This guide is for dentists, practice IT staff and dental students who need to open a CBCT scan, a CT disc from an imaging centre, or panoramic and intraoral X-rays exported as DICOM, without buying a viewer licence. It covers the free DICOM viewers in our catalogue, what each one is still good for, and what a clinic should install today.
The short answer: most of the free viewers that still appear on download sites are old. Of the programs below, only HorliX (Mac) received an update in 2026. DicomWorks, Aeskulap and JDicom are no longer developed, and ONIS 2.5 Free Edition is a limited edition of a commercial line whose official requirements end at Windows 8. For a new installation, start with a maintained open-source viewer: Weasis on Windows, macOS or Linux, or Horos on a Mac. Keep the older tools for the specific jobs described below.
The short list
| Program | Best for | Licence | Platforms | Status |
|---|---|---|---|---|
| HorliX | CBCT review with MPR on a Mac | Free (LGPL v3 source) | macOS 12.4+ | Minimal maintenance; 1.1.2 released August 2026 |
| DicomWorks | Opening DICOM CDs, anonymising, exporting JPEG or PowerPoint slides | Free (freeware) | Windows | Legacy; no updates since 2011 |
| Aeskulap | Simple 2D viewing and PACS query on Linux | Free, open source (GPL) | Linux (old Windows build) | Discontinued; last stable release 2006 |
| ONIS 2.5 Free Edition | MPR and MIP on Windows for a handful of patients | Shareware (conditionally free) | Windows | Legacy; the 2.x line has stopped |
| JDicom | Testing DICOM connections (not a viewer) | Free (closed source) | Java (Windows / Linux) | Abandoned since about 2005 |
| Weasis | Everyday viewing in a modern clinic, including MPR and 3D | Free, open source (EPL 2.0 / Apache 2.0) | Windows, macOS, Linux | Maintained; 4.7.3 released August 2026 |
| Horos | Mac clinics, including Apple silicon | Free, open source (LGPL) | macOS | Maintained; 4.0.1 supports macOS 26 Tahoe |
HorliX: free DICOM viewer for Mac
HorliX is a macOS viewer derived from Horos and OsiriX, developed by Hiroaki Inomata, MD (PHAZOR). It imports studies into a local database and offers a 2D viewer with window/level, multiplanar reconstruction (MPR) and ROI measurement. That covers routine CBCT review: scrolling axial slices and checking a lower third molar or an edentulous ridge in cross-section. Version 1.1.2 needs macOS 12.4 or later.
The limits are real. It is Mac only, it depends on OpenGL, the developer labels the builds “trial” and “use at your own risk”, and he says HorliX receives very little maintenance. His successor app, PHORLIX, targets Apple silicon. There are no dental tools such as panoramic curves or nerve tracing. Pick HorliX if you already know its interface; on a new Mac, Horos is the safer default.
DicomWorks: legacy Windows viewer and anonymiser
DicomWorks was written by two French radiologists and is still served from its official site as build 1.3.5b. It opens DICOM folders and CDs with a DICOMDIR and reads compressed and multi-frame files. Its most useful tools today are tag anonymisation and export to JPEG, BMP, AVI or straight into PowerPoint, which makes it handy for lecture slides and case reports.
It has no 3D rendering, no MPR and no dental tools, so a CBCT volume can only be scrolled slice by slice. It was built for Windows 95 to XP, and support for Windows 10 or 11 was never confirmed, so test it before relying on it. Use it as a quick converter, not as the clinic’s main viewer.
Aeskulap: open-source viewer for Linux (discontinued)
Aeskulap is a GPL viewer and PACS client by Alexander Pipelka. It loads DICOM series, queries and retrieves studies from a PACS (C-FIND, C-MOVE), shows reference lines between views and lets you save window-level presets. On Debian 12 or Ubuntu 22.04 it installs from the standard repositories as the aeskulap package.
Development ended long ago: the last stable release is 0.2.1 from 2006, and the package is missing from Debian 13 and Ubuntu 24.04. There is no official “portable” edition, no MPR or 3D, and no anonymisation or export. It suits a Linux teaching room or an old Linux workstation. On a current Linux PC, Weasis is the practical replacement.
ONIS 2.5 Free Edition: MPR on Windows, with limits
ONIS 2.5 Free Edition from DigitalCore (Tokyo) is the most capable Windows option in our catalogue. It reads DICOM from any modality, imports from CDs, folders or a PACS, and offers single oblique MPR, MIP volume rendering and a full set of measurement tools. For a dentist who occasionally opens a CBCT disc, that is enough to check a site in coronal and sagittal planes.
It is shareware (conditionally free): the local database holds 15 patients, only one monitor is supported, and anonymisation, calibration and DICOMDIR export are disabled. Official system requirements stop at Windows 8, and the free package stayed on version 2.5. Pick it for light, occasional use on Windows, and clear old studies as you go.
JDicom: a DICOM toolkit, not a viewer
JDicom appears in many “free DICOM viewer” lists, but it is a different kind of tool. TIANI Medgraph built it around 2000 as a set of Java utilities for sending, receiving, querying, printing, editing and validating DICOM objects. Its users were PACS administrators and engineers checking why a modality could not talk to an archive.
In a dental practice that could mean testing whether a CBCT unit can send a study at all, or checking why a file breaks a viewer. It gives you no MPR and no clinical review screen. The last known version is 1.7.35, the official site survives only in web archives, and the software has had no security updates for about twenty years. For the same jobs today, IT staff use the open-source dcm4che tools, written by the same original author.
What a modern clinic should install instead
Two maintained, free viewers cover most practices. They are not in our catalogue yet; the facts below come from their official sites.
- Weasis is a free, open-source viewer (EPL 2.0 / Apache 2.0) for Windows, macOS and Linux. It opens CT, X-ray and other DICOM studies from folders, USB drives and CDs, connects to a PACS, and offers MPR, 3D, calibrated measurements and multi-monitor support. Version 4.7.3 was released in August 2026. Its developers state that the open-source distribution is not a certified medical device (CE or FDA).
- Horos is a free, open-source (LGPL) viewer for macOS only. Version 4.0.1 supports Apple silicon and macOS 26 Tahoe. It is the natural choice for a Mac-based practice.
For daily CBCT diagnosis, the software supplied by your CBCT manufacturer usually remains the main tool, because it has dental reconstructions such as panoramic curves and nerve tracing that general viewers lack. A free viewer is the second seat: the front desk, the home office, the lecture laptop.
Where implant-planning viewers fit
If you received a guided-surgery plan rather than raw DICOM, you need the planning vendor’s viewer. Simplant Viewer and Simplant Editor are Dentsply Sirona’s free tools for reviewing and approving plans from the Simplant Planning Service. They open Simplant cases only, not your own CBCT files. For scan and design files (STL, PLY), see our guide to free dental CAD viewers.
How to choose
- Check what you actually have. A folder of
.dcmfiles or a disc with a DICOMDIR opens in any viewer here. Intraoral sensor images often live inside the imaging software’s own database, so export them as DICOM first. - Match your operating system. Windows: Weasis, or ONIS 2.5 Free Edition for light use. Mac: Horos, or HorliX if you already use it. Linux: Weasis, or Aeskulap on older distributions.
- Decide whether you need cross-sections. For CBCT you want MPR at minimum. That rules out DicomWorks and Aeskulap.
- Check the patient count. ONIS Free Edition keeps 15 patients; the open-source viewers have no such limit.
- Protect patient data. Anonymise before any teaching use, and look for names burned into the pixels, which tag anonymisation does not remove.
- Do not treat a free viewer as a certified workstation. None of the free tools here claims regulatory clearance for primary diagnosis. Rely on your CBCT vendor’s software and the radiology report for clinical decisions.
FAQ
What is the best free DICOM viewer for a dental clinic?
For a new installation, a maintained viewer: Weasis on Windows, macOS or Linux, or Horos on a Mac. Both are free and open source, show CBCT data in MPR, and still receive updates.
Is there a free DICOM viewer for Mac?
Yes. Horos and HorliX are free macOS viewers from the OsiriX family, and Weasis also runs on macOS. On an Apple silicon Mac, Horos 4.0.1 is the more future-proof choice.
Is there a free dental X-ray viewer?
If the X-ray is stored as DICOM, any viewer on this page opens it. Panoramic and intraoral images kept in a vendor’s imaging database need to be exported first, or opened with the viewer that vendor provides.
What is HorliX?
A free Mac DICOM viewer based on Horos and OsiriX. The name has nothing to do with the malted milk drink: the developer says it combines Horos and OsiriX and refers to a racehorse named Horlicks.
Is DicomWorks still available?
The official site still offers build 1.3.5b, but it has not been updated since 2011. It runs on Windows only and was designed for Windows 95 to XP.
Is Aeskulap still developed?
No. The last stable release is 0.2.1 from 2006, and its GitHub repository is archived. It is still packaged in Debian 12 and Ubuntu 22.04, but not in newer releases.
Last updated: 26 September 2026 · Dents-Soft editorial team. Licence, version and platform details are checked against each developer's official documentation; none of the tools listed here should be treated as a certified medical device unless its vendor says so.
