How to Fill PDF Form in Salesforce Apex using

In this step-by-step guide, we’ll briefly see steps on how to fill PDF form in Salesforce Apex using Initially, we’ll go through all the basic steps on salesforce integration. Later we’ll also see the code and demo video. Let’s get started!

  1. Create Remote Site Settings
  2. Create an Apex Class in Salesforce
  3. Add the API Key
  4. Verify the Code
  5. Search the Files
  6. Source Code Files
  7. Demo Video: Fill PDF Form

Step 1: Create Remote Site Settings

Create two remote site settings in the Salesforce Org like below:

Note that the URL here is “”.

Note that the URL here is “”

Step 2: Create an Apex Class in Salesforce

2. Create an apex class in Salesforce like below and paste the code there.
Once you login to the Salesforce org, you will see the screen like below and click on “Developer Console”

Create an apex class. For this, click on “Files” then “New” then “Apex Class”.

Write the class name “FillPDFFormSimplified” and click “Ok”. Now copy the FillPDFFormSimplified code in this file.
Similarly, create a new file with the name “FillPDFFormSimplifiedTest” and copy the code.

Step 3: Add the API Key

In the FillPDFFormSimplified file, please add the key by replacing the ‘******************************************’.

Then please add the Destination file name which you want as a PDF.

Step 4: Verify the Code

To Verify the code, please open the execute Anonymous window and call the method like below.

Then Click on “Execute”.

Step 5: Search the Files

Now, Search Files from the “App Launcher”.

You will see the resulting PDF file there.

Source Code Files:


public class FillPDFFormSimplified{
    // The authentication key (API Key).
    // Get your own by registering at
    String API_KEY = 'ABCDE';
    // Destination File Name
    string DestinationFile = 'result.pdf';
    // Direct URL of source PDF file.
    string SourceFileUrl = '';
    // PDF document password. Leave empty for unprotected documents.
    string Password = '';
    // File name for generated output. Must be a String
    string FileName = 'f1040-form-filled';
    public void fillPDFForm()
            // Create HTTP client instance
            Http http = new Http();
            HttpRequest request = new HttpRequest();
            // Set API Key
            request.setHeader('x-api-key', API_KEY);
            // Values to fill out pdf fields with built-in pdf form filler
            // To fill fields in PDF form, use the following format page;fieldName;value for example: 0;editbox1;text is here. 
            // To fill checkbox, use true, for example: 0;checkbox1;true. 
            // To separate multiple objects, use | separator. 
            // To get the list of all fillable fields in PDF form please use /pdf/info/fields endpoint.
            String fieldString = '1;topmostSubform[0].Page1[0].f1_02[0];John A. Doe|1;topmostSubform[0].Page1[0].FilingStatus[0].c1_01[1];true|1;topmostSubform[0].Page1[0].YourSocial_ReadOrderControl[0].f1_04[0];123456789';
            // If enabled, Runs processing asynchronously. Returns Use JobId that you may use with /job/check to check state of the processing (possible states: working, 
            Boolean async = false;
            // Prepare requests params as JSON
            // See documentation:
            // Create JSON payload
            JSONGenerator gen = JSON.createGenerator(true);
            gen.writeStringField('url', SourceFileUrl);
            gen.writeStringField('name', FileName);
            gen.writeBooleanField('async', async);
            gen.writeStringField('password', password);
            gen.writeBooleanField('encrypt', false);
            gen.writeStringField('fieldsString', fieldString);
            // Convert dictionary of params to JSON
            String jsonPayload = gen.getAsString();
            // URL of 'PDF Edit' endpoint
            string url = '';
            request.setHeader('Content-Type', 'application/json;charset=UTF-8');
            // Execute request
            HttpResponse response =  http.send(request);                
            // Parse JSON response
            Map<String, Object> json = (Map<String, Object>)JSON.deserializeUntyped(response.getBody());
            if(response.getStatusCode() == 200) 
                if ((Boolean)json.get('error') == false)
                    // Get URL of generated PDF file
                    String resultFileUrl =(String)json.get('url');
                    // Download generated PDF file
                    downloadFile(resultFileUrl, DestinationFile);
                    System.debug('Generated PDF file saved as \'{0}\' file.'+ DestinationFile);
                System.debug('Error Response ' + response.getBody());
                System.Debug(' Status ' + response.getStatus());
                System.Debug(' Status Code' + response.getStatusCode());
                System.Debug(' Response String' + response.toString());
        catch (Exception ex)
            String errorBody = 'Message: ' + ex.getMessage() + ' -- Cause: ' + ex.getCause() + ' -- Stacktrace: ' + ex.getStackTraceString();
    private static void downloadFile(String extFileUrl, String DestinationFile)
        Http h = new Http(); 
        HttpRequest req = new HttpRequest(); 
        extFileUrl = extFileUrl.replace(' ', '%20'); 
        req.setHeader('Content-Type', 'application/pdf');
        //Now Send HTTP Request
        HttpResponse res  = h.send(req); 
        if(res.getStatusCode() == 200) 
            blob fileContent = res.getBodyAsBlob();
            ContentVersion conVer = new ContentVersion();
            conVer.ContentLocation = 'S'; // to use S specify this document is in Salesforce, to use E for external files
            conVer.PathOnClient = DestinationFile + '.pdf'; // The files name, extension is very important here which will help the file in preview.
            conVer.Title = DestinationFile; // Display name of the files
            conVer.VersionData = fileContent;
            insert conVer;
            System.debug('Error Response ' + res.getBody());
            System.Debug(' Status ' + res.getStatus());
            System.Debug(' Status Code' + res.getStatusCode());
            System.Debug(' Response String' + res.toString());


public class FillPDFFormSimplifiedTest
    private  testmethod static void testfillPDFForm()
        Test.setMock(HttpCalloutMock.class, new FillPDFFormSimplifiedTest.DocumentCreationMock());
        (new FillPDFFormSimplified()).fillPDFForm();
        List cv = [select Id, VersionData from ContentVersion];
        System.assertEquals(1, cv.size());
        String strt1 = cv[0].VersionData.toString();
        System.assert(strt1.contains('John A. Doe'));

    private  testmethod static void testfillPDFFormException()
        (new FillPDFFormSimplified()).fillPDFForm();
        List cv = [select Id from ContentVersion];
        System.assertEquals(0, cv.size());

    public class DocumentCreationMock implements HttpCalloutMock {
        public HTTPResponse respond(HTTPRequest req) {
            HttpResponse res = new HttpResponse();
            String testBody = '{"hash":"John A. Doe","url":";x-amz-security-token&X-Amz-Signature=95287bf3c007fed4c2c5aeea1ce75c846cc6c68b22aaf35175ebe41a105f54e1","pageCount":1,"error":false,"status":200,"name":"newDocument","remainingCredits":9913694,"credits":3}';
            res.setHeader('Content-Type', 'application/json');
            return res;

Fill PDF Form – Demo Video