Online DICOM viewer
Free online DICOM viewer. Open .dcm files, whole series and zipped studies, adjust window and contrast, and export images. Nothing is uploaded.
What it does
Drop a DICOM file here and it opens. No account, no installer, no plugin — the viewer is a web page that reads the file directly from your disk and draws it on screen.
It handles what real studies actually look like: hundreds of slices spread across several series, files with no extension, and the whole thing zipped into one archive. You can step through the images, zoom in, rotate, and adjust the window the same way viewing software in a hospital does.
Series and study navigation
Switch between studies and series and step through every image or frame with the arrows or the keyboard.
Window, brightness and contrast
Adjust window width and level directly, or let the viewer pick a window that fits the data in the file.
Zoom, pan and rotate
Scroll to zoom, drag to move around and rotate in 90° steps. One button puts everything back.
Export what you see
Save the current image as a PNG, exactly as it appears with your adjustments applied.
How to use it
Add your files
Drag in a .dcm file, a folder of images or a ZIP of the study.
Choose the series
If the study has several series, pick the one you want to look at.
Adjust the image
Use window and contrast until the structures you care about are visible.
Export or continue
Save the image, or send the study on to the converter or anonymiser.
When people use it
Checking the CD from the hospital
Confirm the disc actually contains your images before an appointment.
Looking at a scan on a computer with no software
A borrowed laptop, a work machine you cannot install on, or a Chromebook.
Picking the right slice to share
Step through the series, find the image that matters and export just that one.
Supported files
- Uncompressed DICOM (implicit and explicit VR, little and big endian)
- RLE lossless compression
- JPEG baseline and extended, decoded by your browser
- Files with a .dcm extension, and DICOM files with no extension at all
- ZIP archives containing a whole study or several series
Limitations
- JPEG Lossless, JPEG-LS, JPEG 2000 and deflated transfer syntaxes are not decoded — they need heavy codecs we deliberately do not ship. You will get a clear message instead of a blank screen.
- This is a technical tool. It does not read your scan, does not look for findings and does not produce any diagnosis.
- Very large studies of several hundred megabytes may be slow, because all the work happens on your own machine.
Privacy and security
Processed in your browser — nothing is uploaded
Your files never leave your device. Everything runs inside your browser using JavaScript — there is no upload, no server copy and no queue.
Because nothing is uploaded, there is nothing for us to store or delete. Closing the tab removes the files from memory.
We never put file names, patient identifiers or metadata values into analytics or logs. Product events only count how many files were opened.
If you later choose the paid AI explanation, that is a separate, explicit step: you decide which files to attach and nothing is sent until you confirm.
Frequently asked questions
Does the viewer upload my scan?
No. The file is read by JavaScript in your browser and drawn on a canvas. It never travels over the network.
Can it open a whole study at once?
Yes. Drop in a ZIP or select all the files, and the viewer groups them into studies and series automatically.
Why is my image very dark or completely white?
The window is wrong for that data. Press the auto-window button, or move the window level and width sliders until the anatomy appears.
My file will not open. Why?
Either it is not a DICOM file, it is damaged, or it uses a compression the browser cannot decode such as JPEG 2000. The viewer tells you which of those it is.
Can I see the patient details?
The viewer shows the study and series description. For every stored field, use the metadata viewer.