Compare software

D2 vs Mermaid: catalog facts
D2	Mermaid
Free Free and open source under the Mozilla Public License 2.0.	Free Free and open source under the MIT licence.
Windows, Command line	Web, Command line
Diagrams as text that fit into version control Simple syntax with automatic layout	Diagrams are plain text, so they diff and review like code Rendered natively by GitHub, GitLab and most documentation generators
Requires learning the D2 syntax Less fine control than drawing by hand	Layout is automatic, so fine control over positioning is limited Complex diagrams become hard to read in source form
Downloadable app	Web application, Downloadable app
Open source	Open source
License: MPL-2.0	License: MIT
No account needed	Not stated if an account is needed
Works offline	Not stated if it works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked September 22, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.