How to view a .CZI file online
No app, no account, no upload.
Open your .CZI
Drag a .CZI file from your scanner, camera or archive onto the viewer, or choose it from your device. It's decoded right here.
View and inspect
Flip through the pages of a multi-page file, zoom into fine detail, and read its compression, color and print-resolution details.
Save a copy
Export the page you're viewing as PNG, JPG or WEBP that opens on any phone or computer.
What is a .CZI file?
Everything worth knowing about Carl Zeiss Image (ZISRAW container).
A CZI file is a microscopy image saved by ZEISS ZEN acquisition software. It stores multiple channels, Z-stacks, time points, and tile scenes in one container, so ordinary image editors cannot open it. Open it free with ZEISS ZEN lite or Fiji/ImageJ (Bio-Formats plugin). To share a single channel or slice, export to TIFF or PNG from those tools.
Programs that open .CZI files
- Windows
- Fiji / ImageJ (Bio-Formats), QuPath, ZEISS ZEN lite
- macOS
- Fiji / ImageJ (Bio-Formats), QuPath
- Linux
- Fiji / ImageJ (Bio-Formats), napari (with bioio/aicsimageio)
| Full name | Carl Zeiss Image (ZISRAW container) |
|---|---|
| Developer | Carl Zeiss Microscopy GmbH |
| First released | 2011 (with ZEISS ZEN imaging software) |
| Category | Images |
| MIME type | image/czi |
| Signature | 5A 49 53 52 41 57 46 49 4C 45 ("ZISRAWFILE" - file-header segment identifier) |
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Frequently asked questions
Is my .CZI file uploaded to a server?
No. Your .CZI file is decoded with JavaScript and WebAssembly. The decoders are downloaded once from a public CDN.
How do I see the other pages of a TIFF?
Use the arrows above the image, the page thumbnails in the side panel, or the [ and ] keys. Every page can be saved separately as PNG or JPG.
Why do some TIFF tags look like numbers?
Tags are stored as raw values. We translate the common ones (compression, color mode, resolution, orientation) and list the rest exactly as they appear in the file.
Can I view GeoTIFF or GeoJP2 maps?
We show the image and tell you it's georeferenced. To see it on a map with coordinates, open it in our Map Viewer.
Is my 16-bit or HDR image shown accurately?
Images with more than 8 bits per channel are scaled to 8 bits for display and export. The original precision is listed in the structure panel.
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