Short answer: there are only a few open-source data room options, and none of them is a complete virtual data room you can run for free. Papermark is open source (AGPLv3), but its data rooms, Q&A and advanced permissions sit in the commercially licensed ee/ code, and supported self-hosting is part of a quote-only Enterprise plan. Nextcloud (AGPL) and ONLYOFFICE DocSpace (which has a "Virtual Data Room" room type with watermarks) are file platforms you can configure as a basic room. The licence is free; the server, storage, backups, security patches, monitoring and the audit evidence buyers ask for are not. Self-hosting makes sense when you already run this infrastructure or must keep files on your own servers; for one deal, a hosted room is usually cheaper and faster.
Open-source data room options (2026)
| Project | Licence | What it gives you as a data room | What to know |
|---|---|---|---|
| Papermark | AGPLv3, except the ee/ folders (Papermark Commercial License) | Tracked document links with page-by-page analytics in the open part | The ee/ README lists data rooms, Q&A conversations and advanced permissions as Enterprise Edition features and says you may not host your own version of app.papermark.com without a licence. Supported self-hosting is on the Enterprise plan, price on request |
| Nextcloud | AGPL | Shared folders, user and group permissions, share links with passwords and expiry, access control rules | A general file platform, not a deal room: no NDA gate, no time per page. Enterprise subscriptions (audit-ready logging, support) start at 100 users, from €71.29 per user a year (nextcloud.com/pricing, 10 November 2026) |
| ONLYOFFICE DocSpace | AGPL v3 (Community edition, self-hosted) | A "Virtual Data Room" room type (since DocSpace 3.0) with watermarks that can include the user name and date, copy restrictions and file lifetimes | Check ONLYOFFICE's edition comparison for what the Community edition includes; the Community download page names concurrent connections and support as the difference to Enterprise |
Sources (read 7–10 November 2026): github.com/mfts/papermark (README and ee/README.md), papermark.com/pricing, nextcloud.com/pricing, api.onlyoffice.com (DocSpace sample "Create a virtual data room with a watermark"), onlyoffice.com/download-community. More on Papermark's plans and licence: Papermark pricing.
Can you self-host Papermark for free?
You can self-host the AGPLv3 part. According to its repository, Papermark is a Next.js app on Node.js 18.17 or later with PostgreSQL (Prisma), and the example configuration expects outside services: Vercel Blob or S3 for files, Tinybird for analytics, Resend for e-mail and background-job and cache services; it is built around Vercel rather than shipped as one Docker image. The data room features are in the commercially licensed part, so for a self-hosted data room you need the Enterprise licence. For tracked links only, the AGPL part is enough – and so is a free hosted plan from several providers.
What self-hosting a data room really costs
| Cost item | What it involves | Typical effort |
|---|---|---|
| Server and storage | A VM or managed containers, a database, object storage with versioning, a CDN or reverse proxy, TLS certificates | Monthly hosting bill plus storage that grows with every deal |
| Backups and restore tests | Encrypted off-site backups of files and database; a restore you have actually tried | Set-up, then a check every month |
| Security patches | OS, database, the app and its dependencies; AGPL projects release fixes you must apply yourself | Ongoing – an unpatched room with confidential deal files is the worst case |
| E-mail delivery | Invitations and one-time codes must reach buyers' corporate inboxes (SPF, DKIM, DMARC, a sending service) | Set-up plus monitoring of bounces |
| Monitoring and on-call | Someone fixes it when a bidder cannot log in on a Sunday before the bid deadline | A person, not a line item |
| Compliance evidence | Buyers' and investors' security questionnaires ask about encryption, access logs, penetration tests and certifications; a certification covers the environment you run, not the open-source code | Your own policies and audits |
| Missing deal features | NDA before access, a watermark with each viewer's e-mail, page-by-page reading time, per-bidder reports, an archive at closing | Build, configure or do without |
If one engineer spends even a few days setting up and a few hours a month maintaining the room, the cost passes the price of a hosted room for a single deal quickly. Use our data room cost calculator for the hosted side of the comparison.
When self-hosting makes sense
- You already run Nextcloud, ONLYOFFICE or similar for the company, with backups, monitoring and an admin – adding a room is a small step.
- Files may not leave your own servers or a specific country, by law or by contract.
- You need deep customisation or integration and have developers to maintain it.
- You host many rooms all year and the infrastructure cost is spread across them.
When a hosted data room is the better choice
- One deal: a sale, a funding round, a refinancing – weeks or months, not years.
- No in-house admin for a public, internet-facing app holding confidential documents.
- You need NDA before access, per-viewer watermarks and activity reports without building them.
- Buyers expect a familiar, reliable login and a clear audit trail at closing.
HelpRange as the hosted alternative
HelpRange is not open source; it is a hosted data room priced per team, not per user, with unlimited guests. New uploads are encrypted and stored in Frankfurt (EU); older files are in the US. What you get without running a server: NDA before access with a PDF record, a watermark with each viewer's e-mail, download and print blocking, per-guest permissions and access expiry, page-by-page reading time and visit replay, automatic index numbering with XLSX/CSV/PDF export, and freeze and archive at closing (ZIP of the originals, audit report, index and activity log).
Prices: Pro $39 per team a month (up to 3 rooms, no NDA), Max $87 a month (unlimited rooms, NDA, freeze and archive), or the Deal Room Pass at $199 once for 90 days. Try everything in the 3-day trial first. Your whole team, unlimited guests, one price. Or $199 for a single deal. No sales call.
FAQ
Is there an open-source virtual data room?
Partly. Papermark is open source (AGPLv3), but its data room features are in commercially licensed code. Nextcloud and ONLYOFFICE DocSpace are open-source file platforms that can be configured as a basic data room; ONLYOFFICE DocSpace has a dedicated Virtual Data Room room type.
Is Papermark's data room open source?
No. Papermark's repository puts data rooms, Q&A conversations and advanced permissions in the ee/ folders under the Papermark Commercial License, which needs an Enterprise licence for production use.
Is a self-hosted data room free?
The licence can be free; running it is not. You pay for the server, storage and backups, and someone has to patch, monitor and support it, and answer buyers' security questions.
Is a self-hosted data room more secure?
Only if it is run well. You control where the files are, but you also own every patch, backup and access log. A hosted room shifts that work to the provider; check its encryption, storage location and audit trail.
What is the cheapest alternative to self-hosting for one deal?
A one-time hosted room. HelpRange's Deal Room Pass is $199 once for 90 days with unlimited guests, NDA, watermarks and activity reports, with no server to run. Free hosted options are listed in our free virtual data room guide.
Related: free virtual data rooms · Papermark pricing · Papermark alternative · best virtual data room providers · what is a virtual data room.