png")
                .get()
                .build();

        try (var response = client.newCall(request).execute()) {
            assert response.body() != null;
            okhttp3.ResponseBody body = response.body();
            if (body != null) {
                byte[] bytes = body.bytes();
                FileUtils.writeByteArrayToFile(new File("rendered_page.png"), bytes);
            }
        } catch (Exception exception) {
            exception.printStackTrace();
            System.exit(1);
        }

        System.exit(0);
    }

    private void disableSSLCertificateChecking(OkHttpClient.Builder builder) {
        TrustManager[] trustManagers = new TrustManager[]{
                new X509TrustManager() {
                    @Override
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        return new java.security.cert.X509Certificate[]{};
                    }

                    @Override
                    public void checkServerTrusted(java.security.cert.X509Certificate[] x509Certificates, String authType) {
                    }

                    @Override
                    public void checkClientTrusted(java.security.cert.X509Certificate[] x509Certificates, String authType) {
                    }
                }
        };

        try {
            HttpsURLConnection.setDefaultHostnameVerifier((s, sslSession) -> true);
            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, trustManagers, new java.security.SecureRandom());
            HttpsURLConnection.setDefaultSSLSocketFactory(sslContext.getSocketFactory());

            builder.sslSocketFactory(sslContext.getSocketFactory(), (X509TrustManager) trustManagers[0]);
        } catch (Exception exception) {
            exception.printStackTrace();
            System.exit(1);
        }

        builder.hostnameVerifier((hostname, session) -> true);
    }

    public static void main(String[] args) {
        new Thread(new App()).start();
    }
}

```

{% endtab %}
{% endtabs %}

La respuesta contendrá bytes sin procesar de una imagen que se puede guardar en formato PNG y abrir como en el siguiente ejemplo:

<figure><img src="/files/6df0104089890e35270e7c31e834d4a8fbf35897" alt=""><figcaption><p>Ejemplo de página de Youtube como captura de pantalla en formato PNG</p></figcaption></figure>

## Forzar el renderizado en páginas específicas

Para una extracción exitosa, algunos tipos de páginas de dominios específicos requieren renderizado debido a su contenido dinámico. Nuestro sistema aplica automáticamente el renderizado para estas páginas, incluso si el usuario no lo establece explícitamente.

{% hint style="warning" %}
Tenga en cuenta que los trabajos renderizados consumen más tráfico que los trabajos no renderizados.
{% endhint %}

Queremos que nuestros usuarios sean plenamente conscientes de esto al extraer las siguientes páginas:

{% file src="/files/67dc18516d8938fed07497f121abb8d53cb4d8bf" %}

Este enfoque ofrece la mejor experiencia posible de extracción, garantizando la precisión y fiabilidad de los datos de estas páginas exigentes.&#x20;

Si deseas desactivar la renderización, envía el encabezado de renderización sin un valor

```
X-oxylabs-render: 
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developers.oxylabs.io/products/es/web-unblocker/custom-browser-instructions/javascript-rendering.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.