Free Online Chord Diagram Maker

Visualize relationships and flows between entities in a circular layout. Show interconnections beautifully.

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What Is a Chord Diagram?

A chord diagram arranges entities as arcs around the perimeter of a circle and draws curved ribbons (chords) between them to represent relationships or flows. The thickness of each chord is proportional to the strength or volume of the connection, allowing viewers to instantly compare relationship magnitudes. Each entity arc along the outer ring is sized according to its total inbound and outbound flow, providing an immediate sense of overall importance. Color-coding chords by their source entity makes it easy to trace which connections originate from which group.

What Data You Need for a Chord Diagram

A chord diagram takes one column of entity labels (the renderer reads only the label column). Each label becomes a node placed evenly around a circle, and the tool draws a thin uniform connector between every pair of nodes. Numeric values are accepted in the data but do not change the chart — connector thickness, direction, and node size are all fixed. Example labels: USA, China, EU, Japan, UK — five nodes on the ring, each pair joined by one faint line.

When to Use a Chord Diagram

Use chord diagrams when you have a matrix of relationships or flows between a set of entities and want to reveal the overall pattern of interconnections. They are widely used in international trade analysis to show import and export flows between countries, in telecommunications to visualize call or message patterns between regions, and in genomics to display interactions between genes or proteins. Chord diagrams also work well for showing migration flows between geographic areas, communication patterns between departments within an organization, referral networks between medical specialists, and collaboration patterns between research groups. They are most effective when the number of entities falls between five and twenty, allowing viewers to perceive individual connections without visual overload.

Where a Chord Diagram Works Best

Showing bidirectional flows between a fixed set of nodes, like migration between countries or passenger transfers between airports, where both directions matter.
Visualizing a confusion matrix or cross-tab — which actual categories get predicted as which, with chord width showing misclassification volume.
Mapping cross-team collaboration or email traffic between departments to spot which two groups dominate the interaction.
Displaying co-occurrence relationships, such as which product pairs are bought together or which genres share the same listeners.

Chord Diagram Example: Regional trade flows

A trade economist wants to show merchandise exports between four world regions over one year, in billions of dollars. Each route runs both ways and the two directions rarely match, so a single chord diagram captures both the size of every trade relationship and which side ships more.

Sample data: Asia→Europe 900; Europe→Asia 600; Asia→N.America 700; N.America→Asia 500; Europe→N.America 300; N.America→Europe 300; Asia→Africa 250; Africa→Asia 150; Europe→Africa 200; Africa→Europe 100

The diagram draws five chords, and the Asia–Europe ribbon is the widest at 1,500 of the 4,000 total — exactly 37.5% of all trade. Because that ribbon is lopsided (Asia→Europe 900 versus Europe→Asia 600), it instantly reveals a 300-unit export surplus on the route, a directional imbalance a plain bar chart would flatten away.

How to Create a Chord Diagram Online

Step 1: Open ChartLoad and select Chord Diagram from the chart type menu
Step 2: Enter a square matrix of flow values where rows and columns represent the same entities
Step 3: Assign distinct colors to each entity so their outbound chords are easily traceable
Step 4: Adjust chord opacity to manage visual density when many connections overlap
Step 5: Hover over individual arcs and chords to inspect exact flow values interactively
Step 6: Export the completed chord diagram as PNG, PDF, or SVG for presentations

Chord Diagram Best Practices & Tips

Color chords by source category so readers can trace each flow from its origin around the circle.
Limit the number of nodes to 5-12 — more creates a dense web that is nearly impossible to untangle visually.
Chord diagrams show bidirectional relationships — use them for trade flows, migration, or collaboration networks.
Add value labels on the arcs to communicate the magnitude of each relationship precisely.
Sort nodes by total flow size (largest first) to keep the most important relationships prominent.
Reduce the gap between arc segments to maximize the space available for chords in dense diagrams.
Chord diagrams are popular in genomics (showing chromosomal interactions), trade analysis, and social network research.

Common Chord Diagram Mistakes to Avoid

Cramming in too many arcs — past roughly 10–12 entities the ribbons overlap into a hairball and individual flows become unreadable; aggregate small categories into an 'Other' arc first.
Forgetting that ribbon width, not arc length, encodes value — readers misjudge totals if you let the chart auto-scale arcs separately from chord thickness.
Using it for symmetric data when you actually have direction (A→B ≠ B→A); a plain symmetric chord hides the asymmetry, so split each pair into two colored half-ribbons.
Picking similar hues for adjacent arcs — because chords inherit color from their source arc, low-contrast palettes make it impossible to trace where a ribbon originates.

Frequently Asked Questions

What data format is needed?

A square matrix where rows and columns are the same entities and cell values represent the flow or relationship strength between them.

Can I highlight specific connections?

Yes — hover or click on an entity to isolate its chords and dim the rest for focused analysis.

How many entities can I show?

Chord diagrams work well with 5–20 entities. Beyond that, consider filtering to top connections to maintain readability.

Related Chart Types

Ready-Made Chord Diagram Templates

Skip the blank canvas — open a free, editable Chord Diagram template, swap in your own data, and export. Browse all templates.

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