Online Electronic Signature (E-signature) platforms typically provide a convenient way to send and collect legally binding signatures from clients and remote teams.
But with API, you get the flexibility to develop a documentation process that’s most suited to your business needs.
In this article, we will review some of the software products that deliver such services. With a list of the best API tools for comparison, you can make a better purchase decision.
What is E-signature API and Why Do you Need It
E-signature API, in layman’s terms, is a technology that enables you to implement digital signatures into your app or any other third-party platform. It acts as a connecting gate between two software products, where one essentially agrees to provide another access to its features.
Organizations typically use APIs to extend their system functions and reduce the signing process time. The integrations not only allow them to manage documents directly from their software, but also give them tools to optimize their workflows.
Below, you’ll find the 12 best e-signature apps that offer API service, either as a separate product or an integration. The list contains industry leaders, user-friendly software, and emerging platforms.
SignNow’s API makes it easier to embed the e-signature function into your CRM or your company’s application.
Once you connect it to your system, you can create custom e-signature fields on the page, develop fillable forms, attach payment requests and manage PDF files. You will also be able to add extra text boxes to collect other information and save them as templates for later use.
For smooth transactions, you can send both role-based and freeform invites in bulk and ensure everyone signs the documents on time. Each file you deliver via Sign Now API will be secure, trackable, and mobile-friendly.
- Embeddable e-signature with flexible options.
- Unlimited templates for multiple uses.
- Advanced fields for personalized information.
- Fillable forms to collect additional data.
- White labeling.
- Freeform invites let recipients sign anywhere.
- Bulk sending and reporting.
- Authentication to verify identities.
SignNow API plans start at $84 per month. You also get a sandbox account and a free trial to test the functions.
Singnaturely API integrates e-signature functions with a messaging app or any platform you typically use for document management. It’s designed to simplify the paperwork process by allowing you to create, send, and collect signed documents from one place.
You can perform basic actions via its API, like a bulk invitation and request automation. You can also add a signing field to online PDF documents and get signatures from your website.
The platform delivers a free account for testing and offers a template library to generate quick contracts.
- Integration with your CRM or messaging app.
- Embed signature into online forms.
- Reusable templates.
- Workflow automation.
- Bulk invitations and reminders.
- Custom branding.
- Open authentication.
- Free testing.
Signaturely API plans start from $49. For enterprise solutions, it charges $199 per month.
3. ZOHO Sign
ZOHO Sign delivers API in its enterprise plan. Through it, you can incorporate core functions like signature embedding and file tracking, into your application,
You can create custom templates, update new information in the document anytime, and download signed files as PDFs. You can also use different languages for overseas transactions to optimize the process.
If you encounter any difficulty, you can easily reach out to its customer service for technical support. The platform has a dedicated API team specifically for this purpose.
- Template and embedded signature.
- Document and user management.
- Webhooks, audit trail, and reporting.
- Reminders for recipients.
- Verification via SMS and email.
- Multi-lingual support for international documents.
- File upload and download.
ZOHO Sign charges $0.50 per document. You can buy credits and take a 14-day free trial to test the integrations.
4. Panda Doc
Panda Doc API allows both document generation and e-signatures embedding.
With access to templates and dynamic fields, you can turn your existing PDF into interactive documents and send them to multiple recipients. The templates are visually appealing and deliver versatile text fields to customize documents.
For legal contracts and agreements, Panda Doc API provides embeddable signatures and collaborative tools. Your clients will be able to redline sentences for revision, drop comments to share feedback, and later sign the final drafts via email. You can track each change and stay updated with auto notifications and reminders.
- Document generation.
- Embeddable e-signature accessible via email, app, and mobile
- Template library with 450 layouts.
- Custom fields for auto-filling.
- Bulk invitation to multiple recipients with signing order.
- White labeling.
- Collaboration with track changes option.
Panda Doc charges $2 per signature.
DocuSign offers a set of scalable API products designed to meet different business requirements.
You’ll be able to build fillable forms, send legal documents in batches, add authentication for security and get signatures via multiple mediums.
If you frequently tailor your page content to collect personalized information, you can save time by adding conditional fields in your standard templates. The conditional fields only reveal fillable boxes to those who meet specific conditions.
One other interesting product of DocuSign is the click API. It allows you to embed agreement documents with clickable options for consent into your site.
- Unlimited templates.
- Multiple documents in one envelope.
- All the basic fields to collect the necessary information.
- Signature invites via email, SMS, and app.
- The signee can open secure documents on the mobile.
- White labeling and multilingual support.
- Reporting and analysis.
- Sandbox for testing.
DocuSign prices begin from $75. You can get started for free and explore all products before upgrading your account.
Eversign lets you send unlimited documents from your app and automate up to 500 files each month.
You can set up signature fields in a sequence for a smooth experience, and offer recipients the flexibility to type their names as a signature. Both generated and drawn signatures via Eversign are acceptable and legally binding.
If you handle documents of multiple companies, you can invite teams to collaborate and assign them some of the work. The app also offers custom branding to keep files separate, and 2-factor authentication to protect confidential information.
- Drawn and typed e-signature options.
- In-person and remote signing.
- Manual and automated document sending.
- Up to 25 templates with pre-defined recipients.
- SMS credits for authentication messages.
- Integration with Dropbox and Gmail.
- Team collaboration.
- Custom branding.
Eversign API prices range between $50 and $400.
Signable provides free API access in its regular plans.
With its API integration, you can develop fillable forms and embed them as widgets into your website to make the signing process quick and easy. Its other functions include template creation, custom branding, and envelope management.
Since Signable API is available in all its plans, you can access it regardless of the package you choose. You can also connect it with your CRM to streamline your workflows.
Overall, it’s the best tool for those who need both user-friendly and custom e-signature solutions for their business.
- Send and manage envelopes.
- E-signature fields and fillable forms.
- Sharable templates.
- Integration with Website and CRM.
- White Labeling.
- Team invitation.
Signable premium plans cost a minimum of £25 per month. If your transaction volume is high, you can request more envelopes.
DropBox Sign offers a light and secure API for e-signatures.
You can develop embeddable templates, send signing requests to up to 250 people at once, and time-stamp transactions to track signing status. The services also include multiple e-signature boxes, conditional fields, and multi-lingual support.
For data security, you can mask fields and add SMS authentication to ensure no sensitive information gets leaked to an unauthorized party. You’ll have the option to make tamper-proof documents and try out your workflow with the test mode.
- Embeddable and sharable templates.
- User-friendly editor and bulk invitation.
- Drawn, typed, and uploaded e-signatures.
- Basic and advanced fields.
- Audit trail to see document status.
- Mobile-friendly files and data security.
- 22 different language support.
- White labeling.
Dropbox Sign API prices start from $100. You can try it for free before purchasing the monthly subscriptions.
If you prefer a basic e-signature integration, try DigiSigner. It enables you to attach legal agreements to your website or send document links via email.
You can convert uploaded files into templates, add your logo to the pages, and include both drawn and typed signing options to make the process easy.
On each signing request, you will receive an alert notifying you of the status change anytime someone signs your documents.
For tutorials, you can check out its documentation. The website shares user-friendly guides with clear explanations to help you implement e-signatures.
- Embeddable documents for the website.
- Four types of e-signatures and text tags.
- Email invitation for e-signing.
- Safe transactions.
- Custom branding.
- Flexible payment method.
DigiSigner charges $.0.50 for each document. You can create a free account and test it.
10. Signing Hub
Signing Hub API, like DigiSigner’s, is also best for two functions. One is to embed a legally binding signature field into any document and send them securely via email. Two, to create fillable contracts and add them to your website for signatures.
It also has great security features. It tracks each transaction and automatically locks the fields once the recipients send the signed documents to avoid tampering. Another good function is an auto File Processor. It puts organization seals — like you typically see on invoices — in bulk.
The best thing about Signing Hub is its workflow flexibility. You can develop separate documentation processes for website visitors and external clients, or incorporate both in a single workflow.
- Legally binding e-signatures on any document.
- Embeddable contracts.
- Bulk signing.
- Secure transactions.
- Flexible workflows and mobile support.
- Email authentication and notification.
- Access to all platform features.
Signing Hub shares prices on request. Contact sales for its Signature plan.
SignEasy API is built for both small businesses and established organizations. It enables you to send from 40 to 1800 envelopes per year.
You can connect it with any website, third-party CRM, and custom app. It places no limit on the number of templates you create and provides merge fields to send pre-filled documents.
With webhooks and audit trail, you can stay updated on every activity and download pages once they’re signed.
Other functions you can do with Sign Easy API are custom branding, document management, bulk invitation, and sub-account creation.
- Embeddable signing.
- Integration with websites and CRM like HubSpot and Salesforce.
- Unlimited templates for reusable documents.
- Merge fields to deliver pre-filled pages.
- Authentication for safe transactions.
- Bulk sending and signing.
- Custom branding.
- Test mode.
SignEasy charges a minimum of $299 per year. You can send the first 40 envelopes for free.
BoldSign offers attractive API plans for small businesses.
Its starter package costs around $72 per month and contains 40 envelopes, unlimited templates, complex workflows, and authentication.
For signature collection, you can attach signing fields to legal pages or connect the software to the company’s platform. Recipients will be able to access and sign documents via your app.
You can further create user accounts for your team, integrate cloud services like Google Drive, and add your branding for personalization.
Every premium package of BoldSign delivers all the above functions.
- E-signature and customizable templates.
- Team collaboration and document management.
- Automated workflows, reminders, and bulk invitations.
- Authentication and audit trail for security.
- Basic to advanced fields.
- In-person signing.
- Sandbox for testing.
- White labeling.
- Dedicated account manager.
BoldSign API plans range between $72 and $288. The largest package delivers up to 250 envelopes per month.
Every application I have listed above comes with extensive documentation and guides to show you what functions you can and can’t perform with API.
But I still recommend taking trials to test them out and get a better idea yourself.
Create a free developer account today and start experimenting with the tools. Good luck!