Sales & CRM·Standings

E-Signature APIs Software

E-signature API software lets a business add electronic signing to its apps; the choice depends on how the API fits existing systems and what signing and pricing limits apply.

Compare platform support, signing methods, webhook events, bulk sending, SDK languages, sandbox access and monthly envelope limits. The board shows a signal score out of 10, plus marks for a public API, open-source code and a free tier.

• 26 platforms
• 16 with a public API on this page
• 16 with a free tier
• Checked 28 Sept 2026

1. #PlatformSignalPlugs inPrice
2. 1
   O

   OpenSignopensignlabs.com

   OpenSign provides cloud and self-hosted electronic document signing for creating, sending, signing, storing and tracking documents.

   8.9 APIOpenFree Free tier · from $9.99/mo
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3. 2
   ZS

   Zoho Signzoho.com

   E-signature software for web, desktop, mobile, browser extensions, and APIs with a free plan.

   7.9 APIOpenFree Free tier · from $10/mo
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4. 3
   DS

   Dropbox Signdropbox.com

   Electronic signing service for web, Android, iOS, and APIs, with a free plan.

   7.8 APIOpenFree Free tier
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5. 4
   S

   Signeasysigneasy.com

   Signeasy lets users sign, send, track, and manage contracts and other documents.

   7.8 APIOpenFree Free tier · from $10/mo
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6. 5
   S

   SignRequestsignrequest.com

   E-signature software with templates, bulk sending, audit trails, API access, and a free plan.

   7.7 APIOpenFree Free tier · from €9/mo
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7. 6
   S

   Skribbleskribble.com

   E-signature app for Android, iOS, web, and API use, with audit logging and a free plan.

   7.7 APIOpenFree Free tier · from €23/mo
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8. 7
   XS

   Xodo Signeversign.com

   E-signature software for Android, iOS, and APIs, with audit trails and a free plan.

   7.6 APIOpenFree Free tier
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9. 8
   B

   BoldSignboldsign.com

   Electronic signing service with an audit trail, free plan, and apps for mobile, APIs, and extensions.

   7.6 APIOpenFree Free tier · from $5/mo
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10. 9
    E

    eSignlyesignly.com
    7.6 APIOpenFree Free tier · from $10/mo
    →
11. 10
    DE

    DocuSign eSignaturedocusign.com

    Electronic signing API with audit trails, a free plan, and paid access from $11 per user monthly.

    7.3 APIOpenFree Free tier · from $11/mo
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12. 11
    S

    SignWellsignwell.com
    6.6 APIOpenFree Free tier · from $10/mo
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13. 12
    D

    DocuSealdocuseal.com
    6.6 APIOpenFree Free tier · from $0.20/mo
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14. 13
    EC

    eSignatures.com APIesignatures.com

    Contract API supporting email, SMS, embedded signing, links, and webhook status updates.

    6.0 APIOpenFree Free tier
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15. 14
    BE

    Blueink eSignature APIdeveloper.blueink.com

    Electronic signing API for sending and tracking documents; plans start at $90 monthly.

    5.9 APIOpenFree Free tier · from $90/mo
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16. 15
    OS

    OneSpan Signonespan.com
    5.9 APIOpenFree From $22/mo
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17. 16
    S

    signNowsignnow.com

    Signing API with reusable templates and audit trails from $8 per user monthly annually.

    5.8 APIOpenFree From $1.50/mo
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18. 17
    S

    Signablesignable.com

    Signing API with templates, bulk sending, audit trails, and plans from £1.60.

    5.8 APIOpenFree From £341/yr
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19. 18
    LA

    Legalesign APIlegalesign.com

    Signing API with bulk sending and web access; plans start at £1.50.

    5.7 APIOpenFree From £10/mo
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20. 19
    FD

    Firma.devfirma.dev

    Firma.dev is an e-signature API for embedding document signing in applications, aimed at developers and SaaS platforms.

    5.5 APIOpenFree From €100/mo
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21. 20
    AP

    Adobe PDF Services APIAdobe

    Cloud PDF API with a free plan for adding document tools to web software.

    5.2 APIOpenFree Free tier
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22. 21
    E

    eSignlabsesignlabs.com
    4.8 APIOpenFree Free tier
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23. 22
    S

    SignatureAPIsignatureapi.com

    Web signing service with API access, signing order choices, and audit trails from $25 monthly.

    4.3 APIOpenFree From $25/mo
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24. 23
    DA

    D4Sign APId4sign.com.br

    Web signing API with sandbox testing, both signing methods, and webhook events.

    4.1 APIOpenFree —
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25. 24
    SE

    Signicat Electronic Signature APIsignicat.com

    Web signing API with sandbox access, both signing methods, and webhook events.

    4.1 APIOpenFree —
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26. 25
    ES

    E-Signesign.co.uk

    Web e-signature API with sandbox, bulk sending, both signing methods, and webhooks.

    4.0 APIOpenFree —
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Places #1, #2, #3, #4, #5 on this board are open to sponsors. Take #1 · Other ways to advertise

How to choose

Which platforms does the API need to support?

Check platform support against the apps and devices where signing will happen. The board compares API, web, Android, iOS, macOS and Windows availability.

Confirm that the platform you need is listed for the product before planning how it will fit into your workflow.

What should I compare in the pricing?

Compare the free plan, starting price and trial terms, where listed. Pricing may be shown per month, per user, per signature, or on request, so check what the quoted amount applies to.

Also review the monthly envelope limit: an envelope is the package of documents sent for signing. Check whether the plan fits your expected volume.

Can I try the API in a sandbox first?

A sandbox is a test environment for checking an API flow without treating it as a live signing process. Compare whether one is available and whether a free plan or trial gives you a way to evaluate the service.

Which signing methods and workflow features matter?

Compare the signing methods offered with the process your users need. The board also compares webhook events, which are automatic notices when something happens, and bulk sending for sending documents to groups.

Which SDK languages should I check?

An SDK is a set of tools for connecting software to an API. Check the listed SDK languages against the languages your team can use, and review documentation depth when assessing how much guidance is available.

Questions

What is an e-signature API?

It is a way to add electronic signing functions to an app or service through an API, a defined way for software to communicate.

How do I compare e-signature API pricing?

Compare the free plan, paid starting price, trial terms and monthly envelope limit. Check what a listed price covers before comparing it with another plan.

What does a sandbox environment do?

A sandbox is a test environment for checking an API workflow without running it as a live signing process.

What are webhook events in an e-signature API?

Webhook events are automatic notices sent when something happens in a signing workflow, such as a document status changing.

What should I check before choosing an e-signature API?

Check platform support, signing methods, bulk sending, webhook events, SDK languages, sandbox access, pricing and monthly envelope limits.

Some top positions on this board can be paid placements, standing where they were sold. The facts on each platform are not for sale. How we rank · Disclosure