HedgeDoc

What Is HedgeDoc?

Most collaborative document tools extract a high price for real-time editing: your data lives on someone else's server, under a usage agreement you did not fully negotiate, in a jurisdiction that may not be your own. For engineering teams, academic researchers, and privacy-conscious organisations, that trade-off has never sat comfortably.

HedgeDoc solves this problem directly. It is an open-source, self-hosted collaborative markdown editor that runs entirely on infrastructure you control. Multiple users can edit the same document simultaneously, see each other's cursors, and watch the rendered output update in real time — all without a single byte of content leaving your network.

Originally known as CodiMD (the community fork of HackMD CE), the project was renamed HedgeDoc in 2020 and is maintained by a distributed team with roots in Germany. The software is licenced under AGPL-3.0. There is no commercial hosting option, no SaaS tier, and no enterprise sales contact: you deploy it yourself, or you do not use it. That constraint is also the product's core value proposition.

HedgeDoc targets technical teams who are comfortable with Docker and prefer markdown over rich-text editors. Typical users include developer documentation teams, research groups, open-source project contributors, and IT departments running internal knowledge-sharing tools. The project's community is active, the documentation is thorough, and a major architectural rewrite (HedgeDoc 2.0) has been in progress for several years, bringing improved performance and extensibility.

Key Features

Real-Time Collaborative Editing

HedgeDoc's editor shows every participant's cursor position and edits as they happen, with no noticeable lag on a well-provisioned server. Changes synchronise across all open browser sessions instantly. The interface splits the screen between the markdown source on the left and the rendered HTML preview on the right, though users can switch to editor-only or preview-only modes depending on their workflow.

Permission controls are per-note. As the note owner, you configure whether guests can view it, whether logged-in users can edit it, or whether it is private. This granular access control makes HedgeDoc workable for both internal collaboration and controlled external sharing — sharing a public link to a meeting agenda, for example, without granting write access to anonymous visitors.

Diagram and Equation Rendering

HedgeDoc renders Mermaid and PlantUML diagrams inline within documents. For software teams, this means architecture diagrams, entity relationship models, and flowcharts live inside the same document as the prose describing them — no exporting to a separate tool and re-importing screenshots. MathJax support renders LaTeX equations, making HedgeDoc suitable for scientific and academic collaboration where mathematical notation is routine.

These capabilities set HedgeDoc apart from simpler markdown editors. A tool like Notion requires separate diagram integrations with their own pricing and privacy considerations. In HedgeDoc, diagram rendering is core functionality, running entirely within your self-hosted instance.

Presentation Mode

HedgeDoc converts markdown documents into reveal.js slide presentations with a single keyboard shortcut. Sections separated by horizontal rules or heading levels become individual slides. This is particularly useful for technical presentations where the speaker wants to maintain a single source of truth — the same markdown file serves as both the collaborative draft document and the final presentation.

For teams that give regular technical talks, demos, or internal training sessions, this eliminates a common workflow step: drafting in a document, then manually recreating content in presentation software.

Enterprise Authentication

HedgeDoc supports a range of enterprise authentication methods out of the box. LDAP integration allows organisations to use their existing directory service for user provisioning and access control. SAML support — tested with OneLogin and Okta — enables SSO for organisations standardised on those identity providers. OAuth2 with Keycloak, Authelia (OpenID Connect), GitHub, and GitLab are all supported and documented in the official configuration guide.

For IT departments deploying internal collaboration tools, this authentication flexibility removes the need for separate user management. Employees log in with their existing corporate credentials. Offboarding is automatic through the directory service rather than requiring manual account deletion in each tool.

Storage Backends

By default, HedgeDoc stores uploaded images and files in the local filesystem. For production deployments, the platform supports MinIO and any S3-compatible object storage. This allows organisations to store media attachments in their existing storage infrastructure — on-premise MinIO clusters, EU-region S3 buckets, or any compatible provider.

Pricing

HedgeDoc is free. There are no pricing tiers, no usage limits, and no commercial licence to purchase. The AGPL-3.0 licence permits unlimited commercial use, with the requirement that modifications to the HedgeDoc codebase itself are also released under the same licence.

Deployment costs are purely infrastructure: a modest server running Node.js and PostgreSQL (or SQLite for smaller deployments) handles most team sizes comfortably. A €10-20/month VPS is sufficient for teams of 10-50 users with moderate document activity. Larger deployments benefit from dedicated database instances and object storage, but these remain infrastructure choices rather than platform licensing costs.

The only meaningful cost consideration is operational: someone on your team needs to manage the server, apply updates, and handle backups. For teams comfortable with Docker Compose, this is a matter of hours per year, not a dedicated role.

EU Compliance & Privacy

HedgeDoc's compliance story is simple and structurally sound: when self-hosted, all data stays on your infrastructure. There is no SaaS provider, no third-party data processing agreement to negotiate, and no terms of service governing what happens to your documents. GDPR compliance is a function of your own hosting decisions and data handling policies, not a contractual arrangement with an external vendor.

The AGPL-3.0 licence means the complete source code is publicly auditable. Any organisation's security team can review the codebase for vulnerabilities, data handling practices, and authentication logic without requesting access from a vendor. This level of transparency is impossible with proprietary collaboration tools.

HedgeDoc deployments can run on air-gapped internal networks with no external internet connectivity, making them suitable for environments where regulatory requirements prohibit SaaS document tools — defence contractors, government departments, healthcare organisations handling sensitive patient data.

There are no telemetry calls, analytics pings, or external resource loads in the self-hosted build. What you deploy is what runs.

Who It's Best For

Engineering and DevOps teams who live in markdown and need a shared scratchpad for documentation, architecture decisions, runbooks, and meeting notes — without sending content to a SaaS provider.

Research groups and academic institutions requiring collaborative editing with diagram and equation support, and data sovereignty guarantees that cloud-based tools cannot offer.

Organisations in regulated sectors — healthcare, finance, government — that cannot use SaaS document tools due to data residency or audit requirements. Self-hosted HedgeDoc satisfies most internal document collaboration use cases within those constraints.

IT departments seeking internal tooling with enterprise SSO. HedgeDoc's LDAP and SAML support integrates cleanly with existing identity infrastructure.

HedgeDoc is not the right choice for teams that need rich-text formatting, a document hierarchy, page templates, databases, or project management features. Notion, Confluence, or Outline serve those requirements better.

The Verdict

HedgeDoc does one thing — real-time collaborative markdown editing — and does it entirely on your terms. For technical teams where markdown is the natural writing format and data sovereignty is a genuine requirement, there is no stronger open-source alternative. The absence of a hosted option limits accessibility for non-technical users, and community-only support means you are responsible for your own incidents. Both are acceptable trade-offs for the control you gain in return.

Frequently Asked Questions

Is HedgeDoc completely free?

Yes. HedgeDoc is open-source under AGPL-3.0 with no pricing tiers or commercial licences. You self-host it on your own infrastructure at zero software cost. There is no SaaS version available.

Is HedgeDoc GDPR compliant?

When self-hosted, HedgeDoc keeps all data on your own servers with no external transmissions. There is no third-party data processor to sign an agreement with. GDPR compliance depends on your own hosting and data handling decisions, not on a vendor's policies.

How does HedgeDoc differ from Notion or Confluence?

HedgeDoc is markdown-only and has no document hierarchy, database views, project management features, or rich-text formatting. It is a collaborative text editor, not a knowledge management system. Teams that need structured wikis or project tools should look at Outline, Confluence, or Notion instead.

Does HedgeDoc support SSO for enterprise teams?

Yes. HedgeDoc supports LDAP, SAML (tested with OneLogin and Okta), OAuth2, Keycloak, and Authelia for OpenID Connect SSO. GitHub and GitLab OAuth are also supported. Users authenticate with existing corporate credentials.

What is HedgeDoc 2.0 and when will it be released?

HedgeDoc 2.0 is a complete architectural rewrite with improved real-time performance, a modern codebase, and better extensibility. It has been in active development for several years. The current HedgeDoc 1.x branch remains stable and actively maintained with security patches and bug fixes.