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How to make a digital signature to a web application

As the use of electronic signatures becomes widespread, many people are wondering how they can add signing functionality to their apps. Rather than open a separate piece of eSignature software to sign documents, or go through the process of adding signatures to Microsoft Word and PDF documents, they want to quickly type their name or upload an image without having to leave their browser.

This guide is focused on web developers and users that want to add electronic signature capabilities to their apps. There are two reasons they may want to do this. On the one hand, they may want to make documents available to users through their own apps on their websites. On the other, they may wish to access documents via their own CMS like HubSpot or Salesforce.

Whatever the case, the good news is that simple integrations and accessible APIs can be used to easily add signature functionality to all sorts of online apps.

How do electronic signatures work?

Electronic signatures are simply digital marks that are affixed to documents to signify approval. An example of a basic electronic signature would be an image of a scanned signature uploaded to a Microsoft Word document. At the more secure end of the spectrum, “digital” signatures provide high levels of encryption and require special software to make.

Generally speaking, dedicated electronic signature tools are better for adding signatures because they provide an added layer of security available to everybody. Whenever an electronic signature is made through PandaDoc, for example, a certificate is automatically generated which includes the name of the signee along with the date and time of signing. This makes it much easier to verify the signature should the need arise.

Electronic versus digital signatures

Electronic signatures are not the same as digital signatures. As mentioned, electronic signatures are any type of digital mark included in a proposal, quote, contract, or another legally binding document. A digital signature is a highly secure and traceable form of a signature that can only be made using special software.

To use digital signatures, a digital certificate must be acquired from a certificate authority. This certificate is then stored securely by the signee – sometimes on a special USB – and can be attached to documents. A special encrypted version of the document is made during a signing which can be matched to a public version of the certificate. If the match is valid then the digital signature is verified.

Add a digital signature to a web application

There are two options for developers and app users: connect with integration or use an API. In either case, you will need to subscribe to a third-party electronic signature tool. For pre-made or Zapier integrations, you will usually have to enable the integration from the dashboard of the electronic signature software tool and then set it up within the app. For custom-made apps, enabling access to the eSignature software is usually a case of copying-and-pasting some JavaScript code.

Irrespective of the tool you use, the steps below (which are specific to PandaDoc) will give you a rough idea of how the process works.

Connect to a web application with a PandaDoc integration

Integrations enable you to access PandaDoc within your CRM, payments, online storage and so on.

To connect to an app with an integration, simply follow the steps below:

  1. Log into the PandaDoc.
  2. Click on the Settings tab on the options bar on the left of the screen and select Integrations from the menu.
  3. Select the integration you wish to use and click Enable.
  4. Follow the on-screen prompts to set up your integration. You may be guided to connect with your CRM, install a browser plug-in, or connect to your software through Zapier.
  5. Once you’re set up, you can access all of PandaDoc eSignature tools from your app.

Connect to a web application with the PandaDoc API

PandaDoc.js is a JavaScript developer kit that enables PandaDoc tools to be embedded directly into an app. You can upload, send, and receive documents directly from your app and use PandaDoc fully-secure tools to add electronic signatures to documents. It’s a very simple process and only requires a few lines of code to be added to an app’s backend, after which users can access all PandaDoc features from their browser.

Follow the steps below to add PandaDoc electronic signature tools to your app:

  1. Head over the JavaScript SDK page.
  2. Scroll down to the Document Editor Implementation and copy the code highlighted.
  3. Paste the code between HTML <script> tags on the page where you want the PandaDoc editor to be displayed.

It’s also possible to extend this functionality by using the embed.js option if you have programming knowledge.


The simplest way to sign documents securely is to use an electronic signature solution like PandaDoc or DocuSign. The use of full digital signatures is still relatively rare and cumbersome. And simple electronic signatures made on Microsoft Word documents or PDFs lack any extra security and can sometimes be difficult to verify.

Software like PandaDoc offers encryption, certificates, and secure storage of signatures. What’s more, this security framework is applied to every signature made, irrespective of the signee. If you would like to try PandaDoc, why not sign up for a free trial.