Pdf Merge API

SelectPdf Pdf Merge REST API is an online solution that lets you merge local or remote PDFs into a final PDF document. The API is easy to use, the integration can be done in a few minutes with only a few lines of code.

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The free trial key for the online API is valid for 7 days and it includes 200 conversions.

Features

Usage

It’s very easy to use SelectPdf Pdf Merge REST API. All you need is a license key and you will be able to merge your PDFs in an instant. If you want to see how to do this in PHP, Java, Ruby, Python, Perl, Node.JS, C# or VB.net, click here to go directly to the coding examples.

Here is a basic usage example using a POST request:

Options

Mandatory Parameters

SelectPdf Pdf Merge REST API has only 2 mandatory parameters. The rest of the parameters are optional. When they are missing, the default value is used.

Merged PDF documents

PDF documents that will be merged can be specified using public urls or local files can be uploaded. There is a naming convention for these files:

For example, if 4 files are merged, the parameters sent to the API should look like this:

Pdf Options

Use the following parameters to control the PDF document information, security and the look when the document is opened in a client PDF viewer.

Return Codes

Our API returns HTTP response codes, which you can check to see if the conversion was successful or not. Here is the list of HTTP codes used by SelectPdf REST API:

Remarks

Code Examples

Pdf Merge in PHP

<?php
require("SelectPdf.Api.php");

$testUrl = "https://selectpdf.com/demo/files/selectpdf.pdf";
$testPdf = "Input.pdf";
$localFile = "Result.pdf";
$apiKey = "Your API key here";

echo ("This is SelectPdf-" . SelectPdf\Api\ApiClient::CLIENT_VERSION . ".\n");

try {
    $client = new SelectPdf\Api\PdfMergeClient($apiKey);

    // specify the pdf files that will be merged (order is preserved in the final pdf)
    $client
        ->addFile($testPdf)        // add PDF from local file
        ->addUrlFile($testUrl)     // add PDF from public url
        // ->addFile($testPdf, "pdf_password")     // protected PDF from local file
        // ->addUrlFile($testUrl, "pdf_password")  // protected PDF from public url
    ;

    echo ("Starting pdf merge ...\n");

    // merge pdfs to local file
    $client->saveToFile($localFile);

    // merge pdfs to memory
    // $pdf = $client->save();

    echo ("Finished! Number of pages: " . $client->getNumberOfPages() . ".\n");

    // get API usage
    $usageClient = new \SelectPdf\Api\UsageClient($apiKey);
    $usage = $usageClient->getUsage(false);
    echo ("Conversions remained this month: " . $usage["available"] . ".\n");
}
catch (Exception $ex) {
    echo ("An error occurred: " . $ex . ".\n");
}
?>

// Code snippet uses the SelectPdf API Client library for PHP.

Pdf Merge in Java

package com.selectpdf;

public class PdfMerge {
    public static void main(String[] args) throws Exception {
        String testUrl = "https://selectpdf.com/demo/files/selectpdf.pdf";
        String testPdf = "Input.pdf";
        String localFile = "Result.pdf";
        String apiKey = "Your API key here";

        System.out.println(String.format("This is SelectPdf-%s.", ApiClient.CLIENT_VERSION));

        try {
            PdfMergeClient client = new PdfMergeClient(apiKey);

            // specify the pdf files that will be merged (order is preserved in the final pdf)
            client
                .addFile(testPdf)         // add PDF from local file
                .addUrlFile(testUrl)      // add PDF from public url
                // .addFile(testPdf, "pdf_password")    // protected PDF from local file
                // .addUrlFile(testUrl, "pdf_password") // protected PDF from public url
            ;

            System.out.println("Starting pdf merge...");

            // merge pdfs to local file
            client.saveToFile(localFile);

            // merge pdfs to memory
            // byte[] pdf = client.save();

            System.out.println(String.format("Finished! Number of pages: %d.", client.getNumberOfPages()));

            // get API usage
            UsageClient usageClient = new UsageClient(apiKey);
            String usage = usageClient.getUsage(false);
            System.out.printf("Usage details: %s.%n", usage);
        }
        catch (Exception ex) {
            System.out.println("An error occurred: " + ex.getMessage());
        }
    }
}

// Code snippet uses the SelectPdf API Client library for Java.

Pdf Merge in Ruby

require 'selectpdf'

$stdout.sync = true

print "This is SelectPdf-#{SelectPdf::CLIENT_VERSION}\n"

test_url = 'https://selectpdf.com/demo/files/selectpdf.pdf'
test_pdf = 'Input.pdf'
local_file = 'Result.pdf'
api_key = 'Your API key here'

begin
  client = SelectPdf::PdfMergeClient.new(api_key)

  # specify the pdf files that will be merged (order is preserved in the final pdf)
  client.add_file(test_pdf)        # add PDF from local file
  client.add_url_file(test_url)    # add PDF from public url
  # client.add_file(test_pdf, 'pdf_password')     # protected PDF from local file
  # client.add_url_file(test_url, 'pdf_password') # protected PDF from public url

  print "Starting pdf merge ...\n"

  # merge pdfs to local file
  client.save_to_file(local_file)

  # merge pdfs to memory
  # pdf = client.save

  print "Finished! Number of pages: #{client.number_of_pages}.\n"

  # get API usage
  usage_client = SelectPdf::UsageClient.new(api_key)
  usage = usage_client.get_usage(false)
  print('Conversions remained this month: ', usage['available'], "\n")
rescue SelectPdf::ApiException => e
  print("An error occurred: #{e}")
end

# Code snippet uses the SelectPdf API Client library for Ruby.

Pdf Merge in Python

# -*- coding: utf-8 -*-

import selectpdf

testUrl = "https://selectpdf.com/demo/files/selectpdf.pdf"
testPdf = "Input.pdf"
localFile = "Result.pdf"
apiKey = "Your API key here"

print ("This is SelectPdf-{0}.".format(selectpdf.CLIENT_VERSION))

try:
    client = selectpdf.PdfMergeClient(apiKey)

    # specify the pdf files that will be merged (order is preserved in the final pdf)
    client.addFile(testPdf)        # add PDF from local file
    client.addUrlFile(testUrl)     # add PDF from public url
    # client.addFileWithPassword(testPdf, "pdf_password")     # protected PDF from local file
    # client.addUrlFileWithPassword(testUrl, "pdf_password")  # protected PDF from public url

    print ("Starting pdf merge ...")

    # merge pdfs to local file
    client.saveToFile(localFile)

    # merge pdfs to memory
    # pdf = client.save()

    print ("Finished! Number of pages: {0}.".format(client.getNumberOfPages()))

    # get API usage
    usageClient = selectpdf.UsageClient(apiKey)
    usage = usageClient.getUsage()
    print ("Conversions remained this month: {0}.".format(usage["available"]))

except selectpdf.ApiException as ex:
    print ("An error occurred: {0}.".format(ex.getMessage()))

# Code snippet uses the SelectPdf API Client library for Python.

Pdf Merge in C#

using System;
using SelectPdf.Api;

namespace Samples
{
    public class PdfMerge
    {
        public static void Main()
        {
            string testUrl = "https://selectpdf.com/demo/files/selectpdf.pdf";
            string testPdf = "Input.pdf";
            string localFile = "Result.pdf";
            string apiKey = "Your API key here";

            Console.WriteLine("This is SelectPdf-{0}.", ApiClient.CLIENT_VERSION);

            try
            {
                PdfMergeClient client = new PdfMergeClient(apiKey);

                // specify the pdf files that will be merged (order is preserved in the final pdf)
                client
                    .addFile(testPdf)         // add PDF from local file
                    .addUrlFile(testUrl)      // add PDF from public url
                    // .addFile(testPdf, "pdf_password")    // protected PDF from local file
                    // .addUrlFile(testUrl, "pdf_password") // protected PDF from public url
                ;

                Console.WriteLine("Starting pdf merge ...");

                // merge pdfs to local file
                client.saveToFile(localFile);

                // merge pdfs to memory
                // byte[] pdf = client.save();

                Console.WriteLine("Finished! Number of pages: {0}.", client.getNumberOfPages());

                // response telemetry (SDK 1.5.0+)
                Console.WriteLine("Mode: {0}, Execution: {1}.", client.Mode, client.ExecutionMode);
                Console.WriteLine("Credits remaining: {0} / {1}.",
                    client.CreditsRemaining, client.CreditsTotal);

                // get API usage
                UsageClient usageClient = new UsageClient(apiKey);
                UsageInformation usage = usageClient.getUsage(false);
                Console.WriteLine("Conversions remained this month: {0}.", usage.Available);
            }
            catch (ApiException ex)
            {
                Console.WriteLine("API error: {0}", ex.Message);
            }
            catch (Exception ex)
            {
                Console.WriteLine("An error occurred: " + ex.Message);
            }
        }
    }
}

// Code snippet uses the SelectPdf API Client library for .NET.

Pdf Merge in Go

There is no dedicated Go client library for the SelectPdf API. The example below uses Go’s standard library to POST a multipart/form-data request directly to the API endpoint.

package main

import (
    "bytes"
    "fmt"
    "io"
    "mime/multipart"
    "net/http"
    "os"
)

func main() {
    apiEndpoint := "https://selectpdf.com/api2/pdfmerge/"
    apiKey := "Your API key here"
    localPdf := "Input.pdf"
    remotePdf := "https://selectpdf.com/demo/files/selectpdf.pdf"
    outFile := "Result.pdf"

    body := &bytes.Buffer{}
    writer := multipart.NewWriter(body)

    // mandatory parameters
    _ = writer.WriteField("key", apiKey)
    _ = writer.WriteField("files_no", "2")

    // file 1 - local upload via file_1
    f, err := os.Open(localPdf)
    if err != nil { panic(err) }
    defer f.Close()
    part, err := writer.CreateFormFile("file_1", localPdf)
    if err != nil { panic(err) }
    if _, err := io.Copy(part, f); err != nil { panic(err) }

    // file 2 - remote pdf via url_2
    _ = writer.WriteField("url_2", remotePdf)

    // optional: pdf options
    _ = writer.WriteField("doc_title", "Merged document")
    // _ = writer.WriteField("password_1", "pdf_password") // password for file_1 if required
    // _ = writer.WriteField("user_password", "open_pass") // protect output PDF

    if err := writer.Close(); err != nil { panic(err) }

    req, err := http.NewRequest("POST", apiEndpoint, body)
    if err != nil { panic(err) }
    req.Header.Set("Content-Type", writer.FormDataContentType())

    resp, err := http.DefaultClient.Do(req)
    if err != nil { panic(err) }
    defer resp.Body.Close()

    if resp.StatusCode != http.StatusOK {
        msg, _ := io.ReadAll(resp.Body)
        fmt.Printf("API error %d: %s\n", resp.StatusCode, string(msg))
        return
    }

    out, err := os.Create(outFile)
    if err != nil { panic(err) }
    defer out.Close()
    if _, err := io.Copy(out, resp.Body); err != nil { panic(err) }

    fmt.Printf("Finished! Pages: %s. Saved to %s.\n",
        resp.Header.Get("X-SelectPdf-Pages"), outFile)
}

Pdf Merge in Node.js

var selectpdf = require('selectpdf');

console.log("This is SelectPdf-%s.", selectpdf.CLIENT_VERSION);

try {
    var testUrl = 'https://selectpdf.com/demo/files/selectpdf.pdf';
    var testPdf = 'Input.pdf';
    var localFile = 'Result.pdf';
    var apiKey = 'Your API key here';

    var client = new selectpdf.PdfMergeClient(apiKey);

    // specify the pdf files that will be merged (order is preserved in the final pdf)
    client
        .addFile(testPdf)         // add PDF from local file
        .addUrlFile(testUrl)      // add PDF from public url
        // .addFile(testPdf, "pdf_password")    // protected PDF from local file
        // .addUrlFile(testUrl, "pdf_password") // protected PDF from public url
    ;

    console.log('Starting pdf merge ...');

    // merge pdfs to local file
    client.saveToFile(localFile,
        function(err, fileName) {
            if (err) return console.error("An error occurred: " + err);
            console.log("Finished! Result is in file '" + fileName +
                "'. Number of pages: " + client.getNumberOfPages());

            var usageClient = new selectpdf.UsageClient(apiKey);
            usageClient.getUsage(false, function(err2, data) {
                if (err2) return console.error("Usage error: " + err2);
                console.log("Conversions remained this month: " + data["available"]);
            });
        }
    );

    // merge pdfs to memory
    /*
    client.save(function(err, pdf) {
        if (err) return console.error("An error occurred: " + err);
        console.log("Finished! Result is in variable 'pdf'. Pages: " + client.getNumberOfPages());
    });
    */
}
catch (ex) {
    console.log("An error occurred: " + ex);
}

// Code snippet uses the SelectPdf API Client library for Node.js.

Test SelectPdf PDF Merge online RESTful API Now

Request a Demo License Key for SelectPdf REST API right now. Feel free to ask any questions if needed.
The free trial key for the online API is valid for 7 days and it includes 200 conversions.

SelectPdf for Cloud’s platform independent Pdf Merge API is a true REST API that can be used with any language: .NET, Java, PHP, Ruby, Rails, Python, jQuery and many more. You can use it with any language or platform that supports REST. Almost all platforms and languages support REST and provide native REST clients to work with REST APIs. You do not need to worry about language or platform limitations. You can use it with any platform – web, desktop, mobile, and cloud. Try now for free the best API to Merge PDFs.