Rejecting Undesired Requests

You can use rejectResourceTypes and rejectRequestPattern to block undesired content, resources and requests.

Rest API (Without Stealth)

Here’s the request in the specified format, with examples for curl, JavaScript, Python, Java and C#.

Bot detection

Browserless recommends using our REST API to generate PDFs, unless you need to get past bot detectors.

JSON payload

// Will reject any images and .css files
{
  "url": "https://browserless.io/"
  "rejectResourceTypes": ["image"],
  "rejectRequestPattern": ["/^.*\\.(css)"]
}

cURL

curl -X POST \
  https://production-sfo.browserless.io/pdf?token=YOUR_API_TOKEN_HERE \
  -H 'Cache-Control: no-cache' \
  -H 'Content-Type': 'application/json' \
  -d '{
  "url": "https://browserless.io/",
  "rejectResourceTypes": ["image"],
  "rejectRequestPattern": ["/^.*\\.(css)"]
}'

Javascript

import fs from 'fs/promises';

const TOKEN = "YOUR_API_TOKEN_HERE";
const url = `https://production-sfo.browserless.io/pdf?token=${TOKEN}`;
const headers = {
  "Cache-Control": "no-cache",
  "Content-Type": "application/json"
};

const data = {
  url: "https://browserless.io/",
  rejectResourceTypes: ["image"],
  rejectRequestPattern: ["^.*\\.(css)"]
};

const generatePDF = async () => {
  const response = await fetch(url, {
    method: 'POST',
    headers: headers,
    body: JSON.stringify(data)
  });

  const pdfBuffer = await response.arrayBuffer();
  await fs.writeFile("output.pdf", Buffer.from(pdfBuffer));
  console.log("PDF saved as output.pdf");
};

generatePDF();

Python

import requests

TOKEN = "YOUR_API_TOKEN_HERE"
url = f"https://production-sfo.browserless.io/pdf?token={TOKEN}"
headers = {
    "Cache-Control": "no-cache",
    "Content-Type": "application/json"
}

data = {
    "url": "https://browserless.io/",
    "rejectResourceTypes": ["image"],
    "rejectRequestPattern": ["^.*\\.(css)"]
}

response = requests.post(url, headers=headers, json=data)

with open("output.pdf", "wb") as file:
    file.write(response.content)

print("PDF saved as output.pdf")

Java

import java.io.*;
import java.net.URI;
import java.net.http.*;
import java.nio.file.*;

public class GeneratePDFWithRejections {
    public static void main(String[] args) {
        String TOKEN = "YOUR_API_TOKEN_HERE";
        String url = "https://production-sfo.browserless.io/pdf?token=" + TOKEN;

        String jsonData = """
        {
            "url": "https://browserless.io/",
            "rejectResourceTypes": ["image"],
            "rejectRequestPattern": ["^.*\\\\.(css)"]
        }
        """;

        HttpClient client = HttpClient.newHttpClient();

        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create(url))
            .header("Cache-Control", "no-cache")
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(jsonData))
            .build();

        try {
            HttpResponse<InputStream> response = client.send(request, HttpResponse.BodyHandlers.ofInputStream());
            Files.copy(response.body(), Paths.get("output.pdf"), StandardCopyOption.REPLACE_EXISTING);
            System.out.println("PDF saved as output.pdf");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

C#

using System;
using System.IO;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

class Program
{
    static async Task Main(string[] args)
    {
        string TOKEN = "YOUR_API_TOKEN_HERE";
        string url = $"https://production-sfo.browserless.io/pdf?token={TOKEN}";

        string jsonData = @"
          {
              ""url"": ""https://browserless.io/"",
              ""rejectResourceTypes"": [""image""],
              ""rejectRequestPattern"": [""^.*\\\\.(css)""]
          }";

        using var client = new HttpClient();

        var request = new HttpRequestMessage(HttpMethod.Post, url)
        {
            Content = new StringContent(jsonData, Encoding.UTF8, "application/json")
        };

        request.Headers.Add("Cache-Control", "no-cache");

        try
        {
            var response = await client.SendAsync(request);
            response.EnsureSuccessStatusCode();
            var pdfBytes = await response.Content.ReadAsByteArrayAsync();

            await File.WriteAllBytesAsync("output.pdf", pdfBytes);
            Console.WriteLine("PDF saved as output.pdf");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error: {ex.Message}");
        }
    }
}

BQL (Stealth)

If the /pdf API is getting blocked by bot detectors, then we would recommend trying BrowserQL.

BQL Query

mutation PDF {
  reject(type: [image, stylesheet]) {
    enabled
    time
  }

  goto(url: "https://browserless.io/") {
    status
  }

  pdf(displayHeaderFooter: true, printBackground: false, format: a0) {
    base64
  }
}

cURL

curl --request POST \
  --url 'https://production-sfo.browserless.io/chromium/bql?token=YOUR_API_TOKEN_HERE' \
  --header 'Content-Type: application/json' \
  --data '{"query":"mutation PDF {\n  reject(type: [image, stylesheet]) {\n    enabled\n    time\n  }\n\n  goto(url: \"https://browserless.io/\") {\n    status\n  }\n\n  pdf(displayHeaderFooter: true, printBackground: false, format: a0) {\n    base64\n  }\n}","variables":"","operationName":"PDF"}'

Javascript

const endpoint = "https://production-sfo.browserless.io/chromium/bql";
const token = "YOUR_API_TOKEN_HERE";

const options = {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({"query":"mutation PDF {\n  reject(type: [image, stylesheet]) {\n    enabled\n    time\n  }\n\n  goto(url: \"https://browserless.io/\") {\n    status\n  }\n\n  pdf(displayHeaderFooter: true, printBackground: false, format: a0) {\n    base64\n  }\n}","variables":"","operationName":"PDF"})
};

const url = `${endpoint}?token=${token}`;
const response = await fetch(url, options);
const data = await response.json();

console.log(data);

Python

import requests

endpoint = "https://production-sfo.browserless.io/chromium/bql"
query_string = {
    "token": "YOUR_API_TOKEN_HERE",
}
headers = {
    "Content-Type": "application/json",
}
payload = {
    "query": "mutation PDF {\n  reject(type: [image, stylesheet]) {\n    enabled\n    time\n  }\n\n  goto(url: \"https://browserless.io/\") {\n    status\n  }\n\n  pdf(displayHeaderFooter: true, printBackground: false, format: a0) {\n    base64\n  }\n}",
    "variables": None,
    "operationName": "PDF",
}

response = requests.post(endpoint, params=query_string, headers=headers, json=payload)
print(response.json())

Java

String url = "https://production-sfo.browserless.io/chromium/bql";
String token = "YOUR_API_TOKEN_HERE";
String endpoint = String.format("%s?token=%s%s%s", url, token);

HttpResponse<String> response = Unirest.post(endpoint)
    .header("Content-Type", "application/json")
    .body({"query":"mutation PDF {\n  reject(type: [image, stylesheet]) {\n    enabled\n    time\n  }\n\n  goto(url: \"https://browserless.io/\") {\n    status\n  }\n\n  pdf(displayHeaderFooter: true, printBackground: false, format: a0) {\n    base64\n  }\n}","variables":"","operationName":"PDF"})
    .asString();

C#

string url = "https://production-sfo.browserless.io/chromium/bql";
string token = "YOUR_API_TOKEN_HERE";
string endpoint = $"{url}?token={token}";

var payload = new
{
    query = @"mutation PDF {
  reject(type: [image, stylesheet]) {
    enabled
    time
  }

  goto(url: ""https://browserless.io/"") {
    status
  }

  pdf(displayHeaderFooter: true, printBackground: false, format: a0) {
    base64
  }
}",
    variables = "",
    operationName = "PDF"
};

using (var client = new HttpClient())
{
    var jsonPayload = System.Text.Json.JsonSerializer.Serialize(payload);
    var content = new StringContent(jsonPayload, Encoding.UTF8, "application/json");

    var response = await client.PostAsync(endpoint, content);
    string responseBody = await response.Content.ReadAsStringAsync();
    
    Console.WriteLine(responseBody);
}

BQL Schemas

For more details on BQL mutations, refer to the BrowserQL Schema reference pages.