View NRRD files in your browser
3D Slicer's own format for scans and labels. Open a volume right here and step through it in every plane, with nothing to install. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your scan opens slice by slice, with its series or planes beside it, what the scanner says in its corners and the patient's sides at its edges.
- Every series in order through the body • The wheel steps through it
- Window and level • Drag it, or pick CT's presets
- Measure lengths, angles and areas in millimeters
- Export • PNG, JPEG, MP4, or the files without patient data
About NRRD
NRRD, Nearly Raw Raster Data, comes from Gordon Kindlmann's Teem libraries. 3D Slicer saves its volumes and segmentations in it, and research tools from ITK to Python's pynrrd read it.
A NRRD starts with a short text header: the voxels' type and size, where the volume sits in space and how its data is packed, raw, gzipped or written out as text. The data follows in the same file, or sits in another one that an .nhdr header names.
Filepeek reads the header and the voxels in your browser and cuts the volume into axial, coronal and sagittal slices, with the patient's sides at the edges. Step through with the wheel or the arrow keys, set the window and level, measure in millimeters, read the header, and save a slice as PNG or JPEG or a plane as MP4.
Nearly Raw Raster Data
.nrrd • .nhdr
Format
- MIME type
- application/x-nrrd
- Made by
- Gordon Kindlmann, for Teem
Inside the file
- Header
- Text, a field a line
- Voxels
- 8 to 64 bit, integer or float
- Packing
- Raw, gzipped or as text
- Data
- In the file, or beside it for .nhdr
- Space
- Where each voxel sits, in millimeters
Opens in every browser
Browsers download NRRD files. Filepeek opens them in Chrome, Edge, Firefox and Safari.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Questions
How do I open an .nhdr file?
Drop the .nhdr together with the data file it names, often a .raw or .raw.gz. Filepeek finds it beside the header.
Which planes can I see?
All three: axial, coronal and sagittal, each listed beside the image. Pick one and step through its slices with the wheel, the arrow keys or the slider.
Can I save a slice as a picture?
Yes. Choose Export to save the slice on show as PNG or JPEG, as it looks with the window you set, or a whole plane as an MP4.
Is my scan uploaded?
No. It opens inside your browser and never leaves your device.