Formstack Sign vs OpenSign
Formstack Sign
formstack.com
OpenSign
opensignlabs.comSide by side
| Figure | Formstack Sign | OpenSign |
|---|---|---|
| Price from | $250/mo | $9.99/mo |
| Free plan | — | Yes |
| Free trial | — | Yes |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| iOS | Yes | — |
| Android | Yes | — |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 2 | 5 |
| Spec score · E-signature tools | 7.9 (#37) | 8.9 (#10) |
| Spec score · E-Signature Software | 8.1 (#39) | 9.0 (#4) |
| Spec score · Electronic Signature Software | 8.1 (#19) | 9.0 (#3) |
| API access | Yes | Yes |
| Audit trail | Each signed document automatically receives an audit trail that records document activity. | Yes |
| Bulk sending | Yes | Yes |
| Free plan | No | Yes |
| Integrations | Formstack Sign can be paired with Formstack Documents to generate documents and route them for signature; the product also offers an Open API for custom connections. | The Professional plan lists Zapier integration, Dropbox import and custom Gmail or SMTP sending. |
| Security | Listed security features include SSL encryption and password protection. | The API documentation lists TLS-encrypted transport, audit trails, IP logging, and tamper-evident signed PDFs. |
| Templates | Reusable signature templates can apply fields to frequently used documents. | Users can create reusable templates with pre-placed widgets and send them to one or many signers through the API. |
Plans
OpenSign
- FreeFree
- Professional$9.99 a month
- Teams$19.99 a month
- FreeFree
- EnterprisePriced on request
In their own words
Formstack Sign
Formstack Sign 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.