OpenSign vs pdfFiller
OpenSign
opensignlabs.com
pdfFiller
pdffiller.comSide by side
| Figure | OpenSign | pdfFiller |
|---|---|---|
| Price from | $9.99/mo | $8/mo |
| Free plan | Yes | — |
| Free trial | Yes | — |
| Open source | Yes | — |
| Web | Yes | — |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 5 | 3 |
| Spec score · E-Signature Software | 9.0 (#4) | 6.9 (#59) |
| Spec score · E-signature tools | 8.9 (#10) | 7.2 (#54) |
| API access | Yes | Yes |
| Audit trail | Yes | Yes |
| Bulk sending | Yes | Yes |
| Document templates | Yes | Yes |
| Free plan | Yes | No |
| Signature order | both | both |
Plans
OpenSign
- FreeFree
- Professional$9.99 a month
- Teams$19.99 a month
- FreeFree
- EnterprisePriced on request
In their own words
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.