Preview Mermaid diagrams from AI chats like ChatGPT & Claude. Auto-renders flowcharts.
Users
146
+20 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
7
0 in 30 days
Store rank
#73K
#61K among extensions
Version
1.1.5
updated 9 Apr 2026
Users
monthly, 6 months
Latest, 18 Oct 2026:146 usersMove the mouse over the chart for any month
Ratings count
monthly, 6 months
Latest, 18 Oct 2026:7 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About Simple Mermaid Preview
Mermaid diagram viewer and renderer for Chrome. Simple Mermaid Preview automatically detects and renders Mermaid diagrams — flowcharts, sequence diagrams and other diagrams
Works on AI chat tools, code repositories, wikis, note-taking apps, and any blog or documentation site that embeds Mermaid code blocks.
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FEATURES
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🌐 Allowed Sites manager — add/remove domains for auto-render (with explicit permission prompt)
🖼️ Live rendering of Mermaid code blocks into visual charts
🔎 Pan & zoom — drag to explore large diagrams, pinch to zoom, one-click reset
🔀 Toggle between rendered diagram and raw Mermaid source code per diagram
🎛️ Global on/off switch and auto-render toggle in the popup
🔒 100% local rendering — uses bundled Mermaid.js, no internet connection required
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WHY INSTALL THIS?
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AI assistants frequently output Mermaid diagrams as raw code which saves you token than other output. Without a renderer, you see walls of text instead of the actual diagram. Simple Mermaid Preview fixes this — the diagram renders right inside the chat, no copy-pasting to mermaid.live or any external tool needed.
Developers reading pull requests, wikis, or documentation pages with embedded Mermaid diagrams also benefit — every diagram renders inline, instantly.
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PERMISSIONS MODEL
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By default, the extension auto-renders on:
- https://chat.openai.com/*
- https://chatgpt.com/*
- https://claude.ai/*
- https://gemini.google.com/*
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PRIVACY
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🚫 No data collection. No external servers. No account required. The extension stores only two preference toggles (enabled / auto-render) in chrome.storage.sync on your own Google account. All diagram rendering happens locally in your browser.