Documentation

Everything you need to know to master HoverScribble

Introduction

HoverScribble is a professional screen annotation tool for Windows that creates a transparent overlay for drawing, highlighting, and presenting on top of any application. Whether you're a teacher, presenter, content creator, or just need to annotate your screen, HoverScribble provides all the tools you need.

System Requirements: Windows 10 or later, .NET 8 Runtime (included in installer)

Key Features

  • Draw on top of any application with pen, highlighter, and shape tools
  • Pressure-sensitive stylus support for natural drawing
  • Laser pointer and spotlight for presentations
  • Whiteboard and blackboard modes
  • Screenshot capture with annotations
  • Built-in calculator with 4 modes
  • Customizable keyboard shortcuts

Quick Start

Get started with HoverScribble in just a few steps:

1. Launch HoverScribble

After installation, launch HoverScribble from the Start menu or desktop shortcut. The floating toolbar will appear on your screen.

2. Select a Tool

Click on any tool in the toolbar to select it. The pen tool is selected by default.

3. Start Drawing

Click and drag anywhere on the screen to draw. Your strokes will appear on top of all other windows.

4. Switch to Mouse Mode

When you need to interact with your applications normally, click the mouse icon or press Ctrl+Shift+M to enable click-through mode.

Pro Tip: Press Ctrl+Shift+P at any time to toggle HoverScribble on/off. This is the global hotkey that works even when HoverScribble is minimized.

Essential Shortcuts & Tips

ESC Key Behavior:

  • If whiteboard/blackboard is active → Turns it off
  • If using any drawing tool → Switches to Mouse mode
  • If toolbar is visible → Enter mini mode (small floating icon)
  • If in mini mode → Hides to system tray
Adjust stroke size Mouse Scroll
Quick color 1-8 1-8 keys
Undo last stroke Ctrl+Z
Exit/Back ESC

Colors & Color Picker

HoverScribble provides multiple ways to select and customize colors for your annotations.

Quick Color Selection

The toolbar displays 8 quick-access color buttons. Click any color to select it immediately, or press number keys 1-8 to select colors by position.

Default Colors Position
■ Black1
■ White2
■ Red3
■ Orange4
■ Yellow5
■ Green6
■ Blue7
■ Purple8

Advanced Color Picker

Click the color picker button (palette icon) to open the full color picker with:

  • Color Spectrum: Click anywhere on the gradient to select a color
  • Hue Slider: Drag to change the base hue
  • RGB Sliders: Fine-tune Red, Green, Blue values (0-255)
  • Hex Input: Enter exact hex color codes (e.g., #FF5733)
  • Recent Colors: Quick access to recently used colors

Eyedropper Tool

Pick any color from anywhere on your screen:

  1. Open the Color Picker
  2. Click the eyedropper icon
  3. Move your cursor over any pixel on screen
  4. Click to capture that color
  5. Press ESC to cancel

Tip: Customize the 8 default toolbar colors in Settings → Default Colors. Your choices are saved and persist between sessions.

Drawing Tools

HoverScribble provides a variety of drawing tools for different annotation needs.

Pen

Standard drawing tool

The primary drawing tool with smooth, pressure-sensitive strokes. Perfect for writing and freehand drawing.

Ctrl+Shift+D

Highlighter

Semi-transparent marker

Semi-transparent strokes for highlighting text and important areas without obscuring content.

Ctrl+Shift+H

Calligraphy

Angled brush tip

Creates beautiful calligraphic strokes with an angled tip that varies in thickness based on direction.

Settings → Enable

Crayon

Textured crayon effect

Simulates a crayon with textured, slightly uneven strokes for a hand-drawn artistic feel.

Settings → Enable

Spray Paint

Spray can effect

Creates a spray paint effect with scattered dots, perfect for graffiti-style annotations.

Settings → Enable

Eraser

Remove strokes

Removes strokes by touching them. Works on any stroke type including shapes and text.

Ctrl+Shift+E

Pen Tool

The Pen is HoverScribble's primary drawing tool, designed for smooth, natural strokes.

Features

  • Pressure Sensitivity: When using a stylus, stroke thickness varies with pressure
  • Smooth Drawing: Quadratic Bezier curves smooth out jagged strokes
  • Color Selection: Choose from preset colors or use the custom color picker
  • Adjustable Thickness: Use the slider to change stroke width

Settings

Setting Description Default
Pressure Sensitivity Enable/disable pressure-based thickness Enabled
Sensitivity Strength How much pressure affects thickness (0-200%) 100%
Smooth Drawing Apply smoothing to strokes Enabled
Smooth Handwriting Extra smoothing for mouse users Disabled

Highlighter

The highlighter creates semi-transparent strokes that allow underlying content to remain visible. It's perfect for marking up documents, emphasizing text, or drawing attention to specific areas.

  • 35% opacity by default, adjustable per tool in Settings › Tools
  • Uses the Darken blend, so crossing your own highlight stays one flat wash instead of building up toward black
  • Keeps its own size and colour, separate from the pen
  • Works great with bright colors like yellow and green

On the Darken blend a highlight is drawn as one even band, so stylus pressure does not vary its width. Switch that tool to the Normal blend in Settings › Tools if you want pressure to come through.

Shape Tools

Create perfect geometric shapes by clicking and dragging. Hold Shift while drawing for proportional shapes (perfect circles and squares).

Rectangle

Draw rectangles and squares. Hold Shift for perfect squares.

Ctrl+Shift+R

Ellipse

Draw ellipses and circles. Hold Shift for perfect circles.

Ctrl+Shift+O

Triangle

Draw triangles pointing in the direction you drag.

Settings → Enable

Lines & Arrows

Use lines and arrows to point out important elements or show connections between items.

Line

Draw straight lines between two points.

Ctrl+Shift+L

Arrow

Draw arrows that point from start to end position.

Ctrl+Shift+A

Advanced Shapes

HoverScribble includes a variety of advanced shapes for more complex annotations. Enable them in Settings → Enabled Tools.

Shape Description
Diamond Rotated square shape
Star 5-pointed star
Pentagon 5-sided polygon
Hexagon 6-sided polygon
Heart Heart shape
Cloud Cloud/thought bubble
Lightning Lightning bolt
Checkmark Checkmark/tick symbol
X Mark X/cross symbol
Plus Plus sign
Minus Minus sign
Block Arrow Thick block arrow
Speech Bubble Comic-style speech bubble

Text Tool

Add text annotations anywhere on the screen. Click to place text, then type your message.

  • Click anywhere to place text
  • Customizable font family and size
  • Drag to reposition after placing
  • Double-click to edit existing text
Setting Description Default
Font Family The font used for text Segoe UI
Font Size Size of the text in points 24

Laser Pointer

A bright, attention-grabbing pointer that follows your cursor. Perfect for presentations when you need to point out specific items without leaving permanent marks.

  • Bright red glowing dot visible on any background
  • Click-through enabled - interact with apps while using
  • Adjustable size in settings
Setting Description Default
Laser Size Diameter of the laser pointer in pixels 24

Spotlight

Dims the entire screen except for a circular area around your cursor. Use this to focus your audience's attention on a specific area.

  • Darkens screen to 70% opacity outside spotlight
  • Adjustable spotlight radius
  • Click-through enabled for interaction
Setting Description Default
Spotlight Size Radius of the spotlight in pixels 100

Ruler

Place on-screen rulers to draw straight lines, measure distances, or align elements. You can have up to 6 rulers on screen at once.

  • Click to place rulers anywhere on screen
  • Drag to move, drag ends to resize
  • Rotate handles for angle adjustment
  • Snap to angles (configurable)
  • Draw along ruler edge for straight lines
  • Double-click to remove a ruler
Setting Description Default
Snap Angle Angle increment for snapping (0 = off) 15°
Default Length Initial ruler length in pixels 400

Fading Ink

When enabled, your strokes will gradually fade away after a set duration. This is perfect for presentations where you want to draw attention to something temporarily.

Toggle fading ink on/off with Ctrl+Shift+F or click the fading ink button in the toolbar.

Setting Description Default
Fading Duration How long strokes take to fade (milliseconds) 4000 (4 seconds)

Whiteboard & Blackboard

Create a colored background for drawing. Toggle between white and black colors, and choose how much of your screen to cover.

Color Options

  • Whiteboard (Ctrl+Shift+W): White background, great for teaching
  • Blackboard (Ctrl+Shift+B): Dark background, easier on eyes
  • Your color preference is remembered between sessions

Coverage Options

Click the dropdown arrow next to the board button to access coverage options:

Option Description
Single Screen Board covers only the monitor where the toolbar is located
All Screens Board covers all monitors (default)
Choose Area Drag to select a custom rectangular area to cover

Usage

  • Click the board button to toggle on/off using your last selected color
  • Click the dropdown arrow to switch colors or change coverage area
  • The button icon shows your current color selection (white or black)

Screenshot

Capture screenshots with your annotations included. Press Ctrl+Shift+S for your default mode, or click the small arrow beside the screenshot button to pick a different one for this capture.

Mode Description
Current Screen Captures the monitor where the toolbar is located
All Screens Captures all monitors as one image
Rectangle Area Drag a rectangle. The screen freezes while you aim.
Ellipse Area Drag an ellipse. Saved as a PNG with transparent corners.
Freehand Area Trace any shape. Saved masked to that outline.
Rectangle → Pin 1.4 Capture a region and float it on top of everything, just this once

Since 1.4 you control where captures go. See Capture Output for the clipboard/file destination, save folder and filename pattern, Freeze & Magnifier for the selection overlay, and Pinned Captures for floating a capture on screen.

Calculator

A built-in calculator with four modes: Basic, Scientific, Graphing, and Matrix. Access it quickly without leaving HoverScribble.

Basic Calculator

Standard calculator for everyday arithmetic:

  • Operations: +, -, ×, ÷, %
  • Memory Functions: MC (clear), MR (recall), M+ (add to memory), M- (subtract from memory)
  • Clear: C (clear entry), AC (all clear)
  • Keyboard: Type numbers and operators directly

Scientific Calculator

Advanced functions for scientific and engineering calculations:

Category Functions
Trigonometry sin, cos, tan, asin, acos, atan, sinh, cosh, tanh
Logarithms log (base 10), ln (natural log), log₂
Powers & Roots x², x³, xⁿ, √, ³√, ⁿ√, 10ˣ, eˣ
Other |x| (absolute), n! (factorial), 1/x (reciprocal), +/- (negate)
Constants π (pi = 3.14159...), e (Euler = 2.71828...)

RAD/DEG Toggle: Switch between radians and degrees for trigonometric functions. Default is Degrees.

Graphing Calculator

Visualize mathematical functions with an interactive graph:

  • Plot Functions: Enter equations like sin(x), x^2, 2*x+1
  • Multiple Graphs: Add multiple functions with different colors
  • Zoom: Scroll to zoom in/out on the graph
  • Pan: Click and drag to move around the coordinate system
  • Derivative (f'): Toggle to show the derivative of your function
  • Integral (∫f): Toggle to show the integral/antiderivative
  • Color Picker: Customize each function's graph color
  • Trace: Hover over graph to see (x, y) coordinates

Supported Syntax: Use x as the variable. Supported: +, -, *, /, ^ (power), sqrt(), sin(), cos(), tan(), log(), ln(), abs(), pi, e

Matrix Calculator

Perform operations on matrices up to 4×4:

Operation Description
Determinant (det) Calculate the determinant of a square matrix
Inverse (A⁻¹) Find the inverse matrix (if determinant ≠ 0)
Transpose (Aᵀ) Swap rows and columns of the matrix
Size Selection Choose matrix dimensions: 2×2, 3×3, or 4×4

Calculator Settings

Setting Description Default
Default Mode Which calculator mode opens by default Scientific

Story Mode

Automatically capture screenshots at regular intervals to create a visual timeline of your work. Great for creating tutorials or documenting processes.

  • Automatic periodic screenshots
  • Smart duplicate detection - skips similar frames
  • Optional PDF generation at end
Setting Description Default
Capture Interval Seconds between captures 10
Max Duration Maximum recording time in minutes 60
Similarity Threshold How similar frames need to be to skip (0.98-1.0) 0.998
Generate PDF Create PDF at end of recording Yes

Per-Tool Settings New in 1.4

Every tool now remembers its own size, colour, opacity and blend mode. Set your pen to a thin black line and your highlighter to a fat amber wash, and each one comes back exactly as you left it. Before 1.4 there was a single shared size and colour, so switching tools meant re-adjusting every time.

Pen 4 px 100% Normal size · colour · opacity · blend Highlighter 18 px 35% Darken kept separately from the pen switch Darken blend crossing stays the same shade Normal blend crossing builds up darker
Each tool keeps its own four settings. The highlighter ships with the darken blend so overlapping strokes stay one flat wash instead of stacking toward black.

Setting it up

  1. Pick a tool on the toolbar, then set its size with the thickness slider (or the mouse wheel over the screen) and its colour from the swatches. That writes to that tool only.
  2. Open Settings → Tools for the two settings that are not on the toolbar: Opacity and Blend.
  3. Choose the tool you want to edit from the Tool dropdown. The size, colour, opacity and blend shown below it belong to that tool.
  4. Press Save. Everything persists across restarts.
SettingWhat it doesDefault
SizeStroke width for that toolPen 4px, highlighter 18px
ColourFollows the toolbar swatch while the tool is activePen black, highlighter amber
OpacityBase alpha of the strokePen 100%, highlighter 35%
BlendNormal, or Darken to stop overlaps building upHighlighter uses Darken
Link size across all toolsRestores the pre-1.4 behaviour of one shared sizeOff

Tip: Upgrading from an earlier version? Your old shared thickness and colour are copied into every tool, so nothing looks different on the first launch. Only the highlighter moves to its new 35% darken default. Use Reset this tool to defaults on the Tools tab if you want the shipped values back.

Pass-Through Mode New in 1.4

Pass-through lets you work in the app underneath without losing your annotations. The overlay stays on screen and your ink stays exactly where it is, but every click, scroll and keystroke goes straight through to whatever is below.

DRAW Play ink PASS-THROUGH Play click goes through green edge = pass-through is on the overlay takes the click
Your ink is identical in both panels. Only where the click lands changes.

Two ways to switch

MethodHowBest for
Tap to toggleCtrl+Shift+MWorking underneath for a while. Press it again to return to the exact tool you were using.
Hold for a momentHold Ctrl+AltOne quick click below, such as pausing a video, then straight back to drawing the instant you let go.

Recording a tutorial? The hold is the one to learn. Annotate, hold Ctrl+Alt, hit pause in your video player, release, and carry on drawing. No tool switching, no lost ink.

Settings

SettingWhat it doesDefault
Show screen-edge tintGreen border around each monitor while passing through, so you never draw into a dead overlay by mistakeOn
Tint colourGreen, amber, indigo or redGreen
Hold for momentary pass-throughWhich keys to hold, or OffCtrl+Alt
Clear ink when switching modesWipes annotations on every switchOff

The tint appears only when you switch on purpose with the hotkey or the hold. Simply selecting the mouse tool will not paint a border around your screen. Note that exclusive-fullscreen games and DRM-protected video may not composite the overlay at all, in either mode.

Capture Output New in 1.4

Captures no longer always land as a file in one fixed folder. You choose where they go, what they are called, and you can send one straight to the clipboard without touching your settings.

Capture Ctrl+Shift+S Send captures to Clipboard + file Clipboard paste straight into chat or a doc File your folder, your filename pattern Shot_001_1920x1080.png
Destination, folder and filename all live on the Capture tab in Settings.

Filename tokens

The filename box accepts tokens in braces. A live example updates underneath as you type.

TokenBecomes
{date} {time}20260904 · 143005
{datetime}20260904_143005
{counter}001, 002, 003 within the session
{width} {height}Pixel size of the capture
Any date format{yyyy-MM-dd} becomes 2026-09-04

Clipboard in one key: Ctrl+Shift+G selects a region and copies it, without writing a file, whatever your destination setting says. Handy when you just want to paste something and not leave a PNG behind.

Freeze & Magnifier New in 1.4

When you start a region capture, the screen freezes. Nothing moves while you aim, so you can capture a tooltip, a dropdown, or a video frame without it disappearing. A magnifier at the cursor lets you land the edge on the exact pixel.

240 x 130 824, 517 crosshair + live coordinates magnifier loupe everything else dimmed
The selection stays bright, everything around it dims, and the loupe shows the exact pixel under the crosshair.

While the overlay is open

Key or actionResult
DragSelect the region. The readout shows width by height as you go.
Release or EnterConfirm the capture
Esc or right-clickCancel. Nothing is written.
MToggle the magnifier

Freeze works for all three region shapes: rectangle, ellipse and freehand. Ellipse and freehand captures are saved as PNGs with transparency outside the shape.

Need the live picture instead, for example to catch something mid-animation? Turn off Freeze the screen while selecting on the Capture tab. Everything else about the overlay stays the same.

Pinned Captures New in 1.4

A pin is a borderless, always-on-top copy of a capture that floats above every other window. Keep a reference screenshot in the corner while you work, compare two versions side by side, or park a diagram where you can see it.

drag anywhere to move wheel to zoom corners resize right-click for the menu copy · save · size · opacity · click-through · close
Pins are excluded from your own captures, so a screenshot never photographs a previous one.

Making a pin

WayWhen to use it
Ctrl+Shift+JSelect a region and pin it, right now
Screenshot arrow → Rectangle → PinSame thing without the keyboard
Settings → Capture → Pin automatically after every captureYou want every capture pinned Off by default

Handling a pin

ActionResult
Drag the middleMove it
Mouse wheelZoom around the cursor, aspect ratio locked
Drag a cornerResize, aspect ratio locked
Right-clickCopy, Save as, Size (25 to 200%), Opacity, Click through, Close, Close all
Ctrl+Shift+YClose every pin at once

Click-through pins

A pin can be made to ignore the mouse entirely, so you can see it but click straight through to whatever is underneath. Useful for keeping a reference visible over a window you are actively using.

ActionResult
Ctrl+Shift+K with the cursor over a pinToggle click-through for that pin
Ctrl+Shift+K away from any pinToggle every pin at once

A click-through pin cannot be right-clicked, because the mouse goes past it. It shows a dashed amber frame to remind you, and the way back is Ctrl+Shift+K while hovering it, or Ctrl+Shift+Y to close all pins.

Turn on Restore pins on restart to have your pins reappear in the same place after you close and reopen HoverScribble. Off by default.

Settings

Open Settings from the gear icon on the toolbar, or from the tray icon. The window has four tabs: Settings for everything below, Tools for per-tool drawing settings and pass-through, Capture for screenshots and pins, and Instructions. Changes apply when you press Save.

Access settings by clicking the gear icon in the toolbar. Settings are saved automatically to %APPDATA%/HoverScribble/settings.json.

General Settings

Setting Description Default
Start with Windows Launch HoverScribble when Windows starts. Adds entry to Windows startup registry. Off
Start Minimized Start hidden in system tray instead of showing toolbar Off
Minimize to Tray When minimized, hide to system tray instead of taskbar On
Show Status Indicator Display current tool name in corner of screen On

Toolbar Settings

Setting Range Effect Default
Toolbar Opacity 0% - 100% Lower = more transparent toolbar. 0% makes toolbar invisible (not recommended) 95%
Compact Mode On/Off On = smaller buttons, fits more tools. Off = larger buttons, easier to click On
Vertical Toolbar On/Off On = toolbar arranged in column. Off = toolbar arranged in row Off
Dual Row Mode On/Off On = tools in 2 rows/columns (compact). Off = single row/column (longer) On
Icon Scale 75% - 150% Scales entire toolbar. 75% = small for large monitors. 150% = large for touch/accessibility 100%

Drawing Settings

Setting Range Effect Default
Default Color Any color Starting colour. Since 1.4 each tool also stores its own colour, which takes over once you pick that tool. See Per-Tool Settings. Black (#000000)
Default Thickness 1 - 50 px Starting stroke width. Since 1.4 each tool stores its own size, which takes over once you pick that tool, unless Link size across all tools is on. 4
Default Tool Any tool Tool selected when HoverScribble starts Pen
Pressure Sensitivity On/Off On = stylus pressure affects stroke width. Off = constant width On
Pressure Strength 0% - 200% How much pressure affects thickness. 0% = no effect, 200% = very dramatic 100%
Smooth Drawing Apply curve smoothing On
Enable Hotkeys Allow global keyboard shortcuts On

Tools Tab New in 1.4

Per-tool drawing settings and pass-through behaviour. Pick a tool from the Tool dropdown first: the size, opacity, blend and colour shown below it belong to that tool alone. Full detail in Per-Tool Settings and Pass-Through Mode.

Setting Options Description Default
Tool Any drawing tool Chooses which tool the settings below apply to Pen
Size 1 - 60 px Stroke width for the selected tool only Pen 4, highlighter 18
Opacity 5% - 100% Base transparency of the stroke, before any fading Pen 100%, highlighter 35%
Blend Normal, Darken Darken stops overlapping strokes of one colour from building up toward black. This is what keeps a highlighter readable where it crosses itself. Darken on the highlighter
Link size across all tools On/Off On restores the pre-1.4 behaviour where one size is shared by every tool Off
Reset this tool to defaults Button Puts the selected tool back to its shipped size, colour, opacity and blend –
Show screen-edge tint On/Off Coloured border around each monitor while pass-through is on, so you never draw into an overlay that is not listening On
Tint colour Green, amber, indigo, red Colour of that border Green
Clear ink when switching modes On/Off Wipes your annotations every time you switch into or out of pass-through Off
Hold for momentary pass-through Off, Ctrl+Alt, Ctrl+Shift, Alt+Shift, Right Alt, Right Ctrl Keys you hold to pass input through for a moment, releasing to return straight to drawing Ctrl+Alt

Capture Tab New in 1.4

Where captures go, how the selection overlay behaves, and how pins work. Full detail in Capture Output, Freeze & Magnifier and Pinned Captures.

Setting Options Description Default
Send captures to Clipboard and file, Clipboard only, File only Where every capture is delivered Clipboard and file
Save folder Any folder Leave blank for Pictures\HoverScribble Blank
Filename Text with tokens Pattern for saved files. Supports {date} {time} {datetime} {counter} {width} {height} and any date format such as {yyyy-MM-dd}. A live example updates as you type. Screenshot_{date}_{time}
Freeze the screen while selecting On/Off Holds the picture still while you aim, so menus and tooltips cannot vanish mid-capture. Turn off to capture something that is still moving. On
Show magnifier loupe On/Off Pixel-level zoom at the cursor during a region capture. Press M while selecting to toggle it. On
Pin automatically after every capture On/Off Every capture also becomes a floating pin. For a one-off pin, use Ctrl+Shift+J instead. Off
Restore pins on restart On/Off Brings your pins back in the same place next time you open HoverScribble Off
Default pin opacity 20% - 100% Transparency a new pin starts at. Each pin can be changed afterwards from its right-click menu. 100%
Include HoverScribble UI in captures On/Off Off keeps pins and the selection overlay out of your captures, so a screenshot never photographs a previous one. Your ink is always captured either way. Needs Windows 10 version 2004 or later. Off

Keyboard Shortcuts

HoverScribble supports customizable keyboard shortcuts. All shortcuts use Ctrl+Shift as a modifier to avoid conflicts with other applications.

Toggle HoverScribble Ctrl+Shift+P
Pass-through (toggle) Ctrl+Shift+M
Pass-through (hold) Ctrl+Alt
Capture to clipboard Ctrl+Shift+G
Capture and pin Ctrl+Shift+J
Pin click-through Ctrl+Shift+K
Close all pins Ctrl+Shift+Y
Pen Tool Ctrl+Shift+D
Highlighter Ctrl+Shift+H
Eraser Ctrl+Shift+E
Line Ctrl+Shift+L
Arrow Ctrl+Shift+A
Rectangle Ctrl+Shift+R
Ellipse Ctrl+Shift+O
Text Ctrl+Shift+T
Ruler Ctrl+Shift+U
Whiteboard Ctrl+Shift+W
Blackboard Ctrl+Shift+B
Fading Ink Ctrl+Shift+F
Clear Canvas Ctrl+Shift+C
Screenshot Ctrl+Shift+S
Undo Ctrl+Z
Mini Mode Ctrl+Shift+N
Minimize Ctrl+Shift+X

Shortcuts can be customized in Settings. All shortcuts are saved to your settings file.

Toolbar Customization

The toolbar can be fully customized to show only the tools you need.

Enabling/Disabling Tools

Open Settings and go to "Enabled Tools" to toggle individual tools on or off. Disabled tools will not appear in the toolbar.

Custom Colors

The toolbar shows 8 quick-access colors. You can customize these in Settings under "Default Colors". Click on any color swatch to change it.

Toolbar Position

Drag the toolbar by its edge to reposition it anywhere on screen. The position is saved between sessions.

Mini Mode: Press Ctrl+Shift+N to toggle a minimal toolbar with just essential tools.