Free Sequence Diagram Generator

Create UML sequence diagrams instantly with our free AI generator. Design API flows, authentication sequences, and system interactions in seconds.

Sequence diagram of the process to create a new social media account

Sequence diagram of the process to troubleshoot a computer not turning on

Sequence diagram of the process to plan a vacation trip

Sequence diagram of the process to handle customer complaints

Sequence diagram of the process to onboard new employees

What is a Sequence Diagram?

A sequence diagram is a UML diagram that shows how objects or systems interact over time. It visualizes the order of messages exchanged between participants—making it easy to understand complex processes step by step.

Sequence diagrams help you:

Document interactions — Show how components communicate in order
Design APIs — Plan request/response flows before coding
Debug issues — Trace message sequences to find problems
Communicate architecture — Explain system behavior to team members

Essential for software development, sequence diagrams turn abstract interactions into clear, time-ordered visualizations that developers and stakeholders can quickly understand.

Sequence Diagram Components

Actors and Objects (Lifelines)

Vertical dashed lines representing participants in the interaction. Actors are external users; objects are system components like servers, databases, or services.

Messages (Arrows)

Horizontal arrows showing communication between lifelines. Solid arrows represent synchronous calls (wait for response); dashed arrows show responses or asynchronous messages.

Activation Bars

Thin rectangles on lifelines showing when an object is actively processing. Helps visualize which component is "doing work" at each moment.

Loops and Conditionals

Frames around message groups indicating repetition (loop), conditions (alt/opt), or parallel execution (par). Essential for showing complex logic flows.

Our AI generator handles all these elements automatically—just describe your interaction flow.

Common Sequence Diagram Examples

User Authentication Flow

User, browser, auth server, and database interactions for login. Shows credential validation, token generation, and session creation.

API Request/Response

Client application calling a REST API. Visualize request handling, data retrieval, transformation, and response formatting.

E-commerce Order Processing

Customer, web app, inventory service, payment gateway, and notification service. Track the complete order lifecycle.

Microservices Communication

Service-to-service interactions in distributed systems. Document how services coordinate to fulfill requests.

Describe any of these scenarios to our AI generator and get a complete UML sequence diagram instantly.

Create Sequence Diagrams with AI

Skip the manual diagram tools. Describe your interaction flow and let AI generate a complete UML sequence diagram.

How it works:

Describe your flow: "User login sequence with browser, auth server, and database. Include password validation and JWT token generation."
AI generates the sequence diagram with proper UML notation
Download in high resolution for documentation

Better than traditional tools:

No PlantUML syntax to learn
No Mermaid code to write
No draw.io shapes to arrange
Just describe what happens and get your diagram

Create Sequence Diagram with AI →

Frequently Asked Questions

One Diagram. Different Styles.

Don't settle for generic visuals. Match your diagram's aesthetic to your brand identity with our Style Picker.

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Free Sequence Diagram Generator

What is a Sequence Diagram?