Changelog

2026-09-28

• OME-Zarr version 0.6 files open. Version 0.6 is the newest version of the OME-Zarr format. Files saved in it now open like any other: from a web link, a folder on your computer or a zip file, with time-lapses, well plates and segmentation labels. Getting started
• Zip files open as they are. To send a dataset as one file, right-click its folder and choose Compress on a Mac, or Send to › Compressed (zipped) folder on Windows. The viewer opens that zip directly, with nothing to unpack. Local files
• A clearer message when a file cannot open. If a file uses an OME-Zarr version the viewer does not support yet, the message now says which version it is and what you can do.

2026-09-21

• Time-lapse playback. A Play button under the time slider, and Space to toggle it. Frames advance one at a time, each shown complete, at four per second by default. Dragging the slider pauses. Embedding
• Embed code from the toolbar. The new Embed button turns the current view into an HTML element or a MyST directive, ready to copy, with an autoplay option for time-lapses. Local files are refused with a reason. Embedding
• Embed controls read on a white page. theme="light" now styles the time slider, the channel panel and the colour picker, not only the buttons. The range tracks lost their grey bar on white. Clicking a channel's caret closes its open picker instead of reopening it.
• autoplay and fps for embeds. A time-lapse figure in an article can start on its own and pauses while scrolled out of view. Embedding

2026-09-19

• The embed works inside a shadow root. MyST and Curvenote sites, Elemental Microscopy among them, isolate each widget in a shadow DOM, where the viewer used to fail with "Container not found". It now finds its own canvas and its own stylesheet wherever it is mounted. Embedding
• A widget module for MyST articles. embed/v1/widget.mjs follows the any:bundle and anywidget contract, so one directive embeds the viewer with the same attributes as the HTML element. Embedding
• grayscale and invert attributes. The BW and INV toggles of the viewer, for embeds. Inverted nuclei on white look like a printed figure. Embedding

2026-09-18

• The embed opens the series you asked for. On a multi-image store, image="1" and up failed with "Failed to load image metadata" since May, when the viewer started loading only the first series at open time. The embed now asks for the series the same way the viewer does when you navigate to it. Embeds of single-image stores were never affected. Embedding

2026-09-02

• Open a dataset packed into a single file. Drop an .ozx or a .zip onto the viewer, or pick one with Choose Zipped Dataset. The viewer reads pieces of the archive as it needs them, so nothing is unpacked and a large dataset opens as fast as a folder. Local Files
• Local data now opens in Safari and Firefox. A zipped dataset is one file, and every browser can read a file. Dataset folders still need Chrome or Edge, and the viewer now says only that rather than telling those browsers they cannot open local data at all. Local Files
• Double-click an .ozx to open it. The installed app now registers the extension, so a dataset opens from Finder or Explorer without finding a browser window first. Chrome and Edge, once installed. .zip is deliberately not registered. Local Files
• Recent zipped datasets reopen as files, not folders. Clicking one used to ask for a directory, which is not a thing you have when your dataset is a single file. In Chrome and Edge it now asks only for permission; elsewhere it asks for the file. Either way you land back on the same image, annotations and all. Local Files
• The drop overlay promises only what your browser can do. It said "Drop ZARR folder to open" everywhere, Safari included, where a dropped folder cannot be read at all.
• A plate that lists wells it does not hold says so. It used to report that the viewer had failed to read a dataset, which sent people to file a bug about a truncated copy. It now names the count it found and suggests checking the copy.

2026-09-01

• Drop a folder onto the viewer, not just the start screen. No going back to close what you have open first. Drag a dataset onto the viewer and it opens there. Local Files
• A drop that would replace your image asks first. It names what you dropped and what is open, so a stray drag does not cost you your place.
• Edits are no longer lost when you switch images. A change made just before opening something else could be dropped before it saved. Closing the tab was always safe. Switching was not. It is now.

2026-08-31

• Open a folder of datasets and pick one. When the folder you open holds datasets rather than being one, the viewer lists what it found and opens whichever you click. No trip back to the file manager to drag the same data again, one level down. Local Files
• It looks inside a folder instead of reading its name. A dataset is recognised by what it contains, so folders named for a codec, a condition, or nothing in particular are found just as readily as ones named something.zarr.
• When the viewer cannot read a dataset, it says so. Instead of suggesting your folder is misnamed, it tells you the problem is on our side, and gives you a way to say which tool wrote the data so we can fix the reader. Local Files

2026-08-22

• Label order sticks now. Drag a mask up or down, and it comes back where you left it. Order is also draw order, so this decides which compartment paints over which. Labels
• Labels you linked yourself keep their order too. Re-linked masks used to come back in the order the folder declared them, whatever you had chosen. Saves made before this fix are read correctly, so nothing needs re-saving.

2026-08-21

• Shared links now carry the whole view. What you see is what they see. Sharing Views
• Opening a link keeps your own settings. It changes only what the link names. Sharing Views
• Links no longer switch on your own labels. Labels built into a dataset travel with the link. Ones you added yourself stay yours, and the viewer says when a link had one. Labels
• Z-projection travels in the link, over the whole stack or a slab of it. Z-Projection
• Fixed the mean projection. Deep stacks came out too dark. Worth re-checking anything you measured from one. Z-Projection
• Faster Z-projection on deep stacks, and easier on memory.
• New custom background colour picker. Black, white, greys, or any colour you like.
• Brightfield images now open on a white background by default.
• A link naming some channels no longer blanks the others. They keep the settings you already had. Channels

2026-08-14

• Install the viewer like an app. Install it from your browser and it opens from the dock or start menu, in its own window, with no address bar and no tab to lose. Installing and Offline
• It works with no connection. The viewer's own program files are cached on first visit, so it starts and runs offline. Local files open on a plane or behind a firewall exactly as they do online. Remote URLs still need a network, for obvious reasons. Installing and Offline
• Your images are never cached. Only the program is. Image data is read on demand and never written to the offline cache, by design.

2026-08-11

• Inverted display got consistent rules. INV swaps white and black, and only those: every other channel colour keeps its hue. The canvas background follows the toggle, and channel swatches show the colour that actually lands on the page. Channels
• Contour rendering is much faster on chunked masks. Label chunks are now read aligned and cached, so outlining no longer multiplies decompression work. Toggling contour, fill or colours reuses cached data instead of re-reading it. Labels
• Improved Contour rendering for large images when zoomed out. The black outline fades into the fill where objects get too small to hold it, so a plate overview shows coloured objects instead of a black mass.
• Clear All Data now clears everything, including annotation templates and UI preferences, and the confirmation lists exactly what goes before you commit.

2026-08-10

• Analytics and phenotyping. Attach a measurements table to a segmentation, colour objects by any column, filter by value, then group them into named phenotypes. Analytics and Phenotyping
• Annotations and templates. Draw and measure regions in real units. Classify them with reusable colour, class and shortcut templates, and export as CSV or GeoJSON. Annotations · Annotation Templates
• Documentation. Fourteen guides with screenshots, plus a published spec for the analytics data format so other tools can emit something the viewer reads. Guides · Analytics Data Format