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Best E-Signature APIs Software in 2026

E-signature APIs let software send documents for electronic signing and connect signing workflows to other apps. This list is for people choosing an API on a budget.

26 apps
Research read 28 Sept 2026
How the order is worked out

1

OpenSign

Free plan Open source APILinuxMac+3

Choose OpenSign if you need a free PDF signing plan, reusable templates, or self-hosting options.

8.9 Free plan Visit site
2

BoldSign
by BoldSign
Free plan AndroidAPIExtension+1

BoldSign combines contract signing, templates, and audit trails with mobile and API options. Review the plan limits and billing display to find the right fit.

7.6 Free plan · paid from $5/user/mo (annual) · 30-day trial Visit site
3

Dropbox Sign
by Dropbox Sign
Free plan AndroidAPIiPhone+1

Choose Dropbox Sign if you need legally binding online signatures with reusable templates, request tracking, or embedded signing.

7.5 Free plan · paid from $10.05/mo (annual) · 30-day trial Visit site
4

Blueink eSignature API

Free plan APIWeb

7.4 From $90/mo (annual) · 14-day trial Visit site
5

Adobe PDF Services API
by Adobe
Free plan Web

Adobe PDF Services API covers document creation, conversion, page operations, and template-based generation.

7.3 Free plan Visit site
6

eSignatures.com API

Free plan APIWeb

7.2 From $0.49 Visit site
7

eSignly
by eSignly
Free plan AndroidAPIiPhone

eSignly offers a limited free tier alongside paid plans with team workflow features. Its listed paid prices are annual-billing rates, and the free plan limits monthly signing requests.

7.2 Free plan · paid from $10/user/mo (annual) · 30-day trial Visit site
8

Signeasy
by Signeasy
Free plan AndroidAPIiPhone+1

Signeasy combines document signing with a searchable contract repository, integrations, and an API.

7.2 Free plan · paid from $10/user/mo · 14-day trial Visit site
9

DocuSeal

Free plan API

DocuSeal offers several routes for document signing, from a limited free Basic tier to open-source and paid options.

7.1 Free plan · paid from $20/user/mo Visit site
10

DocuSign eSignature
by DocuSign eSignature
Free plan API

DocuSign eSignature combines agreement workflows with signing, audit trails, and integrations. Compare the envelope limits and annual per-user prices with your expected volume before choosing a plan.

7.1 Free plan · paid from $11/user/mo (annual) · 30-day trial Visit site
11

SignRequest

Free plan AndroidAPIiPhone+1

SignRequest covers document preparation, signature routing, and status tracking, with a free tier and reusable templates.

7.1 Free plan · paid from €9/user/mo · 14-day trial Visit site
12

Skribble
by Skribble
Free plan AndroidAPIiPhone+1

Choose Skribble if you need online signatures with signing workflows, audit records or connections to listed business tools.

7.0 Free plan · paid from €23/user/mo · 14-day trial Visit site
13

Zoho Sign
by Zoho Sign
Free plan AndroidAPIExtension+4

6.9 Free plan · 14-day trial Visit site
14

Xodo Sign
by Xodo Sign
Free plan AndroidAPIiPhone

Xodo Sign combines e-signing, document editing, audit trails and team controls, with mobile apps and API workflows.

6.8 Free plan · paid from $3/user/mo (annual) · 7-day trial Visit site
15

SignWell
by SignWell
Free plan API

6.6 Free plan · paid from $10/user/mo (annual) Visit site
16

eSignlabs

Free plan Web

5.9 Free plan · paid from $25/mo Visit site
17

Firma.dev

Free trial APIWeb

5.9 From €0.05 Visit site
18

Legalesign API
by Legalesign API
Free trial APIWeb

Legalesign API combines document workflows with embedding, integrations, and live event reporting. Its approval requirement and mobile-form limitation are important considerations for implementation.

5.9 From £1.50 · 14-day trial Visit site
19

OneSpan Sign
by OneSpan Sign
Paid API

OneSpan Sign combines electronic signing with identity verification and in-house remote notarization.

5.2 From $22/user/mo (annual) · 30-day trial Visit site
20

Signable
by Signable
Paid API

Signable offers API-focused electronic signing with several workflow and authentication features.

5.2 From £1.60 · 14-day trial Visit site
21

signNow
by signNow
Paid API

signNow offers tiered electronic-signature plans with clearly listed workflow and authentication features. Compare the annual prices, document volume, and required controls before choosing a plan.

5.0 From $8/user/mo (annual) · 7-day trial Visit site
22

D4Sign API

Paid Web

4.7 Visit site
23

E-Sign

Paid Web

4.4 Pricing on request · 14-day trial Visit site
24

SignatureAPI

Paid Web

SignatureAPI covers core electronic-signature controls and developer access through a straightforward paid plan.

4.3 From $25/mo Visit site
25

Signicat Electronic Signature API

Paid Web

4.2 Pricing on request Visit site

#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price

Compare free plans, trials, and paid starting prices, then check licence terms if you need open-source code. Review sandbox access, signing methods, envelopes, webhooks, bulk sending, SDK languages, and supported platforms before choosing.

Questions

Are free plans available for e-signature APIs?

Yes. A free plan is offered by items in this category. Check its usage limits and included features before relying on it.

Do these APIs offer free trials?

Yes. A free trial is offered by items in this category. Trial length and terms vary, so check the provider's pricing details.

Can I find open-source e-signature API code?

Yes. Open-source code is offered by items in this category. Review the licence before modifying or distributing the code.

What pricing models should I compare?

Compare subscription and usage-based pricing. Listed starting points include $20/user/month, $25/month, $90/month with annual billing, $0.49, and €0.05.

Which platforms do these tools support?

Platforms represented in this category include API, web, Android, iOS, macOS, and Windows. Check the platform listing for the tool you plan to use.

Questions

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