---
title: "How to Prevent Connector Overlap in React Diagrams with Smart Line Routing"
published_at: "2026-03-10T12:31:05+00:00"
modified_at: "2026-03-12T12:48:03+00:00"
url: "https://www.syncfusion.com/blogs/post/prevent-connector-overlap-react-diagram"
excerpt: "Prevent connector overlap in React Diagram using AvoidLineOverlapping and LineRouting APIs. Create cleaner, smarter, perfectly routed diagram connectors."
taxonomy_category:
- "Data Visualization"
- "Diagram"
- "Diagram connector overlapping"
- "React"
- "React Diagram"
- "Web Development"
taxonomy_post_tag:
- "Data Visualization"
- "Diagram Connector"
- "Diagram connector overlapping"
- "Diagram connector routing"
- "React Diagram"
---
# How to Prevent Connector Overlap in React Diagrams with Smart Line Routing
[Karkuvel Rajan Shanmugavel](https://www.syncfusion.com/blogs/author/karkuvel-rajan-shanmugavel)
**TL;DR:** Messy connector lines can make diagrams difficult to read. This guide shows how to prevent overlaps using Smart Line Routing with Syncfusion React Diagram’s **`AvoidLineOverlapping`**. Learn how to keep connectors clean and readable, with a copy-ready example for flowcharts, workflows, and circuit-style diagrams.
Readable diagrams are essential when working on workflow designers, circuit editors, process maps, or architecture visualizations. Without clarity, even the best UI becomes frustrating to use. As the number of connections grows, connectors often stack on the same route, creating visual noise.
This guide shows how to prevent overlapping connector lines in React diagrams using the [AvoidLineOverlapping](https://ej2.syncfusion.com/react/documentation/diagram/connectors#avoid-line-overlapping)
API in [Syncfusion® React Diagram](https://www.syncfusion.com/react-components/react-diagram)
.
## What is line overlapping (and why it hurts UX)?
**Line overlapping** happens when multiple connectors take the same (or nearly the same) route between nodes. When lines sit directly on top of each other, users can’t tell which connector goes where.
You’ll see this often in:
- Repetitive data flows (many nodes sharing the same upstream/downstream path).
- Multi-bit circuit diagrams (parallel signals).
- Dense process maps.
- Diagrams with lots of “fan-in / fan-out” connections.
## How Syncfusion avoids connector overlap
`AvoidLineOverlapping` reduces clutter by:
- Detecting when orthogonal connector segments overlap.
- Applying small **offsets/detours** so each connector gets a distinct visible path.
It typically re-runs when:
- You add new connectors.
- You move nodes.
- Multiple connectors share the same corridor.
- Layout updates occur.
**Result:** Cleaner diagrams with less manual connector nudging.
## Prerequisites
Before you start:
- Install [Node.js](https://nodejs.org/en) and [NPM](https://www.npmjs.com/) packages.
- Install Syncfusion [React Diagram Library](https://www.npmjs.com/package/@syncfusion/ej2-react-diagrams) (@syncfusion/ej2-react-diagrams).
**Note:** New to Syncfusion React Diagram? Start with the official getting-started [guide](https://ej2.syncfusion.com/react/documentation/diagram/getting-started)
.
## Configuration checklist (required)
Before implementing the Avoid Line Overlapping feature, ensure:
1. **Enable routing in diagram constraints** You need routing enabled via constraints (**`LineRouting`**), as shown in the code snippet below:C# ``` DiagramConstraints diagramConstraints = DiagramConstraints.Default | DiagramConstraints.LineRouting ```
2. **Use orthogonal connectors**`AvoidLineOverlapping` is designed for ** orthogonal** routing. Ensure your connectors are set to use orthogonal paths.
## How to prevent connector overlap in React Diagram
Add [DiagramConstraints.AvoidLineOverlapping](https://ej2.syncfusion.com/react/documentation/api/diagram/diagramconstraints)
to your [DiagramComponent](https://ej2.syncfusion.com/react/documentation/api/diagram/index-default)
and inject the required services. This configuration ensures that your diagrams automatically manage connector paths to prevent overlapping without manual intervention.
Here’s how you can do it in code:
JavaScript
```
import * as React from "react";
import {
AvoidLineOverlapping,
ConnectorModel,
DiagramComponent,
DiagramConstraints,
Inject, LineRouting,
NodeModel,
PointPortModel,
PortVisibility,
ShapeAnnotationModel
} from "@syncfusion/ej2-react-diagrams";
```
**What this does:**
- `DiagramConstraints.LineRouting` turns on routing logic for connectors.
- `DiagramConstraints.AvoidLineOverlapping` offsets connectors when overlaps are detected.
- Inject registers the runtime services needed for routing and overlap avoidance.
## Complete example: custom nodes, ports, and orthogonal connectors
The code example below shows a practical setup where ports and orthogonal connectors are defined explicitly, common in circuit-style or workflow-style diagrams.
JavaScript
```
import * as React from "react";
import {
AvoidLineOverlapping,
type ConnectorModel
DiagramComponent,
DiagramConstraints,
Inject,
LineRouting,
type NodeModel,
type PointPortModel,
PortVisibility,
Snapping
} from "@syncfusion/ej2-react-diagrams";
function createPort(id: string, offsetX: number, offsetY: number): PointPortModel {
return {
id,
offset: { x: offsetX, y: offsetY },
visibility: PortVisibility.Visible
};
}
export default function AvoidOverlapDiagram() {
const nodes: NodeModel[] = [
{
id: "A",
offsetX: 150,
offsetY: 150,
width: 120,
height: 60,
annotations: [{ content: "Node A" }],
ports: [
createPort("A_out1", 1, 0.35),
createPort("A_out2", 1, 0.65)
]
},
{
id: "B",
offsetX: 350,
offsetY: 200,
width: 120,
height: 60,
annotations: [{ content: "Node B" }],
ports: [
createPort("B_in1", 0, 0.35),
createPort("B_in2", 0, 0.65)
]
}
];
const connectors: ConnectorModel[] = [
{
id: "c1",
sourceID: "A",
sourcePortID: "A_out1",
targetID: "B",
targetPortID: "B_in1",
type:"Orthogonal",
},
{
id: "c2",
sourceID: "A",
sourcePortID: "A_out2",
targetID: "B",
targetPortID: "B_in2",
type:"Orthogonal"
}
];
return (
);
}
```
**What to notice:**
- Both connectors would naturally try to share a similar route between Node A and Node B.
- With `AvoidLineOverlapping`, the component offsets them so both paths remain visible.
## Why this feature matters (practical wins)
- **Better readability:** Users can trace each connection without guessing.
- **Less manual cleanup:** Connectors adjust when nodes move, or new links appear.
- **Scales to dense diagrams:** Helpful for fan-in/fan-out patterns and multi-connector corridors.
Preventing connector overlap in React Diagram
## GitHub reference
For a complete working sample, refer to the [GitHub](https://github.com/syncfusion/ej2-react-samples/blob/master/src/diagram/avoid-connector-overlap-functional.tsx)
demo to avoid line overlapping.
## Frequently Asked Questions
Does AvoidLineOverlapping work with all connector types?No. `AvoidLineOverlapping` is designed specifically for **Orthogonal** connectors. If your connectors use ** Straight** or ** Bezier** routing, the overlap‑avoidance logic will not apply.
Will enabling AvoidLineOverlapping affect diagram performance?In large diagrams with many connectors, enabling `AvoidLineOverlapping` may introduce **slight routing overhead** because the algorithm recalculates and offsets connectors dynamically. However, in typical workflow and process diagram scenarios, the performance impact is minimal and optimized to run efficiently with LineRouting.
Do connectors automatically re-adjust when nodes move?Yes. When a node is moved, resized, or new connectors are added, the **`AvoidLineOverlapping` logic re-runs**. This ensures connectors continuously avoid overlapping without requiring manual adjustments from the user.
## Conclusion
Thank you for reading! To prevent connector [overlapping](https://ej2.syncfusion.com/react/documentation/diagram/connectors#avoid-line-overlapping)
in [React Diagram](https://www.syncfusion.com/react-components/react-diagram)
, enable **LineRouting**, use ** orthogonal connectors**, and turn on ** AvoidLineOverlapping**. You’ll get cleaner visuals with far less manual connector work, especially as your diagrams scale in complexity.
For deeper configuration options, see the official **Syncfusion React Diagram**[documentation](https://ej2.syncfusion.com/react/documentation/diagram/getting-started)
.
If you’re a Syncfusion user, you can download the setup from the [license and downloads](https://www.syncfusion.com/sales/pricing)
page. Otherwise, you can download a free [30-day trial](https://www.syncfusion.com/downloads/)
.
You can also contact us through our [support forum](https://www.syncfusion.com/forums)
, [support portal](https://support.syncfusion.com/)
, or [feedback portal](https://www.syncfusion.com/feedback)
for queries. We are always happy to assist you!
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