Most lists of free enterprise architecture tools are padded with trials, diagram editors and products that stopped being open source years ago. This one is limited to tools with a free edition that does not expire, each fact was checked against the vendor’s own site on 29 September 2026, and every entry says plainly what the tool is and what it is not. Turbo EA leads it because it is the only free tool that gives a whole team a self-hosted EA repository with reporting, process modelling and portfolio management in one install.
Turbo EA is the best free enterprise architecture tool for a team: a self-hosted, multi-user EA repository with more than ten reports, native BPMN 2.0 process modelling, project portfolio management and TOGAF governance artefacts, free for unlimited users under a source-available licence. Essential Open Source is the other free multi-user repository, at the cost of a steeper modelling client. Archi is the reference free ArchiMate modeller for a single architect who needs a precise notation. ADOIT Community Edition is a real EA repository in the cloud but is limited to one user. Modelio, Structurizr, IcePanel and draw.io are free modelling or diagramming tools that produce good pictures and do not maintain an application inventory. Sparx Enterprise Architect is not free, but its perpetual desktop licence is inexpensive enough to belong in a budget shortlist, and iteraplan, which still appears on many lists, has not been open source since 2014.
Turbo EA is self-hosted by design, so your architecture data stays on your own infrastructure. If a SaaS platform with vendor support is preferable for your organisation, SAP LeanIX is the closest commercial equivalent, and the author of Turbo EA implements SAP LeanIX as well, so the choice between the two can be made on your requirements rather than on who is advising you.
Six facts per tool, taken from the vendor’s own site. A cell that says “confirm with the vendor” means the vendor page did not state it, never that the tool lacks it.
| # | Tool | Licence and cost | What it is | Multi-user repository | Self-hosted | Best suited to |
|---|---|---|---|---|---|---|
| 1 | Turbo EA | FreeFSL-1.1-MIT, source on GitHub. No seat limit, no trial, no feature cap. | EA repository with BPMN, portfolio management and TOGAF artefacts | YesPostgreSQL, roles, SSO, unlimited users. | YesDocker Compose, air-gap capable. | Teams that need a shared application and capability inventory with reports |
| 2 | Essential Open Source | FreeGNU GPL. Essential Cloud and Essential Docker are the paid editions. | EA repository with a Protégé-based modelling client and a web viewer | YesMulti-user install on MySQL, PostgreSQL or SQL Server. Single-user “Essential in a Box” also available. | YesJava 8, Tomcat 8.5 or 9. Vendor quotes 3 to 6 hours for a multi-user install. | Teams with a Java administrator who want a mature, free repository and can live with the Protégé editor |
| 3 | Archi | FreeMIT. Some plug-in binaries are reserved for Patreon or PayPal supporters. | Desktop ArchiMate modelling tool | Via gitFile-based. The free coArchi plug-in shares models through a git repository. | DesktopWindows, macOS and Linux. Nothing to host. | An architect who needs a precise, standards-based notation |
| 4 | ADOIT Community Edition | FreeVendor states “free forever”. One seat. Paid ADOIT Grow starts at EUR 1,195 per month for five seats, billed annually. | Cloud EA repository, free tier of the commercial ADOIT suite | Single userOne seat, one language, limited number of objects and models. | NoHosted by BOC Group on a shared application stack. | One architect who wants a proper repository without running a server |
| 5 | Modelio | FreeGPL-3.0 on GitHub. Modeliosoft sells commercial editions. | Desktop UML, BPMN and SysML modeller with an ArchiMate extension | Confirm with the vendorThe open source edition works on local projects. Team features are not documented on the open source site. | DesktopNothing to host. | Architects who also model in UML or SysML and want one tool for all three |
| 6 | Structurizr | Partly freeDSL, CLI and Lite are free and open source. Server binaries and the cloud service require a licence. | C4 model “models as code” for software architecture | LimitedLite is single user and listed as end of life. The self-hosted server has a free open core when built from source. | YesDocker or Spring Boot. | Engineering teams that want software architecture diagrams generated from code in version control |
| 7 | IcePanel | Free plan5 editors, unlimited viewers, 100 model objects. Growth plan USD 40 per editor per month, billed annually. | Browser-based C4 modelling tool | CappedShared model, but the free plan stops at 100 objects, one landscape and one domain. | NoCloud service. | A small engineering team documenting one system together |
| 8 | draw.io | FreeApache 2.0. Web, desktop app and a Docker image. | General diagramming tool with an ArchiMate shape library | NoEach diagram is a file. Nothing links the same element across diagrams. | YesOfficial Docker image, or the desktop app. | A one-off landscape picture, or diagrams attached to a repository that holds the facts |
What each tool is, what it costs, how it is hosted, how a team works in it, and the thing it is not.
Turbo EA is a self-hosted Enterprise Architecture Management platform. It catalogues applications, business capabilities, technologies, data objects and the relations between them on an admin-configurable metamodel that ships with 13 card types and 45 relation types, and it generates more than ten interactive reports from that data, including a capability heatmap, lifecycle roadmap, dependency graph and cost treemap. It bundles three things that commercial suites tend to sell separately: a native BPMN 2.0 process editor, project portfolio management with Gantt, work breakdown and budget tracking, and a TOGAF Statement of Architecture Work editor with sign-off workflow. A built-in MCP server lets AI clients read and write the repository under each user’s own permissions.
Multi-user from the first install, with single sign-on through Entra ID, Google, Okta or any OIDC provider and custom roles with more than 50 granular permissions. Your data stays in a PostgreSQL database you control, nothing is sent back to the supplier, and the whole stack runs air-gapped if it has to. A dedicated LeanIX importer and an Excel and CSV bulk importer cover migration, and REST, OData and DOCX exports get everything out again. Diagrams are drawn in an embedded draw.io editor with the repository as the source of truth, so it is not an ArchiMate notation tool. Paid implementation, sponsored development and advisory are available from the author for teams that want help, and the comparison with commercial platforms covers the cases where a vendor-supported product is the better fit.
Turbo EA has no hosted edition. If you would rather have a SaaS platform than run Docker, SAP LeanIX is the closest commercial equivalent, and the author implements it too.
The Essential Project has been publishing a free EA repository for well over a decade, and it remains the most complete open source option next to Turbo EA. The open source edition is built on the Protégé ontology editor, which holds the Essential Meta-Model, and on Essential Viewer, a Java web application on Tomcat that publishes reports and views over the captured architecture. An import utility loads spreadsheets. The current downloads at the time of writing are meta-model 6.21, Viewer 6.21.7 and the single-user “Essential in a Box” bundle at version 6.21.1, so the project is actively maintained.
A multi-user install runs on MySQL, PostgreSQL or SQL Server with Java 8 and Tomcat 8.5 or 9, and the vendor quotes three to six hours to set it up. The honest caveat comes from the vendor itself: data capture in the open source edition “requires some understanding of the meta model”, while the paid Essential Cloud and Essential Docker editions add form-based editors, APIs and a security model. It is not an ArchiMate tool, and the Protégé client is a technical interface that business stakeholders will not open. If your team has a Java administrator and a patient modeller, it is a serious free choice.
Archi is the free ArchiMate modelling tool that almost every enterprise architect has opened at least once. Version 5.10.0 was released on 3 September 2026 and supports the ArchiMate 3.2 specification, and the project reports roughly six thousand downloads a month. It is a desktop application that edits a model file, with views, a model tree, properties, validation and export to the ArchiMate Exchange Format, so anything you build in Archi can move to another ArchiMate tool later.
Collaboration is the limit. The free coArchi plug-in (version 0.9.7) shares a model through a git repository, which works well for a small architecture team that is comfortable with commits and merges. Its rewrite, coArchi2, and the jArchi scripting plug-in are open source on GitHub, but the compiled binaries are distributed to Patreon members and PayPal contributors, so budget a small donation if you need them. Archi is a modeller, not a portfolio repository: it has no application owners, no lifecycle dates and no reports across the estate unless you script them.
ADOIT is BOC Group’s commercial EA suite, and the Community Edition is its free tier, launched in 2013 and described by the vendor as “free forever, no catch”. It is a genuine repository rather than a drawing tool, with ArchiMate 3.1 certification, an Excel import and support for the ArchiMate Exchange Format, so a single architect gets the same working model as the paid product without installing anything. Note the product name: some roundups list “ADONIS Community Edition” as an EA tool, but ADONIS is BOC’s business process suite. The EA product is ADOIT.
The vendor’s pricing page states the limits: one seat, one language, a limited number of objects and models, community support and a shared application stack. That makes it a good single-user workbench and not a team tool. The next step up, ADOIT Grow, starts at EUR 1,195 per month for five seats billed annually, with the vendor noting that prices are indicative and vary by region. It cannot be self-hosted, so your architecture data lives on BOC’s infrastructure.
Modelio is an open source modelling environment that covers UML2, BPMN2, SysML and, through a downloadable extension, ArchiMate, with TOGAF and MDA listed among its supported standards. The open source project lives on GitHub under ModelioOpenSource, where the latest release is 6.2.0, and the original modelio.org site currently points visitors to GitHub while it is rebuilt. It is the natural pick when the same person has to produce system design in UML or SysML and architecture views in ArchiMate, because one tool holds all of it.
Like Archi, it edits local projects. Team repositories and support are part of Modeliosoft’s commercial offering, and the open source site does not document multi-user features, so confirm with the vendor if you need them. It is not an application portfolio tool and has no reports over an inventory.
Structurizr is the “models as code” tool built by the author of the C4 model. You describe a system, its containers and components in a text DSL kept in version control, and the tool renders consistent diagrams from that single model, which is the property most diagramming tools lack. The DSL and CLI are free, and Structurizr Lite, a single-user local viewer and editor, is free and open source, though the documentation now lists Lite and the on-premises installation under end of life. The self-hosted server has an open core that is free when built from source, while the prebuilt binaries with enterprise features such as SAML and role-based access require a licence.
It is a software architecture tool, not an enterprise architecture tool. C4 describes one system at a time and has no concept of business capabilities, application ownership or lifecycle across a portfolio. It is included here because engineering teams searching for a free architecture tool often mean this, and it is very good at what it does.
IcePanel is a browser-based C4 modelling tool with a drag-and-drop editor, and it takes the same model-first approach as Structurizr with a gentler learning curve. The free plan allows five editors, unlimited viewers, unlimited diagrams and up to 100 model objects in one landscape and one domain, with two tag groups, one flow per diagram and three decision records per landscape. For a small team documenting a single system, that is enough to get real work done at no cost.
The caps are the point of the free plan, and 100 objects is exhausted quickly once you model more than one system. It cannot be self-hosted, and like Structurizr it works at the software architecture level rather than across a business and application portfolio.
draw.io, also known as diagrams.net, is the free diagramming tool most architects already use, and it ships an ArchiMate shape library, so it appears on nearly every list of free EA tools. It is included here to say clearly what it is. Every diagram is an independent file. The same application drawn in five landscape diagrams is five unrelated rectangles, nothing records who owns it or when it reaches end of life, and there is no report to run across the set.
That makes it excellent for a one-off picture and unsuitable as the system of record for an application inventory. The productive pattern is to keep the facts in a repository and draw from them, which is why Turbo EA embeds a self-hosted draw.io editor rather than trying to replace it.
One inexpensive perpetual licence that belongs next to the free tools, and one product that is often listed as free and is not.
Sparx Systems has sold Enterprise Architect as a one-time desktop licence for more than twenty years, in Professional, Corporate, Unified and Ultimate editions. It models in UML, SysML, BPMN and ArchiMate and covers TOGAF through its framework technologies, which is why it sits in so many architecture teams. A shared model for a team runs on a database repository, and the browser-based Pro Cloud Server is licensed separately, so the cheap entry price applies to a single modeller rather than a collaborative deployment. Sparx does not publish a free edition, so it is not in the ranked list, but for a lone architect who wants a heavyweight modeller for the price of a dinner it remains the reference budget option.
iteraplan, from the German consultancy iteratec, was one of the first open source EA management tools and was published under the AGPL. Since October 2014 the source code has no longer been available under that licence and development has continued as a proprietary product. It still appears in current roundups as “free, open source”, which is more than a decade out of date. It is a capable commercial IT landscape management tool, and it has no free edition, so it is listed here only so that you do not spend an afternoon looking for a download that no longer exists.
Two other open source projects are often mistaken for EA tools and are left off the list on purpose. Backstage is a developer portal with a software catalogue, which is a fine inventory of services and their owners for an engineering organisation but has no business capability, process or strategy layer. Eclipse Capella is a model-based systems engineering tool for the Arcadia method, aimed at designing a physical or embedded system rather than an enterprise’s application landscape.
The right free tool depends far more on who will use it and what they need to answer than on features.
If the question is “which applications do we run, who owns them, what do they cost and when do they retire”, you need a multi-user repository with reports. Turbo EA or Essential Open Source. Nothing file-based will survive the second quarter of maintenance.
If your practice writes in ArchiMate and exchanges models with other teams or tools, Archi is the right start and its Exchange Format export keeps the door open. Modelio if UML or SysML sit beside it. Structurizr or IcePanel if the subject is one software system in C4.
ADOIT Community Edition gives a lone architect a real cloud repository with ArchiMate for nothing, with the one-seat and object limits accepted up front. Archi on your laptop is the other zero-infrastructure answer.
None of the free editions on this page comes with a hosted service and a service level agreement. If your organisation wants what Turbo EA does as a SaaS platform with a vendor behind it, SAP LeanIX is the closest equivalent, and the author of Turbo EA offers SAP LeanIX implementation and governance alongside Turbo EA rollouts. Turbo EA ships a LeanIX importer, so moving between the two later is a supported path.
Questions about Turbo EA itself are answered on the Turbo EA FAQ page.
Yes, two. Turbo EA and Essential Open Source are both multi-user EA repositories that you install on your own server, and neither charges per seat or caps the number of users. Turbo EA is published under the Functional Source License (FSL-1.1-MIT) and deploys with Docker Compose. Essential Open Source is published under the GNU General Public License and runs as a Protégé-based modelling client with a Java web viewer on Tomcat. Every other free option on this page is either restricted to one user (ADOIT Community Edition), capped on model size (IcePanel free plan), or a file-based modelling tool rather than a shared repository (Archi, Modelio, Structurizr, draw.io).
A modelling tool such as Archi or Modelio edits a model file. It gives one architect a precise notation, and the model lives on that person’s disk until it is shared through git or a shared drive. An EA repository such as Turbo EA, Essential or a commercial platform stores applications, capabilities, technologies and their relations in a database that many people edit at the same time, and it generates reports such as capability heatmaps, lifecycle roadmaps and cost views from that shared data. Most organisations that search for a free EA tool actually need the repository, because their problem is an application inventory with owners and lifecycles, not a diagram.
No. iteraplan was released by iteratec under the AGPL and was one of the first open source EA management tools. Since October 2014 the source code has no longer been available under the AGPL and development has continued under a proprietary licence. Several current roundups still list it as a free open source tool, which is more than a decade out of date. If you want a self-hosted open source EA repository today, the two options are Turbo EA and Essential Open Source.
You can draw architecture diagrams in draw.io, and it ships an ArchiMate shape library, but it is a diagramming tool, not an EA tool. Each diagram is an independent file, so the same application drawn in five diagrams is five unrelated boxes, nothing tells you who owns it or when it reaches end of life, and there is no report to run across the set. It is a good choice for a one-off landscape picture and a poor choice for an inventory you intend to maintain. Turbo EA embeds a self-hosted draw.io editor for exactly that reason: the repository holds the facts and draw.io draws them.
TOGAF is a method rather than a notation, so support means different things in different tools. Archi models in ArchiMate, which is The Open Group’s notation aligned with TOGAF, and Modelio lists TOGAF among its supported standards. Turbo EA ships TOGAF governance artefacts directly: a Statement of Architecture Work editor with sign-off workflow and DOCX export, architecture decision records, an EA risk register aligned to Phase G and an admin-curated set of architecture principles. Essential Open Source is framework-independent and documents how its meta-model maps onto TOGAF. If your practice runs the Architecture Development Method end to end, the deliverables and sign-offs matter more than the notation, and that favours a repository over a modeller.
No. Turbo EA is self-hosted only, because keeping the architecture repository on your own infrastructure is the point of the product. If a SaaS platform with vendor support is preferable for your organisation, SAP LeanIX is the closest commercial equivalent in scope: an application and technology inventory, a configurable metamodel, capability mapping and lifecycle reporting, delivered as a subscription. The author of Turbo EA holds an SAP LeanIX certification and implements it for organisations that choose that route, and Turbo EA includes a LeanIX importer with field mapping and a staged review, so an inventory built in LeanIX can be moved into Turbo EA later.
It runs in the browser on GitHub Codespaces with a sample landscape of more than 150 cards already loaded, or on your own server with one Docker Compose file. No registration, no trial period, no seat limit.
SAP and LeanIX are trademarks of SAP SE. Archi is a registered trademark of Phillip Beauvoir. ArchiMate and TOGAF are registered trademarks of The Open Group. ADOIT and ADONIS are trademarks of BOC Group. Modelio, Structurizr, IcePanel, draw.io, Enterprise Architect, iteraplan, Backstage and Capella are trademarks of their respective owners. Turbo EA is an independent project and is not affiliated with, endorsed by or sponsored by any of them. Facts on this page were checked on 29 September 2026 and products change, so verify anything decision-critical with the vendor. If something here about your product is wrong or out of date, send a correction and it will be fixed with a dated note.