The Best UMLet Alternatives in 2026

PlantText provides an online editor for PlantUML code and generates class, sequence, activity, and state diagrams.

SankeyMATIC builds flow diagrams for comparing quantities across stages, with examples covering budgets, results, and processes.

Kroki provides one API for generating diagrams from textual descriptions using libraries such as Mermaid, PlantUML, Graphviz, and D2.

text2diagram creates diagrams and charts from text descriptions, with real-time collaboration and document permissions listed on its page.

Kroki CLI converts diagram files through the Kroki service, inferring diagram type from the file extension by default.

Dia is free, open source drawing software for structured diagrams, with downloads, shapes, and documentation.

Swimlanes.io creates sequence diagrams from text in a browser and lets users download diagrams or share them through links.

JDL-Studio draws UML diagrams from JDL syntax and provides instant feedback with customizable styling.

Mermaid generates diagrams such as flowcharts and sequence diagrams from text using syntax similar to Markdown.

PlantUML generates UML and other diagrams from textual descriptions and exports results in formats including PNG, SVG, and PDF.

DiagramGPT generates diagrams from text prompts, with the project page describing diagram workflows for teams.

Graphviz creates diagrams from graph descriptions and provides open-source software for visualizing structural information.

Mermaid Live Editor creates charts and diagrams from text using Mermaid’s markdown-like syntax in a browser.

Flowchart Fun converts text into flowcharts, mind maps, and process diagrams through an online text-based editor.

In a browser, yEd Live supports diagram creation, import, editing, and automatic arrangement for free.

Tree generates ASCII diagrams of folder structures as a browser utility written in TypeScript and React.

Cascii Core builds ASCII and Unicode diagrams in a browser using vanilla JavaScript, without server or library dependencies.

Flowchart Fun generates flowcharts and diagrams from text through a web application.

draw.io provides a free, open source application for creating diagrams, with storage options chosen by each team.

Svgbob converts text-based ASCII diagrams into SVG graphics, with both a library and command-line interface.

RAWGraphs App provides a web interface for creating custom vector-based visualizations with the RAWGraphs core.

Pie Chart Maker creates customizable pie charts and lets users download them as JPG, PNG, or SVG files.

Bar, line, area, and scatter charts can be created with dimple, an open-source charting API for D3.js.

Free open-source software for network visualization and analysis, with a desktop app and browser-based Gephi Lite for exploring graphs.