emSigner API vs OpenSign
emSigner API
emsigner.com
OpenSign
opensignlabs.comSide by side
| Figure | emSigner API | OpenSign |
|---|---|---|
| Price from | — | $9.99/mo |
| Free plan | — | Yes |
| Free trial | Yes | Yes |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| iOS | Yes | — |
| Android | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 5 |
| Spec score · Digital Signature API Software | 8.4 (#9) | 9.0 (#2) |
| Integrations | The maker names Salesforce and SAP connectors and describes using outbound REST calls from CRM or ERP systems. | The Professional plan lists Zapier integration, Dropbox import and custom Gmail or SMTP sending. |
| Intended users | The maker describes emSigner as a secure eSignature workflow solution for companies of different sizes and for workflows involving employees, vendors, and customers. | The documentation describes the product as designed for individuals and businesses, from startups to large corporations. |
| Support | The API pricing page lists 24x7 support with a response-time SLA under 12 hours. | The documentation directs users to contact OpenSign support at [email protected] for assistance. |
Plans
emSigner API
- Professional API envelope plan$0.99, paid once
- Essential$1, paid once
- ProfessionalPriced on request
OpenSign
- FreeFree
- Professional$9.99 a month
- Teams$19.99 a month
- FreeFree
- EnterprisePriced on request
In their own words
emSigner API
emSigner API has no write-up on Specifiction yet; its figures are above.
OpenSign
OpenSign is an open-source PDF e-signature solution for signing, storing, and securing documents. Users can create reusable templates with pre-placed widgets and send them through the API to one or many signers. API workflows include self-signing, drafts, signer roles, public template links, and real-time webhook notifications. Templates can be embedded in React, Next.js, HTML, JavaScript, and Angular projects. The documentation lists TLS-encrypted transport, audit trails, IP logging, and tamper-evident signed PDFs; account protection includes two-factor authentication and passkey sign-in. The free plan costs nothing and lists unlimited digital signatures and templates, completion certificates, sequential signing, OpenSign Drive, and email notifications. Its free-plan guide limits invitation emails to 15 per month; bulk sending and public links require a paid plan. Live API tokens require Professional or Teams, though sandbox tokens are available on all plans. OpenSign provides Docker self-hosting instructions for Linux, macOS, and Windows. Some SMTP features are limited to paid plans.