The short answer
One thing to state before the profiles, so nobody reads this page under a false impression: MiniPACS is not open source. It is a commercial, self-hosted PACS built on the same philosophy, your data stays in your hands, not a vendor's cloud, whether it runs on hardware in your building or on a cloud server in an account you control, that ships already assembled. Where that fits, and where it honestly does not, is covered after the projects themselves.
The real open-source players
Orthanc: the lightweight DICOM server
Orthanc is the default answer for a reason. It is a lightweight, standalone DICOM server with a REST API, Lua scripting, and a plugin ecosystem that covers most of what a small archive needs: PostgreSQL storage, DICOMweb, the Stone Web viewer. It installs in minutes, runs on modest hardware, and is maintained by people who care about DICOM correctness. It is not a toy: production imaging stacks run on it, including MiniPACS's own engine. What Orthanc deliberately does not include is the clinic layer: a front-desk worklist, staff roles, an audit trail, automated tested backups, a support line. The Orthanc alternative page walks that gap in detail.
dcm4chee: the enterprise archive
dcm4chee is the heavyweight of open-source imaging: a Java-based archive from the dcm4che project, built for hospital scale and IHE workflow profiles. Where Orthanc is a compact server you script around, dcm4chee is closer to a commercial VNA in scope. The trade is operational weight: a Java application server, LDAP, a database, and configuration that assumes an administrator who has run enterprise Java before. For a hospital IT department that has that person, dcm4chee is a serious, proven option. For a three-person clinic it is usually the wrong amount of machine. The dcm4chee alternative page covers the day-two reality.
Dicoogle: research and indexing
Dicoogle is an open-source platform from the research world, and that is its honest home. Its strength is indexing: plugin-based full indexing of DICOM metadata so you can query large collections in ways a standard archive query cannot. For dataset curation, academic projects and imaging research it is genuinely useful. It was never designed to be a clinic's daily archive, and using it as one means building even more around it than you would around Orthanc.
OHIF: a viewer, not a PACS
OHIF is the open-source web viewer, zero-footprint, browser-based, and good enough that commercial products ship it. But it stores nothing. OHIF speaks DICOMweb to an archive behind it, most commonly Orthanc or dcm4chee, and without one it is a screen with no film. It belongs in an open source PACS conversation as a component, not a candidate. For what separates viewers from archives in general, see DICOM viewer.
Horos and Weasis: desktop viewers, not archives
Horos is a free macOS viewer descended from OsiriX: a capable radiologist workstation whose maintenance has visibly slowed in recent years. Weasis is a free cross-platform desktop viewer, usually launched from an archive to display a study. Both are viewers that live on one workstation; neither receives from your modalities, indexes patients or serves other users. Clinics sometimes use a desktop viewer plus a shared folder as an accidental PACS, and that arrangement fails exactly where you would expect: no archive, no backups, no concurrent access. The Horos and Weasis pages take each on its own terms.
Open source PACS with a built-in viewer: what actually exists
Only Orthanc and dcm4chee are genuine open-source PACS archives. Orthanc ships a basic Stone Web Viewer plugin that is not intended for primary diagnostic interpretation; dcm4chee has no native viewer at all and is commonly paired with the Weasis desktop viewer. If you specifically want an open source PACS alternative to Orthanc with a supported zero-download browser viewer already built in, the closest assembled option is MiniPACS, which is a commercial product, not an open source project.
| Open source (Orthanc, dcm4chee) | MiniPACS | |
|---|---|---|
| Licensing | Open source, free license (Orthanc is GPLv3) | Commercial, flat $300 per location per month |
| Built-in web viewer | Orthanc bundles a basic Stone Web Viewer plugin; dcm4chee has none and is usually paired with Weasis | Zero-download Stone Web Viewer and OHIF in the browser, built in |
| Diagnostic-grade viewer | Bundled Stone and Weasis viewers are not cleared for primary diagnostic interpretation | Not marketed as an FDA-cleared diagnostic device |
| Setup and ops | You deploy the archive, wire the viewer, secure it and maintain the stack yourself | Installs with Docker on Linux, viewer wired in, runs on a mini PC per site |
| Best for | Teams with engineering capacity that want source they can audit and fork at zero license cost | Clinics that want the self-hosted outcome already assembled, with support |
What you assemble yourself
Pick Orthanc or dcm4chee and you have solved the archive, which is the best-solved part of the problem. What remains is the difference between a DICOM server and a system a clinic runs on:
None of this is a criticism of the projects; it is their stated scope. If you want to walk the DIY route with open eyes, the how to self-host a DICOM server guide is the honest step-by-step, and self-hosted PACS covers the deployment model itself.
Where MiniPACS fits, stated honestly
MiniPACS is not an open-source project and does not pretend to be one. It is a commercial self-hosted PACS: paid, supported, and built for clinics that want the self-hosted outcome, data on hardware they control, whether on site or in their own cloud account, no per-study cloud bill, without an engineering project. Full disclosure, because it matters in this conversation: MiniPACS runs Orthanc as its DICOM engine internally. The product is the assembled layer around that engine, the part this page just listed as yours to build.
Assembled means: C-STORE ingest from any modality and C-STORE send with C-ECHO for network checks, DICOM TLS, a DICOMweb layer that is gated to the LAN and serves both Stone and OHIF viewers in the browser, a worklist, reports as encapsulated PDFs that travel inside the study, share links, remote reading over an outbound-only tunnel rather than an open port, and a gateway agent for the modality side. It installs with Docker on Linux, runs on a mini PC for a single site, and holds millions of images in production. Pricing is a flat $300 per location per month; if the subscription lapses the system goes read-only and your archive stays yours, in standard DICOM, on your disk. Details on the pricing page, and the landing page has a live demo.
Who should not buy it: if your requirement is source code you can audit and fork, zero license cost, or deep customization of the archive itself, MiniPACS is the wrong product and Orthanc is the right starting point. That is not false modesty; it is the actual boundary.
That is not false modesty; it is the actual boundary.
MiniPACS is the assembled, supported layer around the same open-source DICOM engine, at a flat $300 per location per month; click through the live demo before you commit engineering time to a DIY build.
Open source or assembled: how to choose
Choose open source when you have real engineering capacity, in-house or contracted, and the archive is worth that capacity to you: you want maximum control over every component, the freedom to modify and integrate without a vendor, and a license cost of zero. Hospital IT departments, imaging research groups and technically-staffed teleradiology outfits fit this profile, and for them the open-source stack is not a compromise, it is the better system.
Choose an assembled self-hosted PACS when the clinic has no one whose job is to build and maintain imaging infrastructure. The archive still sits on hardware you control, in the clinic or on a cloud server in an account you hold, and the data is still yours; what you are paying for is the assembly, the upgrades and the phone number. The failure mode this avoids is specific and common: a DIY install that worked on day one and stopped being maintained the month its builder got busy. Which of the two actually costs less depends on who is on staff to do the work; the cheap PACS breakdown walks through that math.
| Open-source stack, DIY | MiniPACS, assembled | |
|---|---|---|
| Archive | Orthanc or dcm4chee, you deploy and tune | Included, C-STORE ingest from any modality |
| Viewer | OHIF or Stone, you wire to the archive | Stone and OHIF in the browser, included |
| Worklist | You build it | Included |
| Reports | You build it | Encapsulated PDFs that travel with the study |
| Backups | You script and test them | Included |
| Remote reading | VPN you configure | Outbound-only tunnel, no open ports |
| Support | Forums and mailing lists | A person who answers |
| Cost | $0 license, ongoing engineering time | $300 per location per month, flat; read-only on lapse, never locked out |
FAQ
Is MiniPACS open source?
No. MiniPACS is a commercial, paid product. It is self-hosted, so the archive runs on hardware you control, either in your building or on a cloud server in an account you hold, and the imaging data stays in your hands rather than a vendor's, and it uses the open-source Orthanc server as its DICOM engine internally, but the product around that engine, the worklist, the reports, the backups and the support, is a paid product: a flat $300 per location per month. If open source is a requirement for you, Orthanc and dcm4chee are the real options, and this page describes them fairly.
What is the best open source PACS?
For most small and mid-sized deployments, Orthanc: it is lightweight, well documented, actively maintained, and its plugin ecosystem covers DICOMweb, PostgreSQL storage and the Stone Web viewer. For hospital-scale archives with IHE workflow requirements and a team that runs Java enterprise software, dcm4chee is the more complete archive. There is no single best; there is a best fit for the engineering capacity you actually have.
Is Orthanc a complete PACS?
It is a complete DICOM server and archive, and a genuinely good one, but not a complete clinic system. Out of the box it has no worklist built for a front desk, no staff roles, no automated tested backups and no support line. Those are deliberate non-goals: Orthanc is the engine, and its maintainers expect you to build or bolt on the rest. Plenty of teams do exactly that; the honest question is whether yours is one of them.
Is OHIF a PACS?
No. OHIF is a web-based DICOM viewer, and a very good one, but it stores nothing. It needs an archive behind it that speaks DICOMweb, most commonly Orthanc or dcm4chee. If you see OHIF listed as an open source PACS, that listing is wrong: it is one component of a PACS, the screen, not the storage.
What does a free open source PACS actually cost to run?
The license is zero and stays zero. The cost is engineering time: the initial assembly of viewer, worklist, access control, TLS and backups, and then the permanent tail of upgrades, security patches, restore drills and being the person who answers when it breaks at 8am. For a team that already has that capacity, the total cost can genuinely beat any commercial option. For a clinic without it, the free license is the cheapest line item in an expensive project.
Can I run an open source PACS in a HIPAA-covered clinic?
Yes, there is no rule against open source software in a covered entity. Compliance is about how the system is run, not who wrote it: access controls, audit trail, encryption, tested backups and the written policies around them. Open source gives you full control to implement all of that, and full responsibility for actually doing so. A commercial self-hosted product does not make you compliant either; it just ships more of those controls pre-built.
Does Orthanc have a built-in viewer?
Yes, in a limited sense. Orthanc ships a basic Stone Web Viewer plugin, so you can open studies in a browser without extra software, but that bundled viewer is not intended for primary diagnostic interpretation. dcm4chee, the other genuine open-source PACS archive, has no native viewer at all and is commonly paired with the Weasis desktop viewer. If you need a supported, zero-download browser viewer built into the product itself, that is where an assembled option like MiniPACS differs, though MiniPACS is a commercial product, not an open source project.
Which open source PACS has a built-in web viewer, and what is the commercial alternative?
Among genuine open-source PACS archives, only Orthanc ships a built-in web viewer out of the box: its basic Stone Web Viewer plugin, which is not intended for primary diagnostic interpretation. dcm4chee has no native viewer and is usually paired with the Weasis desktop viewer. The closest commercial alternative that assembles a supported zero-download browser viewer, Stone Web Viewer and OHIF, directly into the product is MiniPACS, which runs Orthanc as its DICOM engine internally but is itself a paid product at a flat $300 per location per month, not open source.
