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HomeFormats.NIIID

What is a .NII file?

NII is a NIfTI neuroimaging file, used in brain MRI research.

Did you know
  • NIfTI was created in the early 2000s to standardise brain-scan data for researchers.
  • NIfTI was devised by a US National Institutes of Health working group as a cleaner successor to the older ANALYZE 7.5 format.
  • Unlike ANALYZE, which split a scan across separate header and image files, a single .nii file holds both the header and the voxel data together.
What Analyser reads
Open scientific, medical and engineering files: DICOM scans, NIfTI brain volumes, Garmin FIT/TCX activities, FITS astronomy frames, FASTA/FASTQ sequences, chemistry structures (MOL/SDF/MOL2/CIF/XYZ), Gerber/Excellon PCB data, SPICE netlists, EDF/BDF biosignals, JCAMP-DX spectra, SPSS/Stata/SAS datasets and VTK/ParaView meshes - metadata extracted entirely in-browser.
Depth of analysis
.NII is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
Open a .NII file
Drag a .NII file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.
Related formats
.DCM · .DICOM · .FIT · .TCX · .FITS · .FTS · .FASTA · .FA · .FNA · .FAA · .FASTQ · .FQ · .MOL · .SDF · .MOL2 · .CIF · .MMCIF · .XYZ and more. See all supported file types.