# DigiDoc4 Client

> DigiDoc4 (144 stars, 4.11.1 Sep 2026) is the Qt desktop client from Estonia's Information System Authority (RIA), shipped as part of the ID-software for Windows 10/11, macOS 14+ and Ubuntu 22.04-26.04. You add files and sign them with an Estonian ID-card in a card reader, Mobile-ID or Smart-ID; it also encrypts files and manages ID-card PIN codes. LGPL-2.1. It is only useful if you hold an Estonian eID, and it has no sending, routing, reminders or templates: each person signs on their own computer.

- Repository: https://github.com/open-eid/DigiDoc4-Client
- Official docs: https://www.id.ee/en/article/you-wish-to-add-a-digital-signature-using-a-computer-5/
- Checked: 2026-10-16

## What it replaces
- DocuSign: Certificate-based digital signatures (PKI) (partial). Certificate signing for Estonian eID holders only; documents are passed around by hand, not routed.

## Facts, with sources

| Question | Status | Answer | Source | Checked |
|---|---|---|---|---|
| Runs on my machine? | Confirmed | Yes, desktop app | https://www.id.ee/en/article/install-id-software/ | 2026-10-16 |
| Code licence | Partial | LGPL-2.1 (weak copyleft) | https://github.com/open-eid/DigiDoc4-Client#readme | 2026-10-16 |
| Model weights licence | Confirmed | No separate model weights | https://github.com/open-eid/DigiDoc4-Client#readme | 2026-10-16 |
| Commercial use | Partial | LGPL-2.1 conditions apply; support only for official builds from id.ee | https://github.com/open-eid/DigiDoc4-Client#support | 2026-10-16 |
| Paid services needed? | Partial | Normal personal signing has a free reasonable-use allowance; business/high-volume signing requires timestamp and validity-confirmation service arrangements. Mobile-ID/Smart-ID services also depend on the chosen identity method; see provider terms and pricing | https://www.id.ee/en/article/for-organisations-that-sign-large-quantities-of-documents-using-digidoc4-client/ | 2026-10-16 |
| Hardware | Confirmed | A smart-card reader when signing with an ID-card; none for Mobile-ID or Smart-ID | https://www.id.ee/en/article/you-wish-to-add-a-digital-signature-using-a-computer-5/ | 2026-10-16 |
| Operating systems | Confirmed | Windows 10/11, macOS Sonoma (14) and later, Ubuntu 22.04, 24.04 and 26.04 | https://www.id.ee/en/article/install-id-software/ | 2026-10-16 |
| Setup effort | Confirmed | Easy; official installers for Windows and macOS, install script or APT repository for Ubuntu | https://www.id.ee/en/article/install-id-software/ | 2026-10-16 |

GitHub: 144 stars, 52 forks, last push 2026-10-15, archived: no.
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Source: RepoQuarry (https://repoquarry.dev/projects/digidoc4). Data licence: CC BY 4.0. Quotes are from project documentation and belong to their authors.