Free Online Diagram Tool
Beautiful flow diagrams for your API in seconds
Visualize API workflows as clear and simple flow diagrams that can be shared with customers straight away. Completely free — no signup required.
Your Online Diagram Tool
Criteria Diagrams is a free tool for creating API flow diagrams.
- Create in seconds
- Anyone can use the drag-and-drop editor without having to learn a new markup language.
- Beautiful out-of-the-box
- Skip hiring a designer and share professionally-designed assets with customers straight away.
- Export for the web
- Download diagrams as PNG or SVG images, optimized for the web
- API-first
- Automatically generate flows from your API's requests and responses when you import your OpenAPI definition.
- Docs integrationsComing Soon
- Embed a live, interactive view in your docs. Integrations with Markdown-based docs like Readme and Docusaurus.
- Diagrams-as-code (DSL)Coming Soon
- Use your codebase your the source of truth with a Markdown-compatible DSL.
- Fully customizableComing Soon
- Match your company's brand colors and look and feel
- Free to use
- Create diagrams now, no need to create an account.
Try it out
Get started with these examples
Customize a pre-built template or start from a blank diagram.
Describes the sequence of OAuth 2.0 interactions between a user, web application, authorization server and resource server using the Authorization Code flow.
Describes the sequence of calls between a frontend, backend and API to verify a customer.
A new activity diagram with a client and server.
A new sequence diagram with a client and server.