ScreenshotTool is a desktop screenshot annotation app for macOS, Windows and Linux. Open an image or paste one from the clipboard, mark it up with pens, highlighters, arrows, text and callouts, then copy the result, save it as an image, or save it as a project you can keep editing.
It's free software (GPL v2 or later). On macOS it's a native AppKit app; on Windows, Linux and the BSDs it's built with GNUstep, and the GNUstep theme decides how it looks.
Get the latest version from the Releases page:
| Platform | Download | Requires |
|---|---|---|
| macOS | ScreenshotTool-<version>-macOS.dmg (Apple silicon and Intel) |
macOS 12 or later |
| Windows | ScreenshotTool-<version>-win64.msi, or ScreenshotTool-<version>-win64-portable.zip to run without installing |
64-bit Windows 11 (Windows 10 1809 or later should work, but is untested) |
| Linux | ScreenshotTool-<version>-x86_64.AppImage |
x86_64, glibc 2.38 or later (Ubuntu 24.04, Debian 13, Fedora 39 or later) |
SHA256SUMS on each release lists the files' checksums. Once installed, the app checks for
updates itself (Check for Updates…).
The release builds aren't signed with a paid developer certificate yet, so macOS and Windows warn you the first time. The steps to get past that are below.
Open the DMG and drag ScreenshotTool to Applications. The first time you open it, macOS says it can't verify the app: click Done, then Open Anyway in System Settings → Privacy & Security. Or, in Terminal:
xattr -dr com.apple.quarantine /Applications/ScreenshotTool.appThe DMG includes these steps as "Opening an unsigned app.txt".
Run the MSI. It installs for your user only, in %LOCALAPPDATA%\ScreenshotTool (about 85 MB),
without asking for an administrator. There's no wizard, just a progress box; then
ScreenshotTool is in the Start menu (there's no desktop shortcut). Your browser may warn that the
file isn't commonly downloaded, and on a new Windows 11 PC, Smart App Control may block an
unsigned installer. To check the download, compare Get-FileHash .\ScreenshotTool-<version>-win64.msi
with SHA256SUMS (it prints the hash in capitals). Uninstall it from Settings → Apps →
Installed apps; your settings stay in %USERPROFILE%\GNUstep\Defaults.
Or unzip the portable build anywhere and run ScreenshotTool.exe from the unzipped folder.
If you installed v0.1.0 or a v0.1.1 release candidate before rc4, download and run the new MSI by hand once: those versions' Check for Updates can't install updates on Windows. The MSI upgrades the existing installation in place, and later updates install from inside the app.
Take Screenshot uses Windows' screen-snip overlay (the Snipping Tool, or Snip & Sketch on Windows 10).
Install the AppImage with a desktop entry and icon, and keep it updating:
curl -fsSL https://raw.githubusercontent.com/danjboyd/ScreenshotTool/main/scripts/install_appimage.sh | bashThat puts it in ~/Applications/ScreenshotTool.AppImage. To remove it, run the same command
with bash -s -- --uninstall in place of bash; --channel prerelease installs release
candidates instead. The script needs curl, and jq or
python3. If you installed v0.1.0 or a v0.1.1 release candidate before rc4, run it again once: those
versions can't download updates themselves.
You can also download the AppImage, chmod +x it and run it directly. AppImages need FUSE's
fusermount3 (the fuse3 package, standard on desktop installs; libfuse2 isn't needed), or
run it with --appimage-extract-and-run. Under GNOME it uses the bundled
Adwaita theme; elsewhere it uses
GNUstep's default theme, with the menus in the window. Shortcuts use Ctrl on every desktop.
- Pen, highlighter, arrow, rectangle, text, numbered step, redact, select and eraser tools; a selected rectangle or redaction resizes by its corner handles, steps number themselves 1, 2, 3…, and a redaction pixelates the image under it (not the annotations over it). A project file keeps the original image so it stays editable, redactions included: share the saved image, not the project, when something must stay hidden. Pen, highlighter and text colours and widths are set from each tool's popover (double-click its toolbar button) and remembered as defaults.
- Text labels with a text bar for font, size, style and alignment; turn on Callout to make a label a callout: a filled box with bold text and a draggable pointer.
- Select, move and delete annotations; undo and redo every change from the toolbar or the Edit menu.
- Paste as New Image from the clipboard; Copy puts the annotated image (or the selection) on the clipboard with transparency intact.
- Share the annotated image (or the selection) from the toolbar, File > Share, the right-click menu or the bar next to a selection. macOS uses its own share menu. On Linux and Windows a sheet offers Email, Copy, Save a Copy, Show in Folder and Open With…, and, if rclone is installed, each of your remotes that can make links: the image is uploaded and its link copied.
- Save As writes a flattened PNG or TIFF. Save Project writes a
.screenshottoolfile with the original image and editable annotations, which Open and Open Recent read back. - Crop to Selection, Fit to Window, fixed zoom levels and Zoom In/Out.
- Drag the annotated image (or the selection) out of the Copy toolbar button into another app, a chat, a mail or a folder, as a PNG file named after the document (macOS and Linux).
- Custom actions: send the annotated image to a command of your own (an upload script, say) from the File menu, a toolbar button or the Share menus; see Custom actions.
- Standard controls throughout, so the GNUstep theme decides the look, including the toolbar, symbolic icons and the open and save dialogs.
- On macOS: a window per image (File > New Window, Open several at once); share the image from the toolbar or File > Share, drop images on a window to open them, and pinch or Command-scroll to zoom.
The native macOS app, shown at the top of this page marking up a settings page: numbered steps, a highlight, an arrow with a callout, and the email address and API key redacted. In dark mode, a tool's width and colour, from its colour button:
To regenerate these, run Tools/screenshots_macos.sh after scripts/build_cocoa.sh; it marks up
the shared sample (Tools/screenshot-sample/security-settings.png) and saves macos-text.png and
macos-dark-popover.png in build/screenshots-macos/. The terminal needs the Screen Recording
permission.
Under the WinUI theme, marking up a settings page: numbered steps, a highlight, an arrow with a callout, and the email address and API key redacted:
A tool's width and colour, from its colour button:
The app is built from standard controls, and the GNUstep theme decides how it looks. The same window, marking up a settings page: numbered steps, a highlight, an arrow with a callout, and the email address and API key redacted:
Under the Adwaita theme, as on a GNOME desktop: the toolbar sits in the header bar, and the menus are in its ☰ menu, with no menu bar row.
Under GNUstep's default theme, as on other desktops: the window manager's title bar, here with
GNUstep's own menus, a column of their own (defaults write NSGlobalDomain NSMenuInterfaceStyle NSNextStepInterfaceStyle; the AppImage puts them in the window).
A tool's width and colour, from its colour button.
To regenerate these images, run Tools/screenshots.sh after building the app. It opens the app on a
private display under both themes, marks up the shared sample
(Tools/screenshot-sample/security-settings.png), and saves each screen whole and cropped to its
window (*-window.png; under Adwaita without the theme's shadow, with transparent rounded
corners). The images here are adwaita-text-toolbar-window.png, default-text-toolbar-window.png
and adwaita-popover-window.png. The default theme's needs the release build's GNUstep backend,
whose patch keeps the toolbar showing after the window resizes (#60): point SCREENSHOT_APP at a
script that runs the built app on the release AppImage's runtime. SCREENSHOT_SAMPLE_DIR opens the
sample from a folder the title bar shows, such as ~/Pictures in a throwaway account.
Prerequisites: gnustep-make, gnustep-base, gnustep-gui, Clang, and
standard build tools.
git submodule update --init --recursive
make -j"$(nproc)"Notes:
- Open and save dialogs come from the GNUstep theme: under the Adwaita theme they're GNOME's own file chooser.
- A build from the tree uses the identifier
com.danboyd.screenshottool.dev, so its settings (~/GNUstep/Defaults/com.danboyd.screenshottool.dev.plist) are apart from an installed release's. The release build passesmake ST_DEV_BUILD=no.
scripts/build_cocoa.sh
scripts/smoke_macos_app.sh build/cocoa/ScreenshotTool.app
scripts/package_macos_dmg.sh build/cocoa/ScreenshotTool.appRequires Xcode 26 or its Command Line Tools; GNUstep isn't needed. The build compiles the
sources and copies the resources GNUmakefile lists, and produces a universal app signed ad
hoc. Set VERSION to stamp a version, or ARCHS=arm64 for a quicker one-architecture build.
Developer ID signing and notarization of the release DMG are planned (macos.md).
The MSI is built with GNUstep under MSYS2 CLANG64; see docs/Packaging.md.
./ScreenshotTool.app/ScreenshotTool ~/Pictures/your-image.pngBuild build/cocoa/ScreenshotTool.app with scripts/build_cocoa.sh, then
open build/cocoa/ScreenshotTool.app. scripts/smoke_macos_app.sh launches it with a sample
image and fails if the image doesn't open.
Runtime logs default to ~/.local/state/screenshottool/screenshottool.log on
GNUstep/Linux and ~/Library/Logs/ScreenshotTool/screenshottool.log on macOS.
Set SCREENSHOT_TOOL_LOG_PATH=/tmp/screenshottool.log to override the log
location.
Run the automated probes with:
make # the test bundle links libraries the app build produces
Tools/run_tests.shRun one class or test by name, or pass any xctest option (tests use the
tools-xctest submodule; run
git submodule update --init after cloning):
Tools/run_tests.sh FitViewportRoundingProbeTests
Tools/run_tests.sh FitViewportRoundingProbeTests/testFitTurnsOffAutohidingScrollers
Tools/run_tests.sh -test-iterations 20 TitleBarToolbarProbeTestsResults go to tests.log and, as JUnit XML, tests-junit.xml.
Most tests need a window server. Without a desktop session (as in CI), run them
under a virtual display with xvfb-run -a Tools/run_tests.sh; the script fails
if tests had to skip for lack of a display.
On macOS, Tools/run_tests_macos.sh builds the same tests against Apple's XCTest
(it needs Xcode) and runs them, optionally just the classes or tests you name.
The log goes to tests-macos.log.
Tools/screenshots.sh captures the main screens (empty window, Preferences,
an image, the text bar, the tool popover) under GNUstep's default theme and
Adwaita on a private virtual display, into screenshots/. It needs Xvfb,
xdotool, x11-utils and ImageMagick, plus GNOME Shell or Openbox for window
decorations. Your GNUstep defaults are left untouched. CI uploads the images
as the screenshots artifact.
Tools/check_wm_close.sh ScreenshotTool-x86_64.AppImage runs the AppImage as GNOME would, with
the Adwaita theme, under GNOME Shell or Mutter on a private virtual display. It checks that
the windows list WM_DELETE_WINDOW, and that asking the window manager to close Preferences,
then the main window (as Alt+F4 or the Overview does), closes them without the app being
killed. It needs Xvfb, xdotool, x11-utils, wmctrl and dbus-run-session. Your GNUstep
defaults are left untouched. CI runs it on each AppImage.
- Double-click a tool's toolbar button to open its popover.
- Right-click the image for what fits where you clicked: in a selection, Crop, Copy or Redact it;
on an annotation (which it selects), Edit Text, Duplicate, Bring to Front, Send to Back or
Delete; elsewhere, Copy Image, Paste as New Image, zooming, Save As and your custom actions.
Escclears the selection. - A finished selection gets a small bar next to it with Crop, Copy and Redact; Preferences > Appearance turns it off.
- Preferences hold the drawing and text defaults, the default save folder and whether the status bar is shown.
- While editing text,
Ctrl+ReturnorEscfinishes the label andReturnstarts a new line. - Save As flattens the annotations into the image; use Save Project to keep them editable.
- Open:
Ctrl+O - Save As:
Ctrl+S; Save Project:Ctrl+Shift+S - Undo / Redo:
Ctrl+Z/Ctrl+Shift+Z - Copy:
Ctrl+C; Paste as New Image:Ctrl+Shift+V - Crop to Selection:
Ctrl+K - Fit to Window:
Ctrl+0; 100%:Ctrl+1 - Zoom In / Out:
Ctrl+=/Ctrl+- - Preferences:
Ctrl+,
A custom action hands the annotated image (or the selection, when there is one, as Copy does) as a PNG to a command of your own and copies what it prints, so a personal workflow is one click. The app ships none: each is a JSON file in your actions folder, read at launch.
| Platform | Folder |
|---|---|
| Linux / BSD | ~/.config/screenshottool/actions/ (under $XDG_CONFIG_HOME) |
| Windows | %APPDATA%\ScreenshotTool\Actions\ |
| macOS | ~/Library/Application Support/ScreenshotTool/Actions/ |
$SCREENSHOT_TOOL_ACTIONS_DIR overrides the folder.
{ "title": "Send to Server",
"command": ["/usr/local/bin/upload", "--file", "{file}", "--host", "{choice}"],
"choices": ["/usr/local/bin/upload", "--list-hosts"],
"output": "clipboard",
"toolbar": true,
"icon": "send.png" }title(required): the name in the File menu and on the toolbar.command(required): the program, found onPATHor given as a path, and its arguments.{file}becomes the PNG's path and{choice}the choice picked.choices: a command whose output lines are the choices, listed in a submenu (and the toolbar button's arrow). The first is the default, which the button itself runs.output:clipboard(the default) copies what the command prints and says so;noneignores it.toolbar:trueadds a toolbar button.iconis an image file for it, relative to the actions folder or absolute. Under GNOME's header bar an action with an icon is an icon button, which leaves room for the window's title.timeout: seconds before the command is stopped (120 by default).
The command runs in the background, and the action is disabled while it runs or when no image is open. If it fails, an alert shows the last line of its error output. The PNG and its folder are removed when the command exits, so a command that hands the file to a process it leaves running must copy it first. A file that isn't a valid action is skipped, and the log says why. From the AppImage, commands get your own environment, without the AppImage's library paths.
- Contributing and development notes:
CONTRIBUTING.md - Workflow and testing handoff:
WORKFLOW.md - Packaging and releases:
docs/Packaging.md - Bugs, feature requests and planned work: GitHub Issues
GNU GPL v2 or later. See COPYING.