SnipIT

A professional snipping tool for Windows 11 written in pure PowerShell 7.5+ on .NET 9. Hover-to-highlight smart capture, magnifier loupe, floating widget, system tray, chromeless Fluent preview with a full annotation editor — all in a single script with zero external dependencies and no admin elevation.

Features

Capture

• Smart capture — hover any window to highlight it and click to grab, or drag for a custom region. One overlay, two gestures, with a pixel-perfect magnifier loupe and live screen-coordinate readout.
• Full virtual-desktop capture spanning all monitors (handles negative-origin layouts).
• Active window capture — grabs the foreground window by its exact window rect.
• Per-monitor DPI aware — accurate capture at 100 % / 125 % / 150 % / 200 %.

Preview window

• Chromeless Fluent UI — WPF Fluent theme, Segoe Fluent Icons, draggable header, pin-on-top, resizable, maximizable.
• Zoom — Zoom In / Zoom Out / Fit-to-viewport buttons, Ctrl + +, Ctrl + -, Ctrl + 0, and Ctrl + mouse-wheel all work. Range 5 % – 1000 %. Live zoom indicator in the header.
• Pan (Hand) mode — the default when no annotation tool is selected: click and drag anywhere on the image to scroll a zoomed-in view. Cursor auto-switches between Hand and Cross.

Annotations

• Four annotation tools: Highlight, Rectangle, Arrow, Text
• Six-color palette (yellow / green / pink / blue / orange / red) with live in-place color updates — change color while typing a text annotation and the foreground swaps immediately
• Undo / Redo with full history (Ctrl+Z / Ctrl+Shift+Z)
• Right-click any annotation to change its color or delete it
• Clear all button to wipe the annotation layer
• Annotations are stored in image-pixel coordinates so they survive zoom and export cleanly

Output

• Copy to clipboard — flattened with all annotations baked in (Ctrl+C)
• Save as — PNG / JPG / BMP, default path ~\Pictures\Snips\snip-yyyyMMdd-HHmmss.png (Ctrl+S)
• New snip — close the preview and start a fresh capture (Ctrl+N)

System integration

• System tray with full menu (capture modes, open snips folder, about, uninstall, exit)
• Floating capture widget — auto-hiding top-center pill with Smart/Full/Window buttons
• Global hotkeys registered via RegisterHotKey on a hidden message-only form
• Single-instance enforced by a per-session named mutex; a second launch shows a friendly message instead of stacking up
• Self-installing: first launch copies itself to snipIT-Home/ next to the script, creates a Desktop shortcut, and adds an Auto-Start shortcut to shell:startup. No admin. No registry writes outside HKCU. No UAC prompts.

Hotkeys

Global

Hotkey	Action
Ctrl+Shift+S	Smart capture (hover-window or drag-region)
Ctrl+Shift+F	Full virtual-desktop capture
Ctrl+Shift+W	Active window capture
Esc / right-click	Cancel an active capture

Preview window

Hotkey	Action
Ctrl+C	Copy flattened image to clipboard
Ctrl+S	Save as PNG / JPG / BMP
Ctrl+N	New snip
Ctrl+Z / Ctrl+Shift+Z	Undo / Redo
Ctrl + + / Ctrl + -	Zoom in / out
Ctrl + 0	Reset zoom to 100 %
Ctrl + mouse-wheel	Zoom centered on cursor
Esc	Close preview

Install

1. Make sure you have PowerShell 7.5+ and Windows 11 (pwsh --version)
2. Download SnipIT.ps1
3. Double-click it (or run pwsh -Sta -File .\SnipIT.ps1)

On first run SnipIT silently:

• Copies itself to snipIT-Home\SnipIT.ps1 next to the source script
• Creates a Desktop shortcut
• Creates an Auto-Start shortcut in shell:startup (so it launches at login)
• Generates a SnipIT.ico on the fly
• Shows a tray balloon: "SnipIT installed. Press Ctrl+Shift+S to capture."

To uninstall: right-click the tray icon → Uninstall. Removes both shortcuts and the snipIT-Home folder.

Usage

After installation, SnipIT runs in the system tray. Press Ctrl+Shift+S, hover the window you want, click. The preview window opens with the captured image. From there:

• Annotate — click a tool, pick a color, drag on the image. Click the active tool again (or Esc) to return to pan mode.
• Zoom in to detail — Ctrl + mouse-wheel or the zoom buttons; then drag the image to pan around.
• Change an existing annotation — right-click it to pick a new color or delete it.
• Type a text annotation — click the Text tool, click on the image, type, click a different color mid-typing to re-color live, press Enter to commit (or click elsewhere). Escape discards.
• Copy or save — Ctrl+C / Ctrl+S, or the toolbar buttons.
• New snip — Ctrl+N or the toolbar button to close the preview and drop straight back into the capture overlay.

Architecture

Single file, organized into regions:

SnipIT.ps1
├── #region Core              ← pure logic, no UI/Win32 (testable cross-platform)
├── if ($CoreOnly) { return } ← unit-test gate
├── #region Bootstrap         ← STA self-relaunch, DPI, console hide, single-instance
├── #region PInvoke           ← Win32 signatures (RegisterHotKey, DWM, etc.)
├── #region Icon generation   ← Runtime .ico synthesis
├── #region First-Run Install ← Desktop + Startup shortcuts via WScript.Shell
├── #region Capture Core      ← GDI+ bitmap capture / clipboard / save dialog
├── #region Smart Overlay     ← WPF transparent overlay + hover + magnifier
├── #region Preview Window    ← Fluent preview + annotation editor
├── #region Capture Orchestration
├── #region Floating Widget   ← Auto-hiding top-center capsule
├── #region Tray + Hotkeys    ← NotifyIcon, ContextMenuStrip, RegisterHotKey
└── #region Main loop         ← WinForms message pump + cleanup

The Core region exports 10 pure functions: Get-DragRectangle, Test-IsClickVsDrag, Get-LoupeSourceRect, Get-LoupePosition, Get-DefaultSnipFilename, Get-ImageFormatNameFromPath, Test-CaptureRectValid, Get-CropBounds, Get-InstallPaths, Get-ShortcutArguments. None of them touch WPF, Win32, or the file system, so they run on Linux/macOS pwsh too.

Preview-window internals

The preview window's mouse interaction, zoom, text-editing and color-picking are all organized as named closures captured at window-creation time ($beginPan, $updatePan, $endPan, $beginDraw, $updateDraw, $finishDraw, $openText, $pickColor, $handleMouseDown, $setZoom, $zoomBy, $fitToViewport). The real WPF event handlers are one-line wrappers that compute mouse positions and delegate to these closures. This keeps the event handlers trivial and — more importantly — gives the test harness a way to drive every code path without synthesizing real MouseButtonEventArgs.

Show-PreviewWindow accepts an optional -TestAction [scriptblock] parameter that runs the callback during Loaded (while ShowDialog is blocking, so function-local variables stay alive) and then closes the window off-screen. The interactive harness uses this to run 42 end-to-end tests against a headless preview window.

Setting the environment variable SNIPIT_TEST_MODE=1 before dot-sourcing SnipIT.ps1 short-circuits the single-instance mutex, tray setup, hotkey registration and main loop, so a harness can load the functions without side effects.

Tests

82 tests total, two suites, both zero-dependency (no Pester):

# 40 pure-logic unit tests (runs on any platform with pwsh)
pwsh -NoProfile -File .\Test-SnipIT.ps1

# 42 interactive WPF tests against a real Show-PreviewWindow (Windows only)
pwsh -NoProfile -Sta -File .\Test-SnipIT-Interactive.ps1

Test-SnipIT.ps1 (40)

Covers rectangle math, click-vs-drag thresholding, loupe clamping for negative-origin multi-monitor setups, filename + image-format derivation, capture-rect validation, install-path computation, and shortcut argument formatting. Dot-sources SnipIT.ps1 -CoreOnly so only the pure functions load.

Test-SnipIT-Interactive.ps1 (42)

Drives a real off-screen preview window via -TestAction. Coverage:

• Zoom — SetZoom, ZoomBy, compounded zoom, clamps (0.05 / 10), ZoomText update, FitToViewport
• Pan — default Hand cursor, drag → Scroller offset, EndPan cursor restore, no-op when not panning
• Tool selection — Highlight / Rect / Text interlock, cursor switching
• Drawing — highlight / rect / arrow with coord mapping at 1× and 2× zoom, short-arrow auto-discard
• Colors — all six palette entries applied to new annotations via ActiveColor and via PickColor
• Undo / Redo
• Hit test — Find-AnnotationAt topmost wins, outside returns -1
• Flattening — Get-FlattenedBitmap dimensions and type
• Full click dispatch via HandleMouseDown — pan / draft / text / out-of-bounds / editing-text branches
• Text tool — OpenText creates a TextBox; empty commit discards; typed commit appends annotation; live PickColor foreground swap during editing; Render-Annotations applies annotation.Color to the rendered TextBlock

Project files

File / folder	Purpose
SnipIT.ps1	The whole app
Test-SnipIT.ps1	40 unit tests, no dependencies
Test-SnipIT-Interactive.ps1	42 WPF integration tests, no dependencies
docs/	Long-form docs (design mocks, deeper write-ups). docs/README.md is the index.
CHANGELOG.md	Per-merge change history (Keep a Changelog format).
SECURITY.md	Vulnerability disclosure policy + supported versions.
CLAUDE.md	Agent / contributor brief — build, test, run, conventions, OpenSSF Scorecard baseline.
shared/runbooks/engineering-standards.md	PowerShell variant of the company-canonical engineering-standards runbook.
.bestpractices.json	OpenSSF Best Practices self-assessment (project 12647).
LICENSE	MIT

Roadmap

• Scrolling / long-page capture
• Blur / pixelate annotation
• OCR via Windows.Media.Ocr — copy text from a snip
• Persisted preferences (rebindable hotkeys, default save folder, widget position)
• Capture-history gallery
• Drag-and-drop the snip out to other apps (Slack, Teams, file explorer)

License

MIT — see LICENSE.