This guide is for dentists, dental technicians, students and clinic IT staff who have a DICOM disc or folder (a CBCT export, a panoramic image, a CT from a radiology centre) and need to open it on a Windows 10 or Windows 11 PC without buying software.
The short answer: for a quick look on a current Windows PC, try the free MicroDicom viewer first. It is free for non-commercial use, its official site lists Windows 10 and Windows 11, and it has a portable ZIP that runs without installation. If you also need multiplanar views, ONIS 2.5 Free Edition is the older but more capable option. DicomWorks still works as an anonymiser and image exporter, but it was built for Windows XP-era systems and has had no updates since 2011.
The short list for Windows 10 and 11
| Viewer | Best for | Licence | Windows status |
|---|---|---|---|
| MicroDicom | Quick look at a CD or folder, anonymising, exporting | Free for non-commercial use | Windows 10 and 11 listed on the official site; installer and portable ZIP |
| Weasis | Clinic IT teams that want an open-source viewer | Free, open source (EPL 2.0 and Apache 2.0) | Desktop distribution for Windows, macOS and Linux |
| ONIS 2.5 Free Edition | MPR and MIP views, PACS queries | Shareware (conditionally free) | Officially XP SP3 to Windows 8; development has stopped |
| DicomWorks | Anonymising and exporting images | Free (freeware) | Built for Windows 95 to XP; legacy, no updates since 2011 |
| Aeskulap | Linux workstations | Free, open source (GPL) | Only an old 0.2.1 Windows installer; not a current Windows option |
What “works on Windows 11” really means
Most of the free DICOM viewers people find first are old. A vendor that never tested Windows 11 does not claim it works there, and we do not claim it either. Many 32-bit programs from the Windows 7 era still start on Windows 10 and 11, but “starts” is not the same as “supported”. Before you rely on any old viewer, test it on a copy of a real case, and check that the images, the measurements and the export all behave.
The only viewer in the list above whose own site names Windows 10 and Windows 11 is MicroDicom. For the others, treat the platform column as the vendor’s stated target, not a promise.
MicroDicom: the practical first choice
MicroDicom is a Windows viewer with a current release line: its download page lists version 2026.4 with a standard installer and portable ZIP packages for 64-bit and 32-bit Windows, plus an autorun package meant for putting a viewer on a CD, DVD or USB drive. The vendor says it is free for non-commercial use and that commercial use requires a purchase, so a practice should read the licence terms before installing it on clinic PCs.
The vendor’s page describes opening DICOMDIR files and patient CDs, anonymising images, measurements and annotations, and exporting to JPEG, BMP, PNG, GIF and TIFF, as well as to movie files. It does not mention 3D or MPR, so we do not claim them. The vendor also states that the program has no CE mark and no FDA approval and must not be used for clinical purposes or to affect patient management. Use it to look at and share images, not to make diagnoses.
Because MicroDicom is not in our catalogue, we have not tested it and there is no program page for it here. The facts above come from its official site.
Weasis: open source, with a note for IT
Weasis is a DICOM viewer released under the EPL 2.0 and Apache 2.0 licences, with desktop distributions for Windows, macOS and Linux. Its documentation says that since version 4 only the distribution with a native installer is maintained, and it marks version 4.7 as current. It is a good choice if you want an actively developed open-source tool and your IT staff can install and update it. The project pages we checked make no statement about clinical or diagnostic use, so assume it is for viewing and research unless you confirm otherwise with the project.
ONIS 2.5 Free Edition: when you need MPR
ONIS 2.5 Free Edition is a Windows viewer from DigitalCore. It reads DICOM files from a folder, a CD or DVD, or a DICOM server, and it offers a single oblique MPR and MIP volume rendering, plus measurement and annotation tools. It is shareware (conditionally free): the Free Edition keeps a local database of only 15 patients, supports one monitor and cannot load extra plugins. Official system requirements list Windows XP SP3, Vista, 7, 8 and Windows Server, not Windows 10 or 11, and the 2.x line is no longer developed. Test it before relying on it.
It has no dental tools such as panoramic reconstruction, nerve canal marking or implant planning. DigitalCore’s newer ONIS Viewer 3.0 is a separate paid product.
DicomWorks: anonymise and export
DicomWorks is freeware created by two French radiologists. It opens DICOM CDs and folders, anonymises studies, and exports images to JPEG, BMP or AVI or straight into PowerPoint. It is closed source, and the last public build is 1.3.5b. The official website has shown a temporary page since 2011. It has no 3D and no MPR, and the authors do not claim regulatory clearance. It is most useful as a small anonymiser for teaching images; for everyday CBCT work, a maintained viewer is the better tool.
Opening a dental CBCT disc on Windows
- Look for a DICOMDIR file. A disc with a DICOMDIR index lets the viewer build a patient and study list automatically. If there is no index, open the folder of DICOM files directly.
- Check for a bundled viewer. Many CBCT discs include the manufacturer’s viewer that starts from the disc. It is often the one that shows panoramic and cross-sectional views correctly.
- Use a general viewer for slices. Open the same data in MicroDicom or ONIS to scroll through axial slices, change the window level and measure distances.
- Do not diagnose from a free viewer. For treatment planning use the software your clinic is licensed for.
- Anonymise before sharing. If you send images to a colleague or a student, remove the patient’s name and ID first. MicroDicom and DicomWorks both offer anonymisation.
Limitations
- Free viewers show images; they are not certified diagnostic workstations. MicroDicom says so explicitly.
- None of the options here has panoramic curve reconstruction, nerve tracing or implant planning.
- Licence terms differ: MicroDicom is free for non-commercial use only, and ONIS is a limited edition of a paid product.
- Old programs may not run on a locked-down clinic PC, and they will not receive security updates.
Which one should you use
- Student or teacher: MicroDicom for viewing and exporting; DicomWorks to anonymise teaching cases.
- Clinic IT: Weasis if you want open source with active development; test with real discs first.
- Need MPR on a Windows PC: ONIS 2.5 Free Edition, after testing.
- Mac user: see the HorliX page or the full list of free dental DICOM viewers.
FAQ
What is the best free DICOM viewer for Windows 11?
Among the viewers covered here, MicroDicom is the only one whose official site lists Windows 11, and it is free for non-commercial use. Weasis is a maintained open-source alternative.
Is there a free DICOM viewer for Windows 10?
Yes. MicroDicom lists Windows 10 and 11 as supported, and Weasis has a Windows distribution. DicomWorks and ONIS may start, but their vendors do not list Windows 10.
Can I use a DICOM viewer on Windows 7?
MicroDicom lists Windows 7, and ONIS 2.5 Free Edition lists it as well. Windows 7 no longer receives security updates, so keep such a PC off the clinic network.
Is DicomWorks free?
Yes. The authors describe it as freeware, not shareware. It is legacy software with no updates since 2011.
Do I need to install anything to view a DICOM CD?
Not always. MicroDicom offers a portable ZIP, and many CBCT discs contain their own viewer. Otherwise install a general viewer and open the DICOMDIR file.
Is the ONIS DICOM viewer free?
The ONIS 2.5 Free Edition is shareware (conditionally free), limited to 15 patients and one monitor.
Last updated: 11 October 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.
