Image to PDF C# API

PSPDFKit API is an HTTP API that lets you convert various image formats into PDF. Use our C# image to PDF conversion API to convert JPG, PNG, and TIFF files to PDF.

Convert from

Convert to

PDF

Getting Started

The following section will walk you through how to best make use of all the functionality our Image to PDF API provides.

Converting a Single Image to PDF

Let’s start with the basics. The Image to PDF API allows you to convert any supported image file to a PDF.

The easiest way to use this is to convert a single image to a PDF. Place a page1.jpg file in the same folder as your code. You can use any image or use our provided sample page.

Run the code, and you’ll get a result.pdf with your image converted to a PDF.

Code to convert an image to PDF:

curl -X POST https://api.pspdfkit.com/build \
  -H "Authorization: Bearer your_api_key_here" \
  -o result.pdf \
  --fail \
  -F page1.jpg=@/path/to/page1.jpg \
  -F instructions='{
      "parts": [
        {
          "file": "page1.jpg"
        }
      ]
    }'
curl -X POST https://api.pspdfkit.com/build ^
  -H "Authorization: Bearer your_api_key_here" ^
  -o result.pdf ^
  --fail ^
  -F page1.jpg=@/path/to/page1.jpg ^
  -F instructions="{\"parts\": [{\"file\": \"page1.jpg\"}]}"
package com.example.pspdfkit;

import java.io.File;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;

import org.json.JSONArray;
import org.json.JSONObject;

import okhttp3.MediaType;
import okhttp3.MultipartBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public final class PspdfkitApiExample {
  public static void main(final String[] args) throws IOException {
    final RequestBody body = new MultipartBody.Builder()
      .setType(MultipartBody.FORM)
      .addFormDataPart(
        "page1.jpg",
        "/path/to/page1.jpg",
        RequestBody.create(
          new File("/path/to/page1.jpg"),
          MediaType.parse("image/jpeg")
        )
      )
      .addFormDataPart(
        "instructions",
        new JSONObject()
          .put("parts", new JSONArray()
            .put(new JSONObject()
              .put("file", "page1.jpg")
            )
          ).toString()
      )
      .build();

    final Request request = new Request.Builder()
      .url("https://api.pspdfkit.com/build")
      .method("POST", body)
      .addHeader("Authorization", "Bearer your_api_key_here")
      .build();

    final OkHttpClient client = new OkHttpClient()
      .newBuilder()
      .build();

    final Response response = client.newCall(request).execute();

    if (response.isSuccessful()) {
      Files.copy(
        response.body().byteStream(),
        FileSystems.getDefault().getPath("result.pdf"),
        StandardCopyOption.REPLACE_EXISTING
      );
    } else {
      // Handle the error
      throw new IOException(response.body().string());
    }
  }
}
using System;
using System.IO;
using System.Net;
using RestSharp;

namespace PspdfkitApiDemo
{
  class Program
  {
    static void Main(string[] args)
    {
      var client = new RestClient("https://api.pspdfkit.com/build");

      var request = new RestRequest(Method.POST)
        .AddHeader("Authorization", "Bearer your_api_key_here")
        .AddFile("page1.jpg", "/path/to/page1.jpg")
        .AddParameter("instructions", new JsonObject
        {
          ["parts"] = new JsonArray
          {
            new JsonObject
            {
              ["file"] = "page1.jpg"
            }
          }
        }.ToString());

      request.AdvancedResponseWriter = (responseStream, response) =>
      {
        if (response.StatusCode == HttpStatusCode.OK)
        {
          using (responseStream)
          {
            using var outputFileWriter = File.OpenWrite("result.pdf");
            responseStream.CopyTo(outputFileWriter);
          }
        }
        else
        {
          var responseStreamReader = new StreamReader(responseStream);
          Console.Write(responseStreamReader.ReadToEnd());
        }
      };

      client.Execute(request);
    }
  }
}
// This code requires Node.js. Do not run this code directly in a web browser.

const axios = require('axios')
const FormData = require('form-data')
const fs = require('fs')

const formData = new FormData()
formData.append('instructions', JSON.stringify({
  parts: [
    {
      file: "page1.jpg"
    }
  ]
}))
formData.append('page1.jpg', fs.createReadStream('/path/to/page1.jpg'))

;(async () => {
  try {
    const response = await axios.post('https://api.pspdfkit.com/build', formData, {
      headers: formData.getHeaders({
          'Authorization': 'Bearer your_api_key_here'
      }),
      responseType: "stream"
    })

    response.data.pipe(fs.createWriteStream("result.pdf"))
  } catch (e) {
    const errorString = await streamToString(e.response.data)
    console.log(errorString)
  }
})()

function streamToString(stream) {
  const chunks = []
  return new Promise((resolve, reject) => {
    stream.on("data", (chunk) => chunks.push(Buffer.from(chunk)))
    stream.on("error", (err) => reject(err))
    stream.on("end", () => resolve(Buffer.concat(chunks).toString("utf8")))
  })
}
import requests
import json

instructions = {
  'parts': [
    {
      'file': 'page1.jpg'
    }
  ]
}

response = requests.request(
  'POST',
  'https://api.pspdfkit.com/build',
  headers = {
    'Authorization': 'Bearer your_api_key_here'
  },
  files = {
    'page1.jpg': open('/path/to/page1.jpg', 'rb')
  },
  data = {
    'instructions': json.dumps(instructions)
  },
  stream = True
)

if response.ok:
  with open('result.pdf', 'wb') as fd:
    for chunk in response.iter_content(chunk_size=8096):
      fd.write(chunk)
else:
  print(response.text)
  exit()
<?php

$FileHandle = fopen('result.pdf', 'w+');

$curl = curl_init();

$instructions = '{
  "parts": [
    {
      "file": "page1.jpg"
    }
  ]
}';

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.pspdfkit.com/build',
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_POSTFIELDS => array(
    'instructions' => $instructions,
    'page1.jpg' => new CURLFILE('/path/to/page1.jpg')
  ),
  CURLOPT_HTTPHEADER => array(
    'Authorization: Bearer your_api_key_here'
  ),
  CURLOPT_FILE => $FileHandle,
));

$response = curl_exec($curl);

curl_close($curl);

fclose($FileHandle);

Combining Multiple Images into a PDF

While converting a single image to a PDF is quite useful, often you’ll have a folder of images — for example, of a scanned document — that you want to combine into a single PDF.

Pass in multiple images — one for each page in your request — and PSPDFKit API will merge all of them into a single PDF.

Add more files in the same folder as your code and run the updated code. You can duplicate and rename your existing file, or you can add some other images.

Code to convert multiple images to PDF:

curl -X POST https://api.pspdfkit.com/build \
  -H "Authorization: Bearer your_api_key_here" \
  -o result.pdf \
  --fail \
  -F page1.jpg=@/path/to/page1.jpg \
  -F page2.jpg=@/path/to/page2.jpg \
  -F page3.jpg=@/path/to/page3.jpg \
  -F page4.jpg=@/path/to/page4.jpg \
  -F instructions='{
      "parts": [
        {
          "file": "page1.jpg"
        },
        {
          "file": "page2.jpg"
        },
        {
          "file": "page3.jpg"
        },
        {
          "file": "page4.jpg"
        }
      ]
    }'
curl -X POST https://api.pspdfkit.com/build ^
  -H "Authorization: Bearer your_api_key_here" ^
  -o result.pdf ^
  --fail ^
  -F page1.jpg=@/path/to/page1.jpg ^
  -F page2.jpg=@/path/to/page2.jpg ^
  -F page3.jpg=@/path/to/page3.jpg ^
  -F page4.jpg=@/path/to/page4.jpg ^
  -F instructions="{\"parts\": [{\"file\": \"page1.jpg\"}, {\"file\": \"page2.jpg\"}, {\"file\": \"page3.jpg\"}, {\"file\": \"page4.jpg\"}]}"
package com.example.pspdfkit;

import java.io.File;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;

import org.json.JSONArray;
import org.json.JSONObject;

import okhttp3.MediaType;
import okhttp3.MultipartBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public final class PspdfkitApiExample {
  public static void main(final String[] args) throws IOException {
    final RequestBody body = new MultipartBody.Builder()
      .setType(MultipartBody.FORM)
      .addFormDataPart(
        "page1.jpg",
        "/path/to/page1.jpg",
        RequestBody.create(
          new File("/path/to/page1.jpg"),
          MediaType.parse("image/jpeg")
        )
      )
      .addFormDataPart(
        "page2.jpg",
        "/path/to/page2.jpg",
        RequestBody.create(
          new File("/path/to/page2.jpg"),
          MediaType.parse("image/jpeg")
        )
      )
      .addFormDataPart(
        "page3.jpg",
        "/path/to/page3.jpg",
        RequestBody.create(
          new File("/path/to/page3.jpg"),
          MediaType.parse("image/jpeg")
        )
      )
      .addFormDataPart(
        "page4.jpg",
        "/path/to/page4.jpg",
        RequestBody.create(
          new File("/path/to/page4.jpg"),
          MediaType.parse("image/jpeg")
        )
      )
      .addFormDataPart(
        "instructions",
        new JSONObject()
          .put("parts", new JSONArray()
            .put(new JSONObject()
              .put("file", "page1.jpg")
            )
            .put(new JSONObject()
              .put("file", "page2.jpg")
            )
            .put(new JSONObject()
              .put("file", "page3.jpg")
            )
            .put(new JSONObject()
              .put("file", "page4.jpg")
            )
          ).toString()
      )
      .build();

    final Request request = new Request.Builder()
      .url("https://api.pspdfkit.com/build")
      .method("POST", body)
      .addHeader("Authorization", "Bearer your_api_key_here")
      .build();

    final OkHttpClient client = new OkHttpClient()
      .newBuilder()
      .build();

    final Response response = client.newCall(request).execute();

    if (response.isSuccessful()) {
      Files.copy(
        response.body().byteStream(),
        FileSystems.getDefault().getPath("result.pdf"),
        StandardCopyOption.REPLACE_EXISTING
      );
    } else {
      // Handle the error
      throw new IOException(response.body().string());
    }
  }
}
using System;
using System.IO;
using System.Net;
using RestSharp;

namespace PspdfkitApiDemo
{
  class Program
  {
    static void Main(string[] args)
    {
      var client = new RestClient("https://api.pspdfkit.com/build");

      var request = new RestRequest(Method.POST)
        .AddHeader("Authorization", "Bearer your_api_key_here")
        .AddFile("page1.jpg", "/path/to/page1.jpg")
        .AddFile("page2.jpg", "/path/to/page2.jpg")
        .AddFile("page3.jpg", "/path/to/page3.jpg")
        .AddFile("page4.jpg", "/path/to/page4.jpg")
        .AddParameter("instructions", new JsonObject
        {
          ["parts"] = new JsonArray
          {
            new JsonObject
            {
              ["file"] = "page1.jpg"
            },
            new JsonObject
            {
              ["file"] = "page2.jpg"
            },
            new JsonObject
            {
              ["file"] = "page3.jpg"
            },
            new JsonObject
            {
              ["file"] = "page4.jpg"
            }
          }
        }.ToString());

      request.AdvancedResponseWriter = (responseStream, response) =>
      {
        if (response.StatusCode == HttpStatusCode.OK)
        {
          using (responseStream)
          {
            using var outputFileWriter = File.OpenWrite("result.pdf");
            responseStream.CopyTo(outputFileWriter);
          }
        }
        else
        {
          var responseStreamReader = new StreamReader(responseStream);
          Console.Write(responseStreamReader.ReadToEnd());
        }
      };

      client.Execute(request);
    }
  }
}
// This code requires Node.js. Do not run this code directly in a web browser.

const axios = require('axios')
const FormData = require('form-data')
const fs = require('fs')

const formData = new FormData()
formData.append('instructions', JSON.stringify({
  parts: [
    {
      file: "page1.jpg"
    },
    {
      file: "page2.jpg"
    },
    {
      file: "page3.jpg"
    },
    {
      file: "page4.jpg"
    }
  ]
}))
formData.append('page1.jpg', fs.createReadStream('/path/to/page1.jpg'))
formData.append('page2.jpg', fs.createReadStream('/path/to/page2.jpg'))
formData.append('page3.jpg', fs.createReadStream('/path/to/page3.jpg'))
formData.append('page4.jpg', fs.createReadStream('/path/to/page4.jpg'))

;(async () => {
  try {
    const response = await axios.post('https://api.pspdfkit.com/build', formData, {
      headers: formData.getHeaders({
          'Authorization': 'Bearer your_api_key_here'
      }),
      responseType: "stream"
    })

    response.data.pipe(fs.createWriteStream("result.pdf"))
  } catch (e) {
    const errorString = await streamToString(e.response.data)
    console.log(errorString)
  }
})()

function streamToString(stream) {
  const chunks = []
  return new Promise((resolve, reject) => {
    stream.on("data", (chunk) => chunks.push(Buffer.from(chunk)))
    stream.on("error", (err) => reject(err))
    stream.on("end", () => resolve(Buffer.concat(chunks).toString("utf8")))
  })
}
import requests
import json

instructions = {
  'parts': [
    {
      'file': 'page1.jpg'
    },
    {
      'file': 'page2.jpg'
    },
    {
      'file': 'page3.jpg'
    },
    {
      'file': 'page4.jpg'
    }
  ]
}

response = requests.request(
  'POST',
  'https://api.pspdfkit.com/build',
  headers = {
    'Authorization': 'Bearer your_api_key_here'
  },
  files = {
    'page1.jpg': open('/path/to/page1.jpg', 'rb'),
    'page2.jpg': open('/path/to/page2.jpg', 'rb'),
    'page3.jpg': open('/path/to/page3.jpg', 'rb'),
    'page4.jpg': open('/path/to/page4.jpg', 'rb')
  },
  data = {
    'instructions': json.dumps(instructions)
  },
  stream = True
)

if response.ok:
  with open('result.pdf', 'wb') as fd:
    for chunk in response.iter_content(chunk_size=8096):
      fd.write(chunk)
else:
  print(response.text)
  exit()
<?php

$FileHandle = fopen('result.pdf', 'w+');

$curl = curl_init();

$instructions = '{
  "parts": [
    {
      "file": "page1.jpg"
    },
    {
      "file": "page2.jpg"
    },
    {
      "file": "page3.jpg"
    },
    {
      "file": "page4.jpg"
    }
  ]
}';

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.pspdfkit.com/build',
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_POSTFIELDS => array(
    'instructions' => $instructions,
    'page1.jpg' => new CURLFILE('/path/to/page1.jpg'),
    'page2.jpg' => new CURLFILE('/path/to/page2.jpg'),
    'page3.jpg' => new CURLFILE('/path/to/page3.jpg'),
    'page4.jpg' => new CURLFILE('/path/to/page4.jpg')
  ),
  CURLOPT_HTTPHEADER => array(
    'Authorization: Bearer your_api_key_here'
  ),
  CURLOPT_FILE => $FileHandle,
));

$response = curl_exec($curl);

curl_close($curl);

fclose($FileHandle);