QuickLook on Windows: a tray previewer whose four install paths trade updates against Open/Save dialogs

A tray process that answers the space bar anywhere in Explorer

QuickLook is a background program, not a viewer you open by name. It starts with the machine, lives in the system tray, and answers the space bar inside File Explorer. Select a file, press space, and a preview window appears over whatever you were doing. Press space again or press `Esc` and it goes away.

The rest of the interaction is small, and worth knowing before you build a habit on it. Arrow keys page through the selected files without closing the window, so a folder of two hundred PNGs becomes a run of keypresses instead of two hundred double-clicks. You can drag a file straight out of the preview window and drop it somewhere else. Rendering is hardware accelerated and the window follows the Fluent Design System, a Windows shell convention rather than a theme setting you choose.

The reader this is for is narrow: someone working on Windows across mixed file types who wants a peek without launching whatever application owns each one. The README frames it as roughly ten seconds of double-click, app launch, view and close against one space press.

Four distributions, and the Open/Save dialog gap in the Store one

Four build paths ship, and they are not the same program in packaging terms.

The Microsoft Store build is recommended for most users because updates arrive on their own, the install is sandboxed, and setup is one click. The same card in the install table then warns about Open/Save dialog support. The comparison table further down is blunter about it, marking Open/Save dialogs as unavailable for the Store build and portable mode as unavailable too.

The installer from the GitHub releases page makes the opposite trade. It carries complete functionality, Open/Save dialog support and a portable option, while the auto-updates column gets a warning instead of a tick. The build with the most features is also the one you update by hand.

Scoop and nightly builds both keep dialog support. Scoop updates through the package manager, nightly does not, and the stability column rates nightly one notch below the other three.

The gap that matters for a rollout: no single build carries automatic updates, Open/Save dialog support, portable mode and the top stability rating together. Scoop gets the first two and drops portable mode. The installer gets the last two and loses automatic updates. Nightly keeps dialog support and portable mode but marks auto-updates with a warning and loses a stability point. Decide which of those four you cannot work without, because that is the axis the four packages actually differ on.

Installing from the Scoop extras bucket takes two commands

Command line users install through Scoop, which needs the extras bucket registered once:

scoop bucket add extras
scoop install quicklook

The first line adds a third-party bucket to Scoop's manifest sources. The second installs the `quicklook` package by that name. Once it finishes, the program runs on its own. There is no service to register and no enable step for you to perform; the five-step quick start in the README is install, it runs automatically, select a file, press space, preview shows up.

The other three routes have no commands attached to them at all. The Store build comes from the Microsoft Store listing. The installer and the nightly builds come from the GitHub releases page, the nightly under its own tag. Nothing on those pages is scripted here because nothing about them is scripted.

After any of the four, check which package actually landed.

Previews land in Explorer, open dialogs, Total Commander and cloud folders

File Explorer is only one of the surfaces. Four are named: Explorer itself, the system-wide Open/Save dialogs, third party file managers including Total Commander and xplorer², and cloud folders served by OneDrive and Dropbox.

Open/Save dialogs are what the Store build gives up according to the comparison table, so a reader who previews inside those dialogs cannot take the recommended package and expect the space bar to work there. That is a packaging decision, not a bug, and the comparison table makes it visible before you install rather than after.

OPTIONS.md sits at the repository root; read it to see which behaviours can be switched.

A hundred formats through a plugin boundary with no published interface

Format coverage is the headline claim, over a hundred types sorted into visual files, documents, developer files and media. The list mixes items with wildly different costs, which matters more than the count. JPEG and Markdown are cheap. PSD, AI, FBX, EPUB, CBZ, CBR, sheet music and RAR archives each need a decoder that has to be bundled, licensed or written. The documentation presents them as one flat list.

Extensibility is claimed in the same breath, with plugins named as the extension mechanism, and the source tree backs the claim at the structural level. A `QuickLook.Plugin` project and a `QuickLook.Common` project sit beside the main app, with `QuickLook.Native` for the interop layer.

The README's navigation links to an Extend section, which is the place to look for how plugins are added.

SUPPORTED_FORMATS.md at the root holds a separate format list, so the claims about what opens in a preview window live in two documents that can drift apart.

Appx and Installer are separate projects, not two flags on one binary

The repository layout explains the packaging better than the prose does. The root holds `QuickLook.slnx` as the solution file and six project directories: the main `QuickLook` application, `QuickLook.Appx` for the Microsoft Store package, `QuickLook.Installer` for the installer distribution, `QuickLook.Native` for native interop, and `QuickLook.Plugin` with `QuickLook.Common` on the plugin side.

Two packaging projects for two distribution channels is the clearest evidence that the Store build and the installer build are separate code paths.

Older tooling survives in the same root alongside the modern XAML. `QLPlugin.ico` is present, `.gitmodules` means parts of the build arrive as submodules, and `.appveyor.yml` points at AppVeyor for continuous integration. `CodeMaid.config` and `Settings.XamlStyler` are formatting settings for C# and XAML. Anyone who clones the repository and hits a submodule or build step failure has to read `Build/` and `Scripts/` to find out what the build expects.

The last push is 2026-09-29 while the release feed's latest tag reads 2024-12-06

Work on master is current. The last push landed on 2026-10-29 and the repository is not archived.

The release feed is where the picture gets strange. It carries a rolling `latest` tag dated 2024-12-06 next to numbered releases 4.5.0 from 2026-04-14 and 4.4.0 from 2026-01-08. The rolling tag is therefore older than two of the numbered releases it ought to sit ahead of. The releases page does not say which of these the Store package and the Scoop manifest actually resolve to, and the auto-updates column that marks Store and Scoop as automatic tells you something updates without telling you that it updates to the newest build.

Licence is GPL-3.0, with `LICENSE-GPL.txt` at the root. Anyone redistributing a modified build, including through a managed software catalogue, inherits the GPL-3.0 obligations attached to that redistribution. That is a statement of what the licence is, not a reading of what it requires of you.

PRIVACY.md and OPTIONS.md are both in the repository. What the tray process records, and what the options can switch off, are things you read rather than assume.

Editorial conclusion

QuickLook suits a Windows user who opens many file types from File Explorer and does not care how the program was installed. Skip it if previewing inside Open/Save dialogs is part of your day, because the Store build does not offer that, and stay off the nightly channel unless you can absorb an unstable build. Before putting it on a shared machine, open OPTIONS.md and PRIVACY.md yourself. Check which distribution you actually installed before anything else, because the four builds differ on auto-updates, dialog support and portable mode.

Frequently asked questions

Official sources

1. License: GPL-3.0
2. Project website
3. QL-Win/QuickLook on GitHub
4. README
5. Releases