About Mermaid Preview

Mermaid Preview is an independent, ad-supported developer utility. The goal is simple: a fast, accurate, privacy-respecting way to render Mermaid diagrams — paired with short, honest explanations of each diagram type so you can learn while you sketch.

What makes this different

• No ads inside the editor. The preview tool's first fold is the editor. Ads, if any, sit below the fold or on the guides.
• Rendering happens on your device. Mermaid.js runs in your browser; there is no server in the loop.
• Each diagram type comes with a guide. If you're not sure when to reach for a sequence diagram versus a flowchart, we'd rather give you a five-minute read than send you back to search results.
• Strict-mode rendering. Mermaid is initialised with securityLevel: 'strict', so pasted snippets cannot inject scripts into the page.

Who runs this

Mermaid Preview is a one-person project operated from South Korea as part of a portfolio of small, focused web utilities. It is not affiliated with the Mermaid project, GitHub, or any specific documentation tool. To get in touch, use the contact page or email facered79@gmail.com.

How it's built

The site is a static Astro build served by Nginx on an Oracle Cloud Always Free instance. The Mermaid library is bundled at build time and lazy-loaded only on the preview page, so the rest of the site stays light. There is no user account, no tracking pixel for your diagrams, and no server-side analytics of your input. See the Privacy Policy for the full picture.

Roadmap in brief

• Live preview with theme picker, SVG/PNG export, and share URL — available now
• Per-type landing pages and cheat sheets for the eight most-used Mermaid diagrams — in progress
• Guides and glossary for diagrams-as-code workflows — in progress
• Optional server-side rendering API for large diagrams (10 000+ nodes) — later
• Short share links (mermaid.aidalabs.kr/s/<id>) — later

Support the project

If this tool saves you time, the best thing you can do is link to it from a teammate's PR or share a guide on social media. Ad revenue funds the server bill; word of mouth funds the motivation.