What it opens
Drag to pan, scroll or pinch to zoom, double-click to zoom in; the + and − keys work too. With a pixel size in the file, a scale bar follows the zoom. Save view as PNG keeps what is on screen.
Why most online viewers show a 16-bit TIFF as black
Microscope cameras record 12, 14 or 16 bits per pixel, but a screen shows 8. A viewer that maps 0–65,535 straight onto 0–255 squeezes a typical fluorescence image, whose signal sits between a few hundred and a few thousand, into the bottom few grey levels: black. This viewer sets each channel's display range from the 0.1st and 99.9th percentiles of its data (the same idea as Fiji's Auto button), and you can type exact minimum and maximum values or reset to the full range. That changes only what you see, never the file.
What it does not open
- JPEG 2000 SVS (Aperio compression 33003/33005), JPEG XR and JPEG XL cannot be decoded in a browser without WebAssembly, which this page does not load.
- Not TIFF-based: CZI, ND2, LIF, MRXS, VSI, IMS, OIB/OIR and DICOM need a desktop reader. NDPI is TIFF-like but stores each level as one huge JPEG, too large for a browser tab.
- OME-TIFF with several series shows the first series.
- No measurements, annotations or analysis: it is a viewer.
For those formats, and for measuring, annotating and counting cells on your own images, SlideScope opens 34 microscope and slide-scanner formats on Windows and Mac. SlideScope, the desktop microscopy app made by the same team, is a paid app with a free sample library (every tool) and a 3-day free trial for your own images. Free alternatives: Fiji (Bio-Formats) and QuPath.
How it opens a file without uploading it
When you choose a file, the browser hands this page a handle to it on your disk. The page reads only the bytes it needs: the TIFF directory first, then the tiles for the part of the image on screen, and decodes them in the page with an open-source TIFF reader (geotiff). Nothing is sent to a server, so unpublished data and slides with patient labels stay on your computer, and multi-gigabyte slides open in seconds because they are never copied anywhere. Close the tab and the file is gone from the page.
The page loads its own scripts from slidescope.science and the site's privacy-respecting page-view counter; neither ever sees your image. Open-source licences: image-tools-vendor.LICENSE.txt.
Questions
How can I view a TIFF file online without uploading it?
Open it in this page: the browser reads the file from your disk and draws it in the page, and nothing is sent to a server. Most other online TIFF viewers upload the file first.
Why does my TIFF look black or completely white?
It is almost always a 16-bit image whose values use only a small part of the 0–65,535 range. Auto contrast stretches the actual range of the data to the screen; set the minimum and maximum by hand for comparable images.
Can it open very large TIFF files?
Yes, if the file is tiled and has a pyramid (whole-slide images, pyramidal OME-TIFF, BigTIFF): only the tiles on screen are read, so multi-gigabyte slides open quickly. A large image without a pyramid can be explored by zooming and panning, but not shown whole.
Can it open multi-page TIFFs and Z stacks?
Yes. Pages, Z planes and time points get sliders; OME-TIFF and ImageJ hyperstacks are read as channels, Z and time.
Does it work on a Mac or an iPhone?
It runs in any current browser, including Safari on macOS and iOS. Safari can show simple TIFFs by itself, but not 16-bit, multichannel or pyramidal ones.
Is this TIFF viewer free?
Yes, it is free and needs no account. SlideScope, the desktop microscopy app made by the same team, is a paid app with a free sample library (every tool) and a 3-day free trial for your own images.
Need more than a browser can do?
SlideScope opens 34 microscope and slide-scanner formats on Windows and Mac, CZI, ND2, LIF, MRXS and JPEG 2000 SVS among them, with measuring, annotations, cell counting and full-resolution OME-TIFF export. Try every tool free on the built-in samples, then open your own images with the 3-day free trial. Already decided? Subscribe now.