Diagrammix3 offers 30+ arrowhead types for connectors, covering standard arrows, UML notation, ERD (Entity-Relationship Diagram) symbols, and technical diagram markers.
How to Use This Reference
Each arrowhead type is shown with:
- Visual preview - What it looks like
- Name - How it appears in the Inspector
- Common use - When to use it
- Category - Type classification
To apply an arrowhead:
- Select a connector
- Open the Inspector panel
- Find the Connector section
- Choose Start Arrowhead or End Arrowhead
- Select from the gallery

Standard Arrows
None
Preview: ────────Use: No arrow needed, simple lines, undirected relationships
Standard Arrow
Preview: ────────>Use: General purpose, default arrowhead, shows direction
Inflected Arrow
Preview: ────────⟩Use: Softer alternative to standard arrow, presentations
Circle Markers
Circle (Filled)
Preview: ────────●Use: UML composition (when on source), end markers, highlights
Circle (Stroked/Hollow)
Preview: ────────○Use: UML aggregation, weak relationships, alternate end markers
Square Markers
Square (Filled)
Preview: ────────■Use: Data flow endpoints, process terminators, strong markers
Square (Stroked/Hollow)
Preview: ────────□Use: Optional endpoints, weak markers, alternate notation
Diamond Markers
Diamond (Filled)
Preview: ────────◆Use: UML composition, strong ownership, part-whole relationships
Diamond (Hollow/Stroked)
Preview: ────────◇Use: UML aggregation, weak ownership, collection relationships
Diamond (Curved)
Preview: ────────◊Use: Stylized alternative to standard diamonds
Triangle Markers
Triangle (Standard Filled)
Preview: ────────▶Use: Standard arrow, directional flow, general purpose
Triangle (Hollow/White)
Preview: ────────▷Use: UML inheritance/generalization, IS-A relationships, class hierarchy
Feather Markers
Single Feather
Preview: ────────⟨Use: Alternate directional marker, lighter visual weight
Double Feather
Preview: ────────⟪Use: Strong directional emphasis, nested relationships
Triple Feather
Preview: ────────⟪⟨Use: Very strong directional emphasis, multiple-level relationships
Dimension & Technical
Dimension Line
Preview: ────────┤Use: Technical drawings, measurements, architectural diagrams
Dimension Bar
Preview: ────────┃Use: Start/end markers for dimension lines, tick marks
Bar
Preview: ────────┃Use: Terminators, endpoints, barriers
Stick/Chevron
Preview: ────────⟩Use: Lightweight directional indicator
UML-Specific
UML Inheritance (Triangle Hollow)
Preview: ────────△Use: Inheritance arrow in UML class diagrams (extends, implements)
UML Cross (X)
Preview: ────────✕Use: Destroy message in UML sequence diagrams, termination
ERD (Entity-Relationship) Notation
Crow's Foot
Preview: ────────⋚Use: "Many" side of relationship, one-to-many or many-to-many
Crow's Foot + Bar
Preview: ────────┃⋚Use: Mandatory many (at least one required)
Crow's Foot + Circle
Preview: ────────○⋚Use: Optional many (zero or more allowed)
Bar + Bar
Preview: ────────┃┃Use: Exactly one (mandatory one), one-to-one
Circle + Bar
Preview: ────────○┃Use: Zero or one (optional one)
Circle + Circle
Preview: ────────○○Use: Zero (rare, used for optional endpoints)
Bar + Circle
Preview: ────────┃○Use: One or zero (alternate notation)

Box Markers
Box (Filled)
Preview: ────────▪Use: Heavy markers, emphasis, terminators
Box (Stroked/Hollow)
Preview: ────────▫Use: Light markers, alternate endpoints
Arc/Curve Markers
Arc (Crescent Stroked)
Preview: ────────⌒Use: Stylized arrows, decorative connectors, smooth transitions
Combining Arrowheads
Connectors can have different arrowheads at each end:
Example combinations:
- None → Standard Arrow: Simple directional flow
- Circle → Standard Arrow: Source marker with direction
- Diamond (Filled) → Triangle (Hollow): UML composition to inheritance
- Bar → Crow's Foot: ERD relationship (one-to-many)
- Dimension Bar → Dimension Bar: Measurement line with tick marks

Arrowhead Sizing
Adjust arrowhead size in the Inspector:
- Small - Subtle, detailed diagrams
- Medium - Default, balanced appearance
- Large - Emphasis, presentations, large diagrams
Arrowhead size scales proportionally with connector stroke width.
Arrowhead Colors
Arrowheads can use:
- Same as line color - Unified appearance (default)
- Independent color - Color-coded arrowheads for categorization
- Color scheme linked - Theme-aware arrowhead colors

Notation Quick Reference
For UML Class Diagrams
- Inheritance: Triangle (Hollow) pointing to parent class
- Composition: Diamond (Filled) on the container side
- Aggregation: Diamond (Hollow) on the container side
- Dependency: Dashed line with Standard Arrow
- Association: Standard Arrow or None
For UML Sequence Diagrams
- Synchronous Message: Standard Arrow (solid line)
- Asynchronous Message: Standard Arrow (solid line, half-arrow variant)
- Return Message: Dashed line with Standard Arrow
- Destroy Message: UML Cross (X)
For ERD Diagrams
- One: Bar (┃)
- Many: Crow's Foot (⋚)
- Mandatory: Bar
- Optional: Circle (○)
- Combine for cardinality: "Zero or Many" = Circle + Crow's Foot
For Flowcharts
- Standard Flow: Standard Arrow
- No Arrow: Between sequential process boxes
- Data Flow: Standard Arrow with label
For Network Diagrams
- Directional: Standard Arrow shows data flow direction
- Bidirectional: Arrows on both ends
- No Arrow: Physical connections without implied direction
Tips
- Be consistent - Use the same arrowhead type for the same relationship type
- Match conventions - UML and ERD have standard arrowhead meanings
- Don't overuse variety - Stick to 2-3 arrowhead types per diagram
- Size appropriately - Larger arrowheads for presentations, smaller for detailed work
- Color for emphasis - Use colored arrowheads sparingly for key relationships
Related Topics
- Connectors - Basic connector usage
- UML Class Diagrams - UML-specific notation
- Smart Connectors - Routing modes
- Stroke Styles - Connector line appearance