LibreSign: open electronic signatures serving data sovereignty

In a world where contracts and documents are increasingly signed remotely, electronic signature solutions such as DocuSign or Adobe Sign have become standard. However, these commercial services are generally proprietary, hosted on the vendor's cloud, and often costly. For organizations concerned with data sovereignty – that is, keeping full control over where and how their documents are stored – it is important to find open source and self-hosted alternatives. This is where Nextcloud comes in, a free and self-hostable online collaboration platform widely adopted in both the public and private sectors to replace proprietary cloud services. Nextcloud lets you store and share your files on your own servers, while offering a rich ecosystem of applications. Among these applications is LibreSign, an electronic signature solution that integrates directly with Nextcloud.

Recalling the essentials about Nextcloud, it is a collaboration suite (file sharing, calendar, etc.) comparable to Google Drive/Workspace, but one that stands out for its open source philosophy and its hosting controlled by the user or organization. Many government bodies and businesses have adopted it precisely for these guarantees of confidentiality and regulatory compliance (for example with respect to the GDPR). However, until recently Nextcloud did not natively offer a complete tool for electronically signing PDF documents. Nextcloud users had to either print and scan their handwritten signature (not very secure) or resort to external e-signature services – thereby compromising data sovereignty by sending documents to third-party servers.

LibreSign fills this gap by giving Nextcloud users a way to digitally sign their documents without leaving their environment or relying on an external providerhelp.nextcloud.com. In other words, LibreSign is a natural extension of Nextcloud: providing a free alternative to cloud services, here for electronic signatures, while keeping documents on your servers.

What is LibreSign? How it works and what it does

LibreSign is a web application for electronically signing PDF documents that integrates as an extension (app) into Nextcloudlibresign.coop. Developed since 2020 by the Brazilian cooperative LibreCode, its source code is published under a free licence (AGPL v3) and it is designed to remain open source foreverlibresign.coop. In practical terms, once LibreSign is installed on your Nextcloud instance, you can drop a PDF document into Nextcloud and then send a signature request directly from the interface. Signers receive a link by email or a Nextcloud notification and can sign the document through their web browser, with a high level of security.

Signature request interface in LibreSign (integrated into Nextcloud). The user selects a PDF stored in Nextcloud, then invites one or more signers to sign it electronically.

Under the hood, LibreSign uses public key cryptography (PKI) technologies to digitally sign PDFslibresign.coop. This means that each applied signature is not a mere visual scribble, but an encrypted digital token that guarantees the integrity of the document and the identity of the signer. LibreSign also offers a "hybrid signatures" approach, giving you the choice between:

• Using the user's personal digital certificate (for example a certificate issued by an official certification authority in the signer's name), or
• Automatically generating a digital certificate for the signer if they do not already have onelibresign.cooplibresign.coop.

This flexibility is important: a user who already has a qualified certificate (for example an electronic ID card or a professional certificate) can use it to sign, which gives the signature stronger legal value. Otherwise, LibreSign can create a self-signed certificate to apply the signature: the document will still be protected against any alteration, but since the certificate is internal, it will mainly serve to prove integrity rather than identity verified by a third-party authority.

Among LibreSign's other flagship features, the following are worth noting:

• Advanced security: LibreSign encrypts documents end-to-end during the signing process and supports multi-factor authentication, ensuring that only authorized users can access the documents to be signedlibresign.coop.
• Real-time tracking and reminders: the application lets you track the progress of signatures on a document (who has signed, who has not yet signed) and automatically send reminders to pending signers, which streamlines the processlibresign.coop.
• QR code validation: every signed document can embed a verification QR code. Anyone holding the paper or PDF document can scan this QR code to be redirected to a verification page (on your server) confirming the authenticity of the document and the identity of the signerslibresign.coop. This provides added transparency and trust, particularly if the document leaves the digital environment (printing, external sharing).
• API and integration: LibreSign offers API endpoints that allow it to be integrated with other systems or business applications. Some organizations have, for example, connected LibreSign to their internal management system to automate certain flows (sending contracts via LibreSign directly from a business application)libresign.cooplibresign.coop.

Finally, the LibreSign interface is designed to be relatively easy to use within Nextcloud. Users highlight its intuitive nature, which has improved over successive versionslibresign.coop. In short, LibreSign aims to bring a complete and user-friendly electronic signature solution to Nextcloud, comparable to commercial services, while remaining free and self-controlled.

Legal value: is a digital signature valid before a court?

A crucial question for any electronic signature solution is its legal value. In other words, does a document signed via LibreSign carry the same weight as a document signed by hand, particularly in the event of a dispute or before a judge? The answer depends on the type of electronic signature used, but LibreSign was designed to meet the technical criteria that give digital signatures high legal value.

First, a distinction must be made between the "simple" electronic signature (for example checking a box or pasting an image of your signature) and the advanced or qualified electronic signature. LibreSign favours the advanced signature: each applied signature is accompanied by a digital certificate and a cryptographic hash of the documentlibresign.coop. In concrete terms, when signing a PDF, LibreSign computes a unique fingerprint of the file (hash) and encrypts it with the signer's private key (linked to their digital certificate). The resulting signed PDF contains this information so that any subsequent change to the document will be detectable (the hash would no longer match), and so that you can verify who signed (by validating the signer's certificate)libresign.coop.

These mechanisms comply with digital signature standards and guarantee the authenticity and integrity of the document, two essential conditions for an electronic signature to be admitted as evidencelibresign.coop. For example, in Europe, the eIDAS regulation distinguishes three levels of electronic signature: simple, advanced and qualified. An advanced signature – which links the document to an identity via a certificate and ensures that any change is detectable – is legally recognized and valid, even if it is not "qualified" (that is, issued with a qualified certificate stored on a secure device). LibreSign can produce advanced electronic signatures of this type. Indeed, one user reports that LibreSign "works perfectly with the electronic certificate issued by the Spanish government," which indicates that the application supports official certificates compliant with European standardslibresign.coop. A document signed with such a certificate should therefore have, in Spain (and across the EU), the same value as a document signed via any other eIDAS-compliant platform.

If the signer does not have an official certificate and uses a certificate auto-generated by LibreSign, the legal value will be that of a simple electronic signature, supported nonetheless by technical elements (fingerprint, signing-time log) that can strengthen its credibility. LibreSign does indeed log the timestamp of each signature on the documentlibresign.coop. In the event of a challenge, you could then present the signed PDF document containing the signer's certificate (even an internal one) and prove that it has not been altered since signing. Although such a signature does not have the evidentiary force of a qualified signature, it demonstrates the intent to sign and the integrity of the document, which generally has the value of admissible evidence. Furthermore, since LibreSign is open source, a court expert could audit how it works if necessary to attest to the signing process.

In summary, LibreSign produces technically robust electronic signatures. Used with a recognized certificate, the signature will be fully valid legally (equivalent to a handwritten signature in most jurisdictions)libresign.cooplibresign.coop. Used with an internal certificate, it will still provide a level of security and traceability far superior to a simple scanned signature – the LibreSign website notes, moreover, that a scanned signature guarantees neither identity nor integrity, unlike a cryptographic digital signaturelibresign.coop. In all cases, the solution meets GDPR requirements for data protection and securitylibresign.coop, an important point for regulatory compliance.

Advantages of LibreSign: sovereignty, security and cost

LibreSign offers several key advantages for professionals and organizations looking for an e-signature solution that respects their constraints:

• Sovereignty and full control of data: Because LibreSign runs within your Nextcloud hosted by you, your documents never leave your infrastructure. Unlike a third-party cloud service where contracts would be stored on an external provider's servers, here everything stays with you. This makes it easier to maintain the confidentiality of sensitive data and comply with local data-residency regulations. For example, the French public sector places importance on "digital sovereignty": LibreSign aligns perfectly with this objective by offering a 100% in-house signature solution.
• Free software and auditability: Being open source, LibreSign can be audited by the community or by independent experts. The code can be reviewed to ensure there are no malicious functions or hidden flaws. This transparency increases trust in the tool, particularly for legal uses. Moreover, the entire community benefits from continuous improvements – LibreSign evolves quickly, with frequent updates since its launchapps.nextcloud.comapps.nextcloud.com. Anyone is free to contribute or customize the tool to their specific needslibresign.coop.
• Cost savings: LibreSign is free. Apart from the cost of running your Nextcloud server, you have no licence to pay per user or per signed document, unlike solutions such as DocuSign that operate on a subscription or per-signature billing basis. For small organizations or moderate use, this represents substantial savings on operating costs. Even for larger volumes, LibreSign involves no extra charge, which makes it very competitive financially.
• Seamless integration with your workflows: If your organization already uses Nextcloud to manage its files, adding LibreSign fits naturally into your existing workflows. The documents to be signed can be those already present in your Nextcloud folders, and once signed they stay in the same place (possibly with a signed version of the PDF added). There is no need to download and then re-upload files to a third-party site to get them signed. This integration reduces handling and the risk of error, while keeping the full document history in one place.
• Security and compliance: LibreSign meets the security criteria of digital signatures (as seen above) and helps you comply with legal requirements (traceability, data protection). Being able to host it internally also helps satisfy internal information security policies, by avoiding the need to open up external access. In addition, LibreSign supports two-factor authentication for document access and uses encryption for any transmission, which aligns with security best practiceslibresign.coop.
• Efficiency and productivity: By replacing paper printing, postal mail or even email back-and-forth to sign documents, LibreSign saves valuable time. User testimonials indicate that the tool "speeds up processes and can eliminate the use of paper," making document management smoother and more modernlibresign.coop. Real-time tracking and automatic reminders eliminate tedious manual follow-ups.

In short, LibreSign provides a self-controlled, economical and efficient IT solution for electronic signatures, which makes it an attractive choice for a professional audience that prefers free software.

Limitations and points of attention for LibreSign

Despite its strengths, LibreSign also has a few limitations that are worth addressing honestly:

• Accessibility on mobile: LibreSign's current interface, integrated into Nextcloud, is mostly optimized for a computer screen. Some users found that in 2023 the application "works well on PC but fails on mobile devices" due to a design that was not very responsive (adaptive)help.nextcloud.com. This can be a problem if your signers frequently need to sign from a smartphone or tablet. The good news is that the project keeps improving: other more recent feedback notes that with recent versions (v9+), LibreSign "works on all devices, including mobile"libresign.coop. Nevertheless, the mobile experience remains below that of the best native or responsive web applications. It is recommended to test the interface on different screens beforehand.
• Technical setup: Unlike a turnkey SaaS service, LibreSign requires an installation on your Nextcloud server. On a standard Nextcloud instance (manual install or via Docker), the app deploys relatively easily through the app catalog. However, certain dependencies must be present on the server to use all features. For example, LibreSign requires the JSignPdf tool (a Java library) for PDF signing, as well as Ghostscript and ImageMagick if you want to add visual elements (QR code, text) to signed PDFscommunity.nethserver.orgcommunity.nethserver.org. On some "packaged" Nextcloud installations (such as Nextcloud Snap or restricted environments), installing these additional dependencies may be blocked or non-automatichelp.nextcloud.comhelp.nextcloud.com. You then have to resort to technical workarounds (for example hosting LibreSign as a separate service, or modifying the package configuration). In short, LibreSign requires system/Nextcloud administration skills for an optimal installation. Once configured correctly, keeping the application up to date is done through Nextcloud, but the administrator must ensure that dependencies remain satisfied after updates.
• Limited document formats: Currently, LibreSign only supports PDF files for signing. Office formats (DOCX, ODT, etc.) must therefore first be converted to PDF before signing – a conversion that can fortunately be done easily via Nextcloud if you have, for example, the OnlyOffice/Collabora integration. Conversely, some competing solutions can handle forms or Word documents directly. This is a point to keep in mind: if your workflow involves signing various types of documents, they will need to be converted to PDF beforehand with LibreSign.
• No visual signature: LibreSign ensures legal value through the digital signature internal to the PDF, but does not yet offer a feature to place a visible, stylized handwritten signature on the document. In concrete terms, you cannot (for now) draw your signature or add a signature image at a specific location in the PDF through the interface. The software focuses on the invisible digital signature, optionally adding a validation QR code and footer at the bottom of the document to indicate that it has been signedcommunity.nethserver.org. This is suitable in most professional cases, but if your processes require a visual appearance of an initial or signature at a precise location (for example a signature placed next to the signer's name on the PDF), LibreSign does not do this natively for the momentcommunity.nethserver.org. There is a possibility of adding a signature image with some tinkering (forum mentions indicate that with Ghostscript installed, LibreSign could in theory place an image, but this remains very limited)community.nethserver.orgcommunity.nethserver.org. It is better to assume that LibreSign will give you a signed and verifiable document, but not adorned with a scanned handwritten signature.
• Notifications and external interactions: LibreSign does allow you to invite external signers by email (non-Nextcloud users) to sign a document via a link. However, the experience for these invited signers is basic: they access a signing page without the context of a full platform. There is no sophisticated branding or complex workflow possible (compared to a DocuSign that offers customized flows, fields to fill in within the document, etc.). For advanced needs such as collecting payments during signing, integrating complex forms or managing multiple roles, LibreSign shows its limits – it excels at simple PDF signing but is not a complete transactional document management tool.
• Emerging community and support: Although LibreSign is gaining popularity, it remains less widely used than the market giants. The official documentation is brief, and you sometimes have to turn to the community (Nextcloud forums, the project's GitHub) to find help when there is a problem. The LibreCode developers are active and responsive according to testimonialslibresign.coop, but in the absence of a professional support contract, adopting LibreSign comes with a degree of self-support. For organizations without an IT team, this can be a deterrent – though this should be nuanced, since more and more service companies may offer Nextcloud/LibreSign support given the growing interest.

To sum up, LibreSign is a powerful tool but still young in some respects. For a use oriented toward free software and self-hosting, these technical trade-offs are often acceptable, especially since the project is evolving rapidly. You simply need to be aware of them and assess whether, in your context, these limitations are blocking or manageable.

Comparison: LibreSign versus DocuSeal and market solutions

LibreSign is not the only open source electronic signature solution. Another notable alternative is DocuSeal, often cited as "the best open source alternative to DocuSign"docuseal.comdocuseal.com. Unlike LibreSign, which integrates into Nextcloud, DocuSeal is a standalone electronic signature platform, also open source and able to be self-hosted or used in cloud mode. It is worth comparing LibreSign and DocuSeal, and positioning them against a proprietary player like DocuSign, on a few key aspects:

DocuSeal allows a handwritten signature to be displayed in the PDF, but like LibreSign it mainly generates an internal digital signature. The visual aspect is an optional plus in its interface.

To be verified against the latest DocuSeal versions. A dedicated mobile app has been mentioned on their roadmap.

Comparison analysis: LibreSign and DocuSeal share a common goal – to provide a free alternative to platforms like DocuSign – but take different approaches. LibreSign excels if you are already a Nextcloud user or are considering becoming one: it integrates perfectly into your existing environment and inherits the Nextcloud philosophy (controlled data, simplicity). On the other hand, if you do not use Nextcloud, LibreSign requires installing that entire platform, which can be a deterrent just for electronic signatures. DocuSeal, for its part, is standalone: you can use it independently, either by self-hosting it (Docker, NodeJS server…) or through their cloud service. It is somewhat more mature in terms of user experience (more modern interface, better mobile use) and offers advanced features (API integration, forms, payments) suited to the needs of businesses that want to embed signing in their applications or online processesdocuseal.comdocuseal.com. DocuSeal has even planned a Qualified Electronic Signature (QES) offering compliant with the strictest identification requirements (with an extra charge per signature to pay the certification authority that validates identity)docuseal.comdocuseal.com, which may be of interest to those with contracts requiring this level.

Against a player like DocuSign, the two free solutions stand out mainly through data control and cost. DocuSign is widely recognized and accepted in court without difficulty, but at the price of dependence on third-party infrastructure and fairly high subscription fees (several hundred euros per year for intensive professional use, sometimes much more)eastagile.com. By contrast, DocuSeal and LibreSign offer almost all the features needed for the majority of uses, with no per-document cost. DocuSign retains a few advantages such as native integration with a broader ecosystem (e.g. connectors to Salesforce, Microsoft, etc.) and a hyper-optimized interface with customizable branding, but for many organizations these advantages will not necessarily justify the loss of sovereignty and the additional expense.

Ultimately, the choice depends on the context: for an entity already equipped with Nextcloud wishing to extend its capabilities, LibreSign is a natural choice. For a technical team looking for an open source signature component to embed in its applications, DocuSeal will stand out for its flexibility. And for anyone who absolutely cannot host a solution or needs a qualified certificate without technical effort, a cloud provider like DocuSign will remain an option – but an option paid for dearly, financially and in concessions on data control.

Conclusion: LibreSign, one more step toward digital autonomy

By offering a free, secure and integrated electronic signature solution for Nextcloud, LibreSign fits perfectly into the digital autonomy movement sought by many organizations. This tool helps democratize advanced digital signatures, once reserved for costly solutions, by making them accessible to any Nextcloud user at no additional cost.

Of course, not everything is perfect yet: the application is evolving, with a few rough edges still to polish (notably the mobile experience and the addition of visual signature elements). But the progress made since its creation in 2020 is impressive – the community attests that LibreSign has moved in a short time from a fledgling project to a solution that is "nearly complete, able to replace most commercial signature services"libresign.cooplibresign.coop. The fact that it is free and open source also gives it particular appeal from a preference for free software standpoint: you can adopt it without fear of proprietary lock-in, and even contribute to its improvement.

For a general professional audience, the key takeaway is that yes, there are credible alternatives to DocuSign and the like, and that LibreSign is one of them when you value the sovereignty and local integration of your tools. Coupled with Nextcloud, it offers a complete chain of document management and electronic signature controlled end to end. Its legal value rests on the same technical foundations as the major market players (certificates, fingerprints, timestamping)libresign.coop, a guarantee of reliability in the event of a challenge.

In short, adopting LibreSign means choosing an ethical and pragmatic solution: ethical through its respect for your data and its open model, pragmatic because it meets the very real need to sign documents online quickly and with confidence. And if some features are still missing, it is a safe bet that the strength of the free software community will not be long in closing these gaps. LibreSign thus embodies a successful deep dive into the world of professional free software applications, where each update reinforces the idea that you can combine efficiency and software freedom for the benefit of users.

References 🎓

【25】 LibreSign – Official site (libresign.coop). Overview of LibreSign, the LibreCode cooperative, objectives and user testimonialslibresign.cooplibresign.cooplibresign.cooplibresign.coop

【6】 LibreSign – Flagship features (libresign.coop). Description of the characteristics: advanced security, hybrid signatures, QR code validation, real-time trackinglibresign.cooplibresign.cooplibresign.cooplibresign.coop

【23】 LibreSign – Target audience (libresign.coop). Example of use in education, mention of the legal validity of digital signatureslibresign.cooplibresign.coop

【8】 LibreSign FAQ – Frequently asked questions (libresign.coop). Explanation of the security and legal validity ensured by LibreSign (hash, timestamping, GDPR compliance)libresign.coop

【11】 Nextcloud Forum – Discussion "Electronic signature in Nextcloud". User comment on LibreSign (functional on PC, not suited to mobile, no dependence on an external service)help.nextcloud.com

【12】 Nextcloud Forum – "Problems LibreSign and Nextcloud Snap". Exchanges about the difficulties of installing LibreSign in a Snap environment (certificate errors, dependencies not installed automatically)help.nextcloud.comhelp.nextcloud.com

【27】 NethServer Forum – "LibreSign – Nextcloud". Confirmation of features: electronic signature OK, adding a visible signature requires Ghostscript (visible QR code and footer); no handwritten signature imagecommunity.nethserver.orgcommunity.nethserver.orgcommunity.nethserver.org

【13】 DocuSeal – Official site (docuseal.com). Presentation of DocuSeal as an open source alternative to DocuSign, user testimonials about the UXdocuseal.comdocuseal.com

【15】 DocuSeal – "Qualified Electronic Signature" page. DocuSeal's capabilities regarding eIDAS compliance, qualified signatures, identity verification, data encryptiondocuseal.comdocuseal.com

【17】 DocuSeal – Blog "Top 5 DocuSign Alternatives in 2025". Excerpts about DocuSeal: hosting options (Cloud or On-Premises), free vs paid plan, API/integration strengths, the on-prem advantage for sovereigntydocuseal.comdocuseal.com

【16】 EastAgile Blog – "Choosing the right eSignature Solution". Mention of the high cost of enterprise solutions like DocuSign/Adobe Sign ($300+/month for API…)eastagile.com