DICOM viewer online — free, private, no upload

DICOM (.dcm) is the standard file format for medical imaging: one file holds the image pixels from a CT, MRI, X-ray or ultrasound scan together with dozens of metadata tags — patient identifiers, study and series descriptions, modality, and the imaging parameters. Scanners, PACS systems and hospital CDs all produce it. Files are often delivered without any file extension; this viewer does not rely on one.

Right here: drag the whole study folder onto the box above (or click "Choose a folder"). Every file is parsed in your browser tab and grouped into series — click a series, then scroll the mouse wheel on the image to step through slices, exactly like a desktop viewer. No PACS workstation, no RadiAnt or MicroDicom install, no account, no upload.

Drag on the image with the left mouse button: horizontal movement changes the window width (contrast), vertical movement changes the window center (brightness) — the same gesture every desktop DICOM viewer uses. The buttons above the image jump to the standard presets (Soft tissue, Lung, Bone, Brain) and "File default" restores the values the scanner saved. The current WC/WW values are always shown in the bottom-right corner; double-click the image to reset window and zoom.

Yes — by construction, which matters for patient data. The file is read and rendered entirely by JavaScript running in your browser; it is never transmitted. You can verify this yourself: open your browser's developer tools (Network tab), load a file, and watch — no file bytes are sent anywhere. The only requests this site makes are page loads, an anonymous usage counter (counts only, never content), and the one-time download of the open-source parsing library. Details in the privacy policy.

Two common cases are called out explicitly instead of failing silently: the file's pixels are stored compressed (JPEG or RLE transfer syntax — common from hospital PACS exports), or the file uses a YBR color space. In both cases the viewer says so and still shows the complete metadata. Uncompressed grayscale (MONOCHROME1/2 with windowing), RGB and palette-color images render directly.

Yes — that's the normal case. Drop a whole folder: files are grouped by series and sorted by the scanner's own slice order (Instance Number, with slice position as fallback). Scroll, use the slider, the arrow keys or the buttons to move through the stack. Multi-frame files (cine loops, whole series in one file) appear as slices of the same stack.

No. DCMView is a file-format utility for viewing and inspecting DICOM files; it is not a medical device and is not intended for diagnostic use, measurement, or treatment decisions. Always review clinical images on a regulated diagnostic workstation.

Yes — exports are the paid tier: any slice saves as PNG or JPG (exactly as windowed on screen) or as a one-page PDF, and the full series merges into one PDF report with a cover page. A single $9.99 lifetime license unlocks every export format. The viewer itself — folders, slices, windowing, zoom, metadata — is free and unlimited. One-click anonymization (strip identifying tags) is in active development. Everything, including the PDF, is produced locally in your browser.

Free forever: the whole viewer — open study folders, scroll slices, window/level, zoom, and the full metadata table, with no account and no upload. The one-time $9.99 license unlocks exports: any slice as PNG/JPG or one-page PDF, and the full-series PDF report with a cover page. Pay once — it's a lifetime license, not a subscription.

Your key is shown on your Gumroad receipt, emailed to you right after checkout — search your inbox for "Gumroad" and open the receipt to copy it. Then click "Enter license key" in the top navigation to re-activate PDF report export.