E-signature is a small market in open source, but the three leading projects all name DocuSign directly and are actively maintained. Before you rely on any of them for contracts, check that the signature type meets the rules in your country.
1
docuseal docusealco/docuseal
Create, fill and sign PDF forms with a drag-and-drop field builder, plus an API and embeddable signing. AGPL-3.0.
2
documenso documenso/documenso
‘The open source DocuSign alternative’, built with Next.js and a strong focus on signing infrastructure for developers. AGPL-3.0.
3
OpenSign OpenSignLabs/OpenSign
A free e-signature app with templates, multiple signers and audit trails. Check its license file for the exact terms.
How to choose
All three cover the basic DocuSign workflow. DocuSeal is strongest on form-filling and embedding, Documenso on developer APIs, OpenSign on a ready-to-use app.
How we pick: we start from every public GitHub repository with 1,000+ stars, keep the projects that do the job in the title, and read their descriptions and licenses. Stars show community size, not quality, so we also show maintenance status. Nobody paid to be listed.