Image format
NII Sample Files
NIfTI (.nii) files are common in neuroimaging and scientific imaging workflows, storing volumetric image data with spatial metadata in a compact binary container. Use sample .nii files to validate volume readers, header parsing, coordinate transforms, and cross-tool compatibility in analysis and medical-imaging pipelines.
3 files
All to 50KB
SHA256 verified
Manifest included
Quick facts
Files first
NII Sample Files — Download
Starter file
DownloadAnatomical NIfTI Volume
Download FixtureFunctional NIfTI Volume
Download FixtureUse cases
NII Testing Workflows
Volume Preview and Structure Review
Open Format NIIFunctional and Resampled Volume Validation
Open Format NIICompare and decide
NII Format Comparisons
FAQ and reference
NII File FAQ
Checksum Verification
Use checksums to confirm file integrity after download.
shasum -a 256 your_file_name_here
# Compare output with SHA256 values listed above.Where is the machine-readable manifest?
Use the manifest when you need stable names, SHA256 values, and URLs for automation.
Use in code — curl, Python, Node, wget
Copy any snippet directly into scripts, test suites, or CI pipelines. All URLs are stable and publicly accessible with no auth required.
# Download nii_anatomical_volume_sample.nii
curl -L -o nii_anatomical_volume_sample.nii \
https://samplefile.com/samples/download/image/nii/nii_anatomical_volume_sample.nii/
# Or fetch a random NII file
curl -s "https://samplefile.com/samples/api/random?format=nii" | jq -r '.download_url'# Download nii_anatomical_volume_sample.nii
wget -O nii_anatomical_volume_sample.nii \
https://samplefile.com/samples/download/image/nii/nii_anatomical_volume_sample.nii/import requests
# Download a specific file
url = "https://samplefile.com/samples/download/image/nii/nii_anatomical_volume_sample.nii/"
resp = requests.get(url)
with open("nii_anatomical_volume_sample.nii", "wb") as f:
f.write(resp.content)
# Or fetch a random NII file via API
meta = requests.get("https://samplefile.com/samples/api/random?format=nii").json()
resp = requests.get(meta["download_url"])
with open(meta["name"], "wb") as f:
f.write(resp.content)// Download a specific file
const fs = require("fs");
const https = require("https");
const url = "https://samplefile.com/samples/download/image/nii/nii_anatomical_volume_sample.nii/";
https.get(url, (res) => {
res.pipe(fs.createWriteStream("nii_anatomical_volume_sample.nii"));
});
// Or fetch a random NII via the API
const meta = await fetch("https://samplefile.com/samples/api/random?format=nii").then(r => r.json());
const file = await fetch(meta.download_url);
// use file.arrayBuffer(), file.body, etc.# Random NII file (JSON response)
GET https://samplefile.com/samples/api/random?format=nii
# All NII files
GET https://samplefile.com/samples/api/files?format=nii
# Manifest with SHA256 checksums
GET https://samplefile.com/samples/image/nii/manifest.json
# Response includes: name, size_bytes, mime_type, sha256, download_urlValidation Methodology
- Validate MIME sniffing against extension and file signatures.
- Test transparency, color profile, and resize pipelines.
- Benchmark decode speed and memory use for larger dimensions.
Fixture Matrix
Use the curated NII matrix to choose the right clean, edge-case, and broken fixtures for this format.
Open Matrix