Merge PDF

Merge multiple PDF files into a single PDF document.

Try it live: Merge PDF → API Tester — send a real request from your browser.

POST /v1/pdf/merge

The total combined size of all input file URls must not exceed 2 GB. Requests that exceed this limit will not be processed.

Attributes

Attributes are case-sensitive and should be inside JSON for POST request. for example: { "url": "https://example.com/file1.pdf" }

Attribute	Type	Required	Default	Description
url	string	Yes	-	URLs to the source file url attribute. If you use multiple URLs, please separate them with a ,
callback	string	No	-	The callback URL (or Webhook) used to receive the POST data. see Webhooks & Callbacks. This is only applicable when async is set to true.
httpusername	string	No	-	HTTP auth user name if required to access source URL.
httppassword	string	No	-	HTTP auth password if required to access source URL.
async	boolean	No	false	Set async to true for long processes to run in the background, API will then return a jobId which you can use with the Background Job Check endpoint. Also see Webhooks & Callbacks
name	string	No	-	File name for the generated output, the input must be in string format.
expiration	integer	No	60	Set the expiration time for the output link in minutes. After this specified duration, any generated output file(s) will be automatically deleted from PDF.co Temporary Files Storage. The maximum duration for link expiration varies based on your current subscription plan. To store permanent input files (e.g. re-usable images, pdf templates, documents) consider using PDF.co Built-In Files Storage.
profiles	object	No	-	See Profiles for more information.
outputDataFormat	string	No	-	If you require your output as base64 format, set this to base64
RenameMatchingFieldsDuringMerge	boolean	No	true	This feature enables the renaming of field names during the merging of PDF files which contain forms. If set to false, it will retain the original field names. This is helpful for merged PDF forms with identical field names when the customer wants to auto-fill the identical field names in other pages.
GenerateBookmarks	boolean	No	false	This adds bookmarks to the merged document with names assigned to every merged document in the same order:
zipIncludeFilter	string	No	-	You can control which files to include and exclude from input zip files with a profiles.
zipExcludeFilter	string	No	-	zipIncludeFilter and zipExcludeFilter support * and ? wildcards.
MergedDocumentTitle	string	No	Title of the first document	Specifies a custom title for the merged document. Overrides the title of the first document during the merge process.
DataEncryptionAlgorithm	string	No	-	Controls the encryption algorithm used for data encryption. See User-Controlled Encryption for more information. The available algorithms are: AES128, AES192, AES256.
DataEncryptionKey	string	No	-	Controls the encryption key used for data encryption. See User-Controlled Encryption for more information.
DataEncryptionIV	string	No	-	Controls the encryption IV used for data encryption. See User-Controlled Encryption for more information.
DataDecryptionAlgorithm	string	No	-	Controls the decryption algorithm used for data decryption. See User-Controlled Encryption for more information. The available algorithms are: AES128, AES192, AES256.
DataDecryptionKey	string	No	-	Controls the decryption key used for data decryption. See User-Controlled Encryption for more information.
DataDecryptionIV	string	No	-	Controls the decryption IV used for data decryption. See User-Controlled Encryption for more information.

Rename Matching Fields

This feature enables the renaming of field names during the merging of PDF files which contain forms. If set to false, it will retain the original field names. This is helpful for merged PDF forms with identical field names when the customer wants to auto-fill the identical field names in other pages.

{
 "profiles": "{ 'RenameMatchingFieldsDuringMerge': false }"
}

Generate Bookmarks

This adds bookmarks to the merged document with names assigned to every merged document in the same order:

{
 "profiles": "{'GenerateBookmarks': true, 'BookmarkTitles': [ 'BookmarkName1', 'BookmarkName2', 'BookmarkName3' ] }"
}

Include / Exclude from ZIPS

You can control which files to include and exclude from input zip files with a profiles.

// include PDF, XLS and XLSX files
{
 "profiles": "{ 'zipIncludeFilter': '*.pdf,*.xls*' }"
}

// exclude DOC, DOCX, XLS and XLSX files
{
 "profiles": "{ 'zipExcludeFilter': '*.doc*,*.xls*' }"
}

zipIncludeFilter and zipExcludeFilter support * and ? wildcards.

Change Document Title

You can chnage the document title during a merge with the following:

{
 "profiles": "{ 'MergedDocumentTitle': 'New Title' }"
}

Query parameters

No query parameters accepted.

Responses

Parameter	Type	Description
url	string	Direct URL to the final PDF file stored in S3.
outputLinkValidTill	string	Timestamp indicating when the output link will expire
pageCount	integer	Number of pages in the PDF document.
error	boolean	Indicates whether an error occurred (false means success)
status	string	Status code of the request (200, 404, 500, etc.). For more information, see Response Codes.
name	string	Name of the output file
credits	integer	Number of credits consumed by the request
remainingCredits	integer	Number of credits remaining in the account
duration	integer	Time taken for the operation in milliseconds

Example Payload

To see the request size limits, please refer to the Request Size Limits.

{
  "url": "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample1.pdf,https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample2.pdf",
  "async": false
}

Example Response

To see the main response codes, please refer to the Response Codes page.

{
  "url": "https://pdf-temp-files.s3.amazonaws.com/3ec287356c0b4e02b5231354f94086f2/result.pdf",
  "error": false,
  "status": 200,
  "name": "result.pdf",
  "remainingCredits": 98465
}

Inconsistent URL Encoding in cURL Output: When using cURL to make API requests, the output JSON may show URL characters encoded as Unicode escape sequences. For example, the ampersand character (&) may appear as \u0026 in the cURL output. This is normal JSON encoding behavior and does not affect the validity of the URL. The URL will function correctly when used, as JSON parsers automatically decode these escape sequences. If you’re parsing the response programmatically, your JSON parser will handle this conversion automatically.

Code Samples

CURL

curl --location --request POST 'https://api.pdf.co/v1/pdf/merge' \
--header 'x-api-key: *******************' \
--header 'Content-Type: application/json' \
--data-raw '{
"url": "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample1.pdf,https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample2.pdf",
"async": false
}'

JavaScript/Node.js

var https = require("https");
var path = require("path");
var fs = require("fs");


// The authentication key (API Key).
// Get your own by registering at https://app.pdf.co
const API_KEY = "***********************************";


// Direct URLs of PDF files to merge
// You can also upload your own file into PDF.co and use it as url. Check "Upload File" samples for code snippets: https://github.com/pdfdotco/pdf-co-api-samples/tree/master/File%20Upload/    
const SourceFiles = [
    "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample1.pdf",
    "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample2.pdf"
];
// Destination PDF file name
const DestinationFile = "./result.pdf";

// Prepare request to `Merge PDF` API endpoint
var queryPath = `/v1/pdf/merge`;

// JSON payload for api request
var jsonPayload = JSON.stringify({
    name: path.basename(DestinationFile), url: SourceFiles.join(",")
});

var reqOptions = {
    host: "api.pdf.co",
    method: "POST",
    path: queryPath,
    headers: {
        "x-api-key": API_KEY,
        "Content-Type": "application/json",
        "Content-Length": Buffer.byteLength(jsonPayload, 'utf8')
    }
};

// Send request
var postRequest = https.request(reqOptions, (response) => {
    response.on("data", (d) => {
        // Parse JSON response
        var data = JSON.parse(d);
        if (data.error == false) {
            // Download PDF file
            var file = fs.createWriteStream(DestinationFile);
            https.get(data.url, (response2) => {
                response2.pipe(file)
                    .on("close", () => {
                        console.log(`Generated PDF file saved as "${DestinationFile}" file.`);
                    });
            });
        }
        else {
            // Service reported error
            console.log(data.message);
        }
    });
}).on("error", (e) => {
    // Request error
    console.log(e);
});

// Write request data
postRequest.write(jsonPayload);
postRequest.end();

Python

import os
import requests # pip install requests

# The authentication key (API Key).
# Get your own by registering at https://app.pdf.co
API_KEY = "**********************************"

# Base URL for PDF.co Web API requests
BASE_URL = "https://api.pdf.co/v1"

# Source PDF files
SourceFile_1 = ".\\sample1.pdf"
SourceFile_2 = ".\\sample2.pdf"

# Destination PDF file name
DestinationFile = ".\\result.pdf"

def main(args = None):
    UploadedFileUrl_1 = uploadFile(SourceFile_1)
    UploadedFileUrl_2 = uploadFile(SourceFile_2)

    if (UploadedFileUrl_1 != None and UploadedFileUrl_2!= None):
        uploadedFileUrls = "{},{}".format(UploadedFileUrl_1, UploadedFileUrl_2)
        mergeFiles(uploadedFileUrls, DestinationFile)

def mergeFiles(uploadedFileUrls, destinationFile):
    """Perform Merge using PDF.co Web API"""

    # Prepare requests params as JSON
    parameters = {}
    parameters["name"] = os.path.basename(destinationFile)
    parameters["url"] = uploadedFileUrls

    # Prepare URL for 'Merge PDF' API request
    url = "{}/pdf/merge".format(BASE_URL)

    # Execute request and get response as JSON
    response = requests.post(url, data=parameters, headers={ "x-api-key": API_KEY })
    if (response.status_code == 200):
        json = response.json()

        if json["error"] == False:
            #  Get URL of result file
            resultFileUrl = json["url"]            
            # Download result file
            r = requests.get(resultFileUrl, stream=True)
            if (r.status_code == 200):
                with open(destinationFile, 'wb') as file:
                    for chunk in r:
                        file.write(chunk)
                print(f"Result file saved as \"{destinationFile}\" file.")
            else:
                print(f"Request error: {response.status_code} {response.reason}")
        else:
            # Show service reported error
            print(json["message"])
    else:
        print(f"Request error: {response.status_code} {response.reason}")


def uploadFile(fileName):
    """Uploads file to the cloud"""
    
    # 1. RETRIEVE PRESIGNED URL TO UPLOAD FILE.

    # Prepare URL for 'Get Presigned URL' API request
    url = "{}/file/upload/get-presigned-url?contenttype=application/octet-stream&name={}".format(
        BASE_URL, os.path.basename(fileName))
    
    # Execute request and get response as JSON
    response = requests.get(url, headers={ "x-api-key": API_KEY })
    if (response.status_code == 200):
        json = response.json()
        
        if json["error"] == False:
            # URL to use for file upload
            uploadUrl = json["presignedUrl"]
            # URL for future reference
            uploadedFileUrl = json["url"]

            # 2. UPLOAD FILE TO CLOUD.
            with open(fileName, 'rb') as file:
                requests.put(uploadUrl, data=file, headers={ "x-api-key": API_KEY, "content-type": "application/octet-stream" })

            return uploadedFileUrl
        else:
            # Show service reported error
            print(json["message"])    
    else:
        print(f"Request error: {response.status_code} {response.reason}")

    return None


if __name__ == '__main__':
    main()

C#

using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace PDFcoApiExample
{
  class Program
  {
    // The authentication key (API Key).
    // Get your own by registering at https://app.pdf.co
    const String API_KEY = "***********************************";
    
    // Direct URLs of PDF files to merge
    // You can also upload your own file into PDF.co and use it as url. Check "Upload File" samples for code snippets: https://github.com/pdfdotco/pdf-co-api-samples/tree/master/File%20Upload/						
    static string[] SourceFiles = {
      "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample1.pdf",
      "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample2.pdf" };
    // Destination PDF file name
    const string DestinationFile = @".\result.pdf";

    static void Main(string[] args)
    {
      // Create standard .NET web client instance
      WebClient webClient = new WebClient();

      // Set API Key
      webClient.Headers.Add("x-api-key", API_KEY);

      // Prepare URL for `Merge PDF` API call
      string url = "https://api.pdf.co/v1/pdf/merge";

      // Prepare requests params as JSON
      Dictionary<string, object> parameters = new Dictionary<string, object>();
      parameters.Add("name", Path.GetFileName(DestinationFile));
      parameters.Add("url", string.Join(",", SourceFiles));

      // Convert dictionary of params to JSON
      string jsonPayload = JsonConvert.SerializeObject(parameters);

      try
      {
        // Execute POST request with JSON payload
        string response = webClient.UploadString(url, jsonPayload);

        // Parse JSON response
        JObject json = JObject.Parse(response);

        if (json["error"].ToObject<bool>() == false)
        {
          // Get URL of generated PDF file
          string resultFileUrl = json["url"].ToString();

          // Download PDF file
          webClient.DownloadFile(resultFileUrl, DestinationFile);

          Console.WriteLine("Generated PDF file saved as \"{0}\" file.", DestinationFile);
        }
        else
        {
          Console.WriteLine(json["message"].ToString());
        }
      }
      catch (WebException e)
      {
        Console.WriteLine(e.ToString());
      }

      webClient.Dispose();

      Console.WriteLine();
      Console.WriteLine("Press any key...");
      Console.ReadKey();
    }
  }
}

Java

package com.company;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import okhttp3.*;

import java.io.*;
import java.net.*;
import java.nio.file.Path;
import java.nio.file.Paths;

public class Main
{
    // The authentication key (API Key).
    // Get your own by registering at https://app.pdf.co
    final static String API_KEY = "***********************************";

    // Direct URLs of PDF files to merge
    // You can also upload your own file into PDF.co and use it as url. Check "Upload File" samples for code snippets: https://github.com/pdfdotco/pdf-co-api-samples/tree/master/File%20Upload/    
  final static String[] SourceFiles = {
            "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample1.pdf",
            "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample2.pdf" };
    // Destination PDF file name
    final static Path DestinationFile = Paths.get(".\\result.pdf");


    public static void main(String[] args) throws IOException
    {
        // Create HTTP client instance
        OkHttpClient webClient = new OkHttpClient();

        // Prepare URL for `Merge PDF` API call
        String query = "https://api.pdf.co/v1/pdf/merge";

        // Make correctly escaped (encoded) URL
        URL url = null;
        try
        {
            url = new URI(null, query, null).toURL();
        }
        catch (URISyntaxException e)
        {
            e.printStackTrace();
        }

        // Create JSON payload
    String jsonPayload = String.format("{\"name\": \"%s\", \"url\": \"%s\"}",
                DestinationFile.getFileName(),
                String.join(",", SourceFiles));

        // Prepare request body
        RequestBody body = RequestBody.create(MediaType.parse("application/json"), jsonPayload);
        
        // Prepare request
        Request request = new Request.Builder()
            .url(url)
            .addHeader("x-api-key", API_KEY) // (!) Set API Key
            .addHeader("Content-Type", "application/json")
            .post(body)
            .build();
        
        // Execute request
        Response response = webClient.newCall(request).execute();
        

        if (response.code() == 200)
        {
            // Parse JSON response
            JsonObject json = new JsonParser().parse(response.body().string()).getAsJsonObject();

            boolean error = json.get("error").getAsBoolean();
            if (!error)
            {
                // Get URL of generated PDF file
                String resultFileUrl = json.get("url").getAsString();

                // Download PDF file
                downloadFile(webClient, resultFileUrl, DestinationFile.toFile());

                System.out.printf("Generated PDF file saved as \"%s\" file.", DestinationFile.toString());
            }
            else
            {
                // Display service reported error
                System.out.println(json.get("message").getAsString());
            }
        }
        else
        {
            // Display request error
            System.out.println(response.code() + " " + response.message());
        }
    }

    public static void downloadFile(OkHttpClient webClient, String url, File destinationFile) throws IOException
    {
        // Prepare request
        Request request = new Request.Builder()
                .url(url)
                .build();
        // Execute request
        Response response = webClient.newCall(request).execute();

        byte[] fileBytes = response.body().bytes();

        // Save downloaded bytes to file
        OutputStream output = new FileOutputStream(destinationFile);
        output.write(fileBytes);
        output.flush();
        output.close();

        response.close();
    }
}

PHP

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Cloud API asynchronous "PDF Merging" job example (allows to avoid timeout errors).</title>
</head>
<body>

<?php 

// Cloud API asynchronous "PDF Merging" job example.
// Allows to avoid timeout errors when processing huge or scanned PDF documents.


// The authentication key (API Key).
// Get your own by registering at https://app.pdf.co
$apiKey = "****************************************";

// Direct URLs of PDF files to merge. Check another example if you need to upload local files to the cloud.
// You can also upload your own file into PDF.co and use it as url. Check "Upload File" samples for code snippets: https://github.com/pdfdotco/pdf-co-api-samples/tree/master/File%20Upload/    
$sourceFiles = array(
    "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample1.pdf", 
    "https://pdfco-test-files.s3.us-west-2.amazonaws.com/pdf-merge/sample2.pdf");


// Prepare URL for `Merge PDF` API call
$url = "https://api.pdf.co/v1/pdf/merge";

// Prepare requests params
$parameters = array();
$parameters["url"] = join(",", $sourceFiles);
$parameters["async"] = true; // (!) Make asynchronous job

// Create Json payload
$data = json_encode($parameters);

// Create request
$curl = curl_init();
curl_setopt($curl, CURLOPT_HTTPHEADER, array("x-api-key: " . $apiKey, "Content-type: application/json"));
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_POSTFIELDS, $data);

// Execute request
$result = curl_exec($curl);

if (curl_errno($curl) == 0)
{
    $status_code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
    
    if ($status_code == 200)
    {
        $json = json_decode($result, true);
        
        if (!isset($json["error"]) || $json["error"] == false)
        {
            // URL of generated PDF file that will available after the job completion
            $resultFileUrl = $json["url"];
            // Asynchronous job ID
            $jobId = $json["jobId"];
            
            // Check the job status in a loop
            do
            {
                $status = CheckJobStatus($jobId, $apiKey); // Possible statuses: "working", "failed", "aborted", "success".
                
                // Display timestamp and status (for demo purposes)
                echo "<p>" . date(DATE_RFC2822) . ": " . $status . "</p>";
                
                if ($status == "success")
                {
                    // Display link to the file with conversion results
                    echo "<div><h2>Conversion Result:</h2><a href='" . $resultFileUrl . "' target='_blank'>" . $resultFileUrl . "</a></div>";
                    break;
                }
                else if ($status == "working")
                {
                    // Pause for a few seconds
                    sleep(3);
                }
                else 
                {
                    echo $status . "<br/>";
                    break;
                }
            }
            while (true);
        }
        else
        {
            // Display service reported error
            echo "<p>Error: " . $json["message"] . "</p>"; 
        }
    }
    else
    {
        // Display request error
        echo "<p>Status code: " . $status_code . "</p>"; 
        echo "<p>" . $result . "</p>"; 
    }
}
else
{
    // Display CURL error
    echo "Error: " . curl_error($curl);
}

// Cleanup
curl_close($curl);


function CheckJobStatus($jobId, $apiKey)
{
    $status = null;
    
  // Create URL
    $url = "https://api.pdf.co/v1/job/check";
    
    // Prepare requests params
    $parameters = array();
    $parameters["jobid"] = $jobId;

    // Create Json payload
    $data = json_encode($parameters);

    // Create request
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_HTTPHEADER, array("x-api-key: " . $apiKey, "Content-type: application/json"));
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
    
    // Execute request
    $result = curl_exec($curl);
    
    if (curl_errno($curl) == 0)
    {
        $status_code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
        
        if ($status_code == 200)
        {
            $json = json_decode($result, true);
        
            if (!isset($json["error"]) || $json["error"] == false)
            {
                $status = $json["status"];
            }
            else
            {
                // Display service reported error
                echo "<p>Error: " . $json["message"] . "</p>"; 
            }
        }
        else
        {
            // Display request error
            echo "<p>Status code: " . $status_code . "</p>"; 
            echo "<p>" . $result . "</p>"; 
        }
    }
    else
    {
        // Display CURL error
        echo "Error: " . curl_error($curl);
    }
    
    // Cleanup
    curl_close($curl);
    
    return $status;
}

?>

</body>
</html>