Getting started
Cosmic Capture Kit is a one-shot capture tool. It does not sit on screen waiting for you. You press a key, it takes over the screen so you can pick what to capture, it hands you the result, and then it exits.
That is the whole shape of the app:
- You press your capture key.
- The capture overlay appears over a frozen picture of your screen.
- You pick a region, a window or a monitor, and take a screenshot, start a recording, or scan what is on screen.
- The preview editor opens with the result, so you can mark it up, cut it, and decide where it goes.
- You save, copy, share or upload, and the app closes.
Installing
macOS
Download the latest .dmg from the
releases page and
drag the app into Applications. macOS 13 or later.
There are two builds, one per processor. Take the aarch64 one for an Apple
Silicon Mac (M1 and later) and the x86_64 one for an Intel Mac. The Apple
menu's "About This Mac" names the chip if you are not sure.
Windows
Download the latest .msi from the
releases page and
run it. It installs for your user only, so there is no administrator prompt, and
it adds two Start Menu shortcuts: Cosmic Capture Kit, and Cosmic Capture Kit
Settings. Everything the app needs to record is installed with it.
The installer is not code-signed yet. On the first run Windows may show "Windows protected your PC". Click More info, then Run anyway.
Linux
The Linux app is free software. Download the latest .AppImage from the
releases page,
chmod +x it and run it. It carries its own ffmpeg and tesseract, so recording
and text detection work with nothing else installed, and it runs on glibc 2.34
or newer (Ubuntu 22.04, Mint 21, Pop!_OS 22.04, Debian 12 and anything newer).
There is a plain zip beside it if you would rather use your distribution's own
ffmpeg and tesseract.
You can also build it yourself, which is the route on architectures other than x86_64. DEVELOPERS.md has the exact commands for your distribution, including the packages to install first. COSMIC is the supported desktop today.
The first launch on macOS
macOS will not let any app read your screen until you say so, so the first launch opens a permissions window that lists what the app is asking for and whether it has it yet. The statuses update live as you grant them.
| Permission | Needed? | What it buys you |
|---|---|---|
| Screen Recording | Required | Without it every screenshot and recording comes out blank. macOS only applies this grant to the next launch, so relaunch the app after granting it. |
| Microphone | Optional | Records your voice into a video. Recording without your voice still works. |
| Notifications | Optional | Shows a banner when a capture is saved. Clicking the banner reveals the file in Finder. |
| Accessibility | Recommended | Lets Capture Active Window and Capture Active Monitor target the window you are actually focused on, and capture it in its active appearance. Without it the app guesses from the window stacking order, which is usually right but can pick the wrong window. |
Only Screen Recording is required. You can skip the rest and the window will stop asking. If Screen Recording is missing, the window keeps coming back, because there is nothing useful the app can do without it.
Setting up your capture key
The app is meant to be launched from a key, not from an icon.
macOS and Windows
Both platforms run a small background helper that lives in the menu bar (macOS) or the notification area (Windows). It is what listens for your capture key, and it is on by default. You can turn it off in Settings, under General.
A fresh install ships with no capture key set. You choose your own in Settings, under Shortcuts, in the section called Global. There are seven of them, and every one is optional:
| Shortcut | What it does |
|---|---|
| Capture All In One | Opens the full picker, so you choose region, window or monitor |
| Capture Active Window | Captures the frontmost window straight away, with no picker |
| Capture Active Monitor | Captures the monitor under the pointer straight away, with no picker |
| Capture All In One (no editor) | The same picker, but the result is saved, copied and announced without the editor opening |
| Capture Active Window (no editor) | The same instant window capture, delivered without the editor |
| Capture Active Monitor (no editor) | The same instant monitor capture, delivered without the editor |
| Color Picker | Opens the colour picker, which reads a colour off the screen |
Linux
Your desktop owns the keys, so you add them there. Point a custom shortcut at the app with the command for the capture you want. On COSMIC that is Settings, then Keyboard, then Shortcuts, then Custom shortcuts.
| Command | A key that suits it |
|---|---|
cosmic-capture-kit capture --region |
Alt+Shift+1 |
cosmic-capture-kit capture --active-window |
Alt+Shift+2 |
cosmic-capture-kit capture --active-monitor |
Alt+Shift+3 |
cosmic-capture-kit color --picker |
Alt+Shift+C |
The Global tab in Settings shows the same list with the command for each one, so you can copy them from there instead of typing them.
Add --skip-editor to any of them for a variant that skips the editor. The
capture is still saved, copied to the clipboard and announced by a
notification, and clicking that notification opens the folder with the file
selected.
The command line page lists every command.
Opening settings
Settings is a normal window, and it does not take a capture.
- macOS and Windows: use the menu bar or notification area icon, or the Cosmic Capture Kit Settings shortcut in the Start Menu on Windows.
- Any platform: run
cosmic-capture-kit settings.
Everything you change is saved as you change it. There is no Apply button.
Start there and set your save folders before your first capture, so you know where things are landing.
Where to next
- The capture overlay covers picking what to capture, recording, and the scanner.
- The preview editor covers marking up a capture and sending it somewhere.
- Settings walks through every option, page by page.