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5.4#27 in digital signature api softwareFrom £30 a monthWeb
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It suits organisations that need online signing with identity checks, workflow status connections and retrievable signed files. Teams can choose one-off document packs or committed monthly volumes.
OpenSign may suit individuals and businesses that need PDF signing, reusable templates, or API-based signing workflows. It also offers self-hosting instructions for those who want to run it on Linux, macOS, or Windows.