Mermaid Sketches Live Editor

2D Graphics

Free
No Download/Install required
No registration

The Mermaid Live Editor renders complex diagrams and visualizations from Markdown-inspired text scripts and Mermaid format. It provides a real-time environment for generating diverse schema types, including flowcharts, sequence diagrams, Gantt charts, and specialized visualizations such as Sankey diagrams, XY charts, and C4 architecture models.

Several similar tools online, but this one is very convenient, especially with the many examples on the bottom left corner.

Tip: the export function works good (PNG, PDF, SVG, and MMD with a choice of backgrounds) although in some sketches the adaptative zoom was framing a huge zone making the useful part microscopic (some non-visible element somewhere?).

Engineering, science, and quality professionals can typically use this tool to create technical documentation, architectural logic or diagrams to:

Visualize production workflows and standard operating procedures for quality compliance
Map experimental data flows and decision trees for scientific troubleshooting
Coordinate research and development milestones using script-generated Gantt charts

Disciplines: Software engineering, Technical writing, DevOps, Systems engineering, Project management.

Free alternative to Microsoft Visio, Lucidchart, PlantUML.

Mermaid Sketches Live Editor compared with Microsoft Visio, Lucidchart and PlantUML
Mermaid Sketches Live Editor	Microsoft Visio	Lucidchart	PlantUML
Authoring approach and diagram scope: Diagrams are written as Markdown-inspired text and rendered live in the browser. The site lists 33 diagram types and offers templates and examples to start from.	Authoring approach and diagram scope: Visio Plan 1 adds extra templates, stencils and shapes and UML 2.5 support. Plan 2 adds Power Automate export, database reverse engineering and better AutoCAD support.	Authoring approach and diagram scope: Lucidchart has a diagram as code editor for Mermaid with 11 supported types, including flowchart, sequence, Gantt, C4 and XY chart. A diagram generated from code must be changed by editing the code.	Authoring approach and diagram scope: PlantUML builds UML diagrams from text. Its FAQ calls it a drawing tool rather than a modeling tool, because it does not block inconsistent diagrams. Types include sequence, class, activity, state, deployment, Gantt, mind map and network diagrams.
Licence and cost model: The editor, templates, live preview, link sharing and exports are described as free, and no account is mentioned.	Licence and cost model: Subscription plans (Plan 1 and Plan 2), Visio included with eligible commercial Microsoft 365 subscriptions, and one-time purchase on-premises editions (Standard 2021 and Professional 2021).	Licence and cost model: A free plan exists with limits on editable documents and on objects per document, according to Lucid community staff. Paid Individual, Team and Enterprise plans include the Mermaid feature.	Licence and cost model: Free software under the GNU GPL version 3 or later. A paid option removes sponsored messages that may appear on welcome or error images. Generated images belong to the author of the source text.
Platform and installation: Runs in a web browser with no local installation. The upstream project can also be run locally with Docker.	Platform and installation: The web version is included in the plans and Microsoft Teams is supported. The Plan 2 desktop app is listed for Windows 11, 10, 8.1 and Windows Server 2019 and 2016, on up to five PCs per person.		Platform and installation: PlantUML runs as a Java JAR. Graphviz is used for some diagram types, and fontconfig may be needed on servers without fonts.
Openness, export and data handling: Exports are PNG, SVG, PDF and MMD source. The site says content is processed in the browser. The upstream repository mermaid-js/mermaid-live-editor is MIT licensed, but the site at this address does not state its own licence or affiliation.			Openness, export and data handling: Output formats include PNG, SVG and EPS, and PNG files embed the source text. The public server does not store diagrams, but traffic is plain HTTP, so the FAQ recommends a local server for sensitive diagrams.

Privacy: we have no feedback of potential problem with this tool and author. But like many online services, you are here providing them with your own data. Depending of the criticity of your data, this is your responsibility to assess author's reputation and potential misusage, and to check and accept their terms and conditions, or not.