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Best Electronic Signature APIs in 2026

Electronic Signature APIs let software add document signing through an API. This list is for people comparing hosted or self-hosted options on a budget, including tools with free plans, trials, or open-source code.

27 apps
Research read 23 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.

8.8 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

Documenso

Free plan APISelf-hostedWeb

Documenso offers signature workflows through web, API, and self-hosted options, with templates and embedding features.

7.4 Free plan · paid from $25/mo (annual) Visit site
4

Dropbox Sign API

Free plan AndroidAPIiPhone+1

Dropbox Sign API combines embedded signature flows, reusable templates, and SDKs for six languages. The free options have request limits, and higher monthly volume requires a sales contact.

7.4 From $75/mo Visit site
5

Blueink eSignature API

Free plan APIWeb

7.3 From $90/mo (annual) · 14-day trial Visit site
6

Document eSign API

Free plan APIWeb

7.2 From $20/mo · 14-day trial Visit site
7

Esig API

Free plan APIWeb

7.1 Free plan Visit site
8

eSignatures.com API

Free plan APIWeb

7.1 From $0.49 Visit site
9

Sertifi by Flywire
by Sertifi by Flywire
Free plan AndroidAPIiPhone+1

Travel companies looking for authorizations can start with the free plan.

7.1 Pricing on request Visit site
10

DocuSeal

Free plan API

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

7.0 Free plan · paid from $20/user/mo Visit site
11

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.

7.0 Free plan · paid from $11/user/mo (annual) · 30-day trial Visit site
12

Signeasy
by Signeasy
Free plan AndroidAPIiPhone+1

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

7.0 Free plan · paid from $10/user/mo · 14-day trial Visit site
13

Signority API
by Signority API
Free plan APISelf-hostedWeb+1

Signority API offers a range of signing workflows, developer environments, and Canadian document hosting.

7.0 Free plan · paid from $12/mo · 14-day trial Visit site
14

Foxit eSign
by Foxit eSign
Free plan API

Choose Foxit eSign if your organization needs API-based signatures with templates, bulk sending, and authentication options.

6.9 Free plan · 14-day trial Visit site
15

Zoho Sign
by Zoho Sign
Free plan AndroidAPIExtension+4

6.9 Free plan · 14-day trial Visit site
16

Namirial Sign
by Namirial Sign
Free plan API

Choose Namirial Sign if your signing workflow needs identity verification, SMS authentication, templates or an audit trail. Look elsewhere if you need a platform other than API.

6.8 Free plan Visit site
17

Sertifi

Free plan APIWeb

Sertifi brings signature requests, payment workflows, and authorizations together for hospitality use cases.

6.8 Pricing on request Visit site
18

SignWell
by SignWell
Free plan API

6.5 Free plan · paid from $10/user/mo (annual) Visit site
19

Adobe Acrobat Sign
by Adobe Acrobat Sign
Free trial APIWeb

Acrobat Sign combines signature workflows with document tools, integrations, and team administration.

6.3 Visit site
20

ctSignature

Free trial APIWeb

6.2 From $10 Visit site
21

Assently API
by Assently API
Paid AndroidAPIiPhone+1

6.1 From €255/mo Visit site
22

Firma.dev

Free trial APIWeb

5.9 From €0.05 Visit site
23

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
24

Scrive API
by Scrive API
Free trial APIWeb

Scrive eSign API is built for organisations that need configurable electronic signing inside existing systems.

5.7 Pricing on request · 30-day trial Visit site
25

Signaturit
by Signaturit
Free trial APIWeb

Signaturit combines several signature types with identity verification and API options. Its plan descriptions and transaction limits are useful to weigh against a team’s expected signing volume.

5.7 From €10/user/mo · 14-day trial 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-plan terms, trial length, licence rights, and paid starting prices. Before choosing, review platforms, embedded signing, signer authentication, webhooks, templates, signing order, bulk sending, and maximum signers.

Questions

Do these APIs have free plans?

Some entries offer free plans. Check each plan's terms and limits before choosing.

Are free trials available?

Some entries include free trials. Review the duration and conditions before starting.

Can I self-host an electronic signature API?

Some entries support self-hosted deployment. Check the deployment options for the tool you are considering.

Which signing capabilities should I compare?

Compare embedded signing, signer authentication, webhooks, templates, signing order, bulk sending, and maximum signers.

Is open-source code available?

Certain entries publish open-source code. Check the licence and permitted use before adopting a tool.

Questions

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