Awesome Diagramming

A curated list of awesome diagramming tools available for software engineering teams. Feel free to contribute to this on-going list.

When diagrams are useful?

Diagrams are faster and compact way for knowledge transfer. It's much easier to convey system architechture with a diagram compared to writing an essay on it.

Diagrams are especially useful in providing high level overview of software design. Following are the most-widely used diagrams by engineering teams:

Sequence diagram - to visualize interaction between different components in a sequential order
System architecture diagram - to visualize system architecture
ER diagram - to visualize data models
Gantt diagram - used for project planning and timeline estimation

Factors to consider before choosing the diagramming tool

Free / Freemium / Paid
Open source or Closed source
Ease of use
Diagram as code vs Hand drawn
Visual Appearance - Modern / Minimalistic / Outdated / Hand-drawn

General Purpose (flexible for all kinds of diagrams)

Kroki (Free, Open Source, Diagram as code, Ease of use - Easy, Visual Appearance - Flexible).
Examples - Link
Mermaid (Free, Open Source, Diagram as code, Ease of use - Easy, Visual Appearance - Modern).
Examples - Link
Excalidraw (Freemium, Open Source, Hand drawn, Ease of use - Easy, Visual Appearance - Hand-drawn).
Examples - Link
PlantUML (Free, Open Source, Diagram as code, Ease of use - Intermediete, Visual Appearance - Outdated)
Examples - Link, Link
Draw.io (Free, Open Source (But Closed To Contribution), Hand drawn, Ease of use - Moderate, Visual Appearance - Modern).
Examples - Link
Nomnoml (Free, Open Source, Diagram as code. Ease of use - Easy, Visual Apperance - Minimalistic).
Examples - Link
Diagram.codes (Freemium, Closed Source, Diagram as code, Ease of use - Easy, Visual Appearance - Outdated).
Examples - Link
Lucidchart (Paid, Closed Source, Hand drawn, Ease of use - Easy, Visual Appearance - Modern).
Examples - Link
Blockdiag (Free, Open Source, Diagram as code, Ease of use - Easy, Visual Appearance - Outdated).
Exampes - Link

Others - Miro, Gliffy, Inkscape, Plectica, Whimsical, ZenUML, Gleek, Structurizr, StarUML, Whiteboards.io

Sequence diagram

Swimlanes (Free, Closed Source, Ease of use - Easy, Visual Appearance - Modern)
Examples - Link

Others - Websequencediagrams, Sequencediagram.org

System design diagram

Essential readings
C4 Model, 5 types of architecture diagrams

Diagrams (Free, Open Source, Ease of use - Easy, Visual Appearance - Modern).
Examples - Link
Terrastruct (Paid, Closed Source, Ease of use - Easy, Visual Appearance - Modern)
Examples - Link
IcePanel (Paid, Closed Source, Hand drawn, Ease of use - Easy, Visual Appearance - Modern) Examples - Link
Lucidscale (Paid, Closed Source, Ease of use - Intermediete, Visual Appearance - Modern).
Examples - Link

Others - Ilograph, Omnigraffle, Cloudcraft, CloudSkew

ER diagram

Essential Readings
How to choose your ERD?

DbDiagram (Freemium, Closed Source, Ease of use - Easy, Visual Appearance - Modern)
Examples - Link
Azimutt (Free, Open Source, Ease of use - Easy, Visual Appearance - Modern).
Examples - Link

Azimutt is useful when you want to visualize existing database
QuickDBD (Free, Closed Source, Ease of use - Easy, Visual Appearance - Modern).
Examples - Link

Others - DrawSql, ERD Plus, Creately, SqlDBM

Gantt Chart

Markwhen (Free, Open Source, Ease of use - Easy, Visual Appearance - Minimalist)
Examples - Link

gtanczyk/awesome-diagramming