Changelog
Track all the updates, new features, and improvements to SimpleMermaid
Current Version: 1.9.0
Welcome to the SimpleMermaid changelog. This page documents every update we ship, from major new features to subtle quality-of-life improvements. We believe in transparent development, so you can always see exactly what changed and why.
SimpleMermaid follows semantic versioning: major versions introduce significant new capabilities, minor versions add features and improvements, and patch versions fix bugs. We ship updates regularly based on community feedback and our own roadmap.
Pan around big diagrams, highlight what matters like on a whiteboard, pick a diagram theme, and export it all. Plus an important security fix.
New Features
- Right-drag to pan - Hold the right mouse button (or the middle one) and drag to move the diagram around. Click the zoom percentage to reset zoom and position
- Highlighter & pen - Press
D or click the highlighter button to draw on top of your diagram: highlighter, pen, eraser, six colors, undo/redo and clear. Drawings stay glued to the diagram through zoom and pan, and are remembered per tab
- Diagram themes - A new theme picker in the preview header: Auto (follows light/dark), or Mermaid's own Default, Neutral, Forest and Dark. Each diagram sits on a matching background and exports with it
- Export with drawings - PNG, SVG and PDF exports include your drawings; untick “Include my drawings” in the export dialog to leave them out
Security
- Fixed a cross-site scripting issue: crafted diagram text could run script through the editor's error message. Error text is now always shown as plain text
- Saved and imported diagrams are validated, and the saved-diagram list no longer builds HTML from stored names or ids
- Oversized share links are refused instead of freezing the tab
- Third-party scripts are version-pinned with integrity checks everywhere, jsPDF is updated to a patched release, and every page now ships a baseline Content Security Policy
Improvements
- Exported image and PDF sizes no longer change with the on-screen zoom level
- The example diagrams no longer rely on emoji, so they look the same on every device
A polish release: readable text in both themes, a PNG export fix, and better discoverability.
Bug Fixes
- PNG export hang - Exporting a User Journey diagram as PNG (or PDF) no longer hangs; its labels are now rendered safely for image export
- Readable Gantt charts - Done, active and critical task bars now keep readable text in light and dark themes (dark-theme "done" tasks were nearly invisible)
Improvements
- Higher-contrast muted text, links, buttons, toasts and the cookie banner in both light and dark themes
- Clearer page titles, richer link previews and an
llms.txt so search and AI tools can find and describe SimpleMermaid
An export release: the quick Export dropdown grew into a proper export dialog — same two clicks for the default flow, with new knobs when you need them.
New Features
- Export dialog - The Export button now opens a compact dialog with format tabs (PNG, SVG, PDF and new Markdown), a one-line hint per format, and a single big export button
- Markdown export - Download your diagram as a
.md file with a ready-to-paste mermaid code fence for GitHub, GitLab or Notion
- Export options - Collapsible "More options" with scale (1x/2x/3x), background (match theme, white, or transparent) and padding (0–100px). Transparent PNG finally works, and your choices are remembered for next time
- Smarter filenames - Exports are now named after your saved diagram (e.g.
simplemermaid-com-auth-flow.png) — or get a random geeky codename like simplemermaid-com-cosmic-kraken.svg if the diagram is unnamed
Improvements
- SVG exports now include a theme-matching background by default, so dark-theme diagrams no longer look broken on white pages (pick Transparent to restore the old behavior)
- PDF exports fill the whole page with the chosen background instead of leaving a white frame around dark diagrams
A findability and freshness release: the editor is now one click away the moment the homepage loads, and the rendering engine picks up Mermaid's newest diagram types.
New Features
- Start Creating, instantly - The homepage now shows the Start Creating button and a quick feature summary (64 templates, PNG/SVG/PDF export, 100% in your browser) right when it loads — no more scrolling to the end to find the editor
- New Mermaid diagram types - The editor runs Mermaid 11.16.1, and "Try in Editor" buttons now appear for all the latest diagram types: Venn, Ishikawa (fishbone), Swimlane, Railroad, Cynefin, Kanban, Packet, Architecture, Radar, and Treemap
Bug Fixes
- If the homepage's 3D scene can't load (blocked CDN, older graphics hardware), the page now falls back to a normal static layout instead of showing a blank screen
Under the hood
- Mermaid engine pinned to 11.16.1 (a security patch release) with subresource integrity verification
- Clearer editor page title and description for search results
A housekeeping release. SimpleMermaid is one of several free tools we build, and this update introduces a small, polite way to discover the others — plus a site-wide link audit that fixed a broken button on the Learn page.
New Features
- Discover our other projects - A small dismissable card occasionally appears in the corner introducing our sister sites (DefenseModeling, Military Aircraft Tracker, Legenderby). It waits until you've been on a page a while, shows at most once every 12 hours, never blocks content, and closing it keeps it away
Bug Fixes
- Fixed the "Try in Editor" button in the Advanced Styling section of the Learn page, which pointed to a dead local link instead of the editor
Under the hood
- Audited every internal link and asset reference across all pages — all now resolve correctly on the live site, on localhost, and offline
- The promo card is a single zero-dependency script (
promo.js), theme-aware in light and dark mode, and respects reduced-motion preferences
The editor got its biggest visual refresh since launch. The old three-row toolbar packed a dozen buttons into a cramped band that never quite matched the rest of the site. This release replaces it with a clean layout: a slim icon rail down the left for your tools, and a single, breathable toolbar up top for examples, export, and sharing. The whole editor now speaks the same indigo palette, rounded corners, and soft shadows as the landing page — one coherent product.
New Features
- Redesigned editor shell - A left icon rail (Save, My Diagrams, Clear, Layout, Theme) plus a single clean toolbar for the category/example pickers, Export, Copy, and Share
- Unified design language - Colors, radii, and shadows now match the SimpleMermaid landing page for a consistent look end to end
- Polished dark mode - The refreshed rail, toolbar, dropdowns, tabs, and dialogs all read cleanly in dark theme
- Crisp SVG icons - Toolbar icons are now sharp vector graphics with hover tooltips and accessible labels
Under the hood
- The redesign is a presentation-only reskin — the editor's core logic (tabs, sharing, examples, export) is untouched, so every existing share link and saved diagram keeps working
- Added a zero-dependency browser test suite (
tests.html) that drives the real editor and verifies sharing, tabs, theme, error handling, and diagram-type detection on every change
- Export (PNG/SVG/PDF) moved into a tidy dropdown; the info panel opens from the rail
Until now the editor was a plain textarea — readable, but every keyword and arrow looked the same as the surrounding text. This release brings real syntax highlighting to the code panel: diagram keywords, arrows, comments, and strings each get their own color, so the structure of a diagram is visible at a glance while you write it.
New Features
- Syntax-highlighted editor - Mermaid keywords, arrows, comments, strings, and numbers are color-coded as you type
- Theme-aware colors - Token colors automatically adapt to light and dark mode
- Smart indentation - Tab key inserts two spaces instead of jumping focus
Under the hood
- Editor migrated from
<textarea> to a contenteditable surface highlighted by Prism with a custom Mermaid grammar
- Caret position is preserved across re-highlight passes so typing feels stable
- Existing tab state, share links, examples, and export flows are unchanged
Tabs were the most requested feature since launch. Developers frequently need to reference one diagram while building another, comparing an existing architecture with a proposed change, or keeping a sequence diagram open alongside the class diagram it references. This release makes that workflow seamless.
New Features
- Editor Tabs - Work on multiple diagrams simultaneously with a tabbed editor interface
- Per-tab state - Each tab preserves its own zoom level, cursor position, and scroll position
- Tab persistence - All open tabs are saved to localStorage and restored on reload
- Inline tab rename - Double-click any tab to rename it
Improvements
- Loading an example renames the active tab to match
- Loading a saved diagram opens in a new tab
- Save modal pre-fills with the active tab name
- Shared diagrams open in a dedicated "Shared Diagram" tab
Keyboard Shortcuts
Ctrl+T — New tabCtrl+W — Close active tabCtrl+Tab / Ctrl+Shift+Tab — Cycle through tabs
We want to keep SimpleMermaid free and ad-free for everyone. Adding a Buy Me A Coffee link gives the community an optional way to support server hosting costs without us resorting to ads or paywalls.
New Features
- Buy Me A Coffee support - Help keep SimpleMermaid running ad-free by supporting server costs directly
Improvements
- Navigation hamburger menu now triggers at 1030px for better usability with extra nav items
New Features
- Zoom controls - Zoom in/out buttons (25%-200%) in preview panel header with click-to-reset percentage display
New Features
- Diagram stats display - Shows diagram type detection, node count, and edge count in real-time
- PDF export - Export diagrams to PDF format with automatic orientation detection
Bug Fixes
- Fixed dark mode text visibility issues in Journey diagrams
New Features
- Community Showcase diagrams - Added 3 new funny developer life diagrams (Stand-up Meeting Reality, Bug Life Cycle, Deploy Friday) contributed by emphonic.com
- New changelog page to track all updates and improvements
- "Recent Updates" section on landing page
Improvements
- Better organization of Community Showcase examples
- Enhanced footer navigation across all pages
New Features
- Zoom controls - Added zoom in/out/reset buttons for better diagram viewing
- Mouse wheel zoom support with Ctrl/Cmd modifier
- Pinch-to-zoom on touch devices
Improvements
- Better handling of large diagrams
- Improved responsive layout for mobile devices
New Features
- Community Showcase - New category for user-submitted diagrams
- Added Broadcast Studio diagram by Lemmur Production
- Added AWS Malware Scanning diagram by Vaishnav
Improvements
- Templates section on landing page now links directly to examples
- Better example categorization in dropdown menus
Bug Fixes
- Fixed dark theme rendering issues with certain Mermaid diagram types
- Fixed URL sharing when diagram contains special characters
- Improved error handling for invalid Mermaid syntax
Improvements
- Better syntax error messages with line numbers
- Faster diagram rendering performance
New Features
- Security & Threat Models category - 10 new security-focused diagram templates
- RBAC Model, Zero Trust Architecture, API Threats diagrams
- Kubernetes Threats, CI/CD DevSecOps, Supply Chain Attack templates
- Data Breach Flow and Incident Response diagrams
Improvements
- Expanded System Architecture category with new templates
- Better example organization with subcategories
- Improved landing page with use cases section
New Features
- Save & Load diagrams - Local storage support with auto-save
- Import/Export backup - Download and restore your diagrams
- Multiple saved diagrams management
- Diagram naming and organization
Improvements
- Auto-save every 30 seconds
- Better offline support
- Improved mobile layout
Features
- Live Mermaid editor with real-time preview
- Instant URL sharing with LZ-string compression
- Export to PNG/SVG for presentations and docs
- Light and dark theme support
- Horizontal and vertical layout modes
- 20+ built-in example templates
- Resizable editor panels
- Mobile-responsive design
- No account required - privacy focused
Development Roadmap
Here's what we're working on next. Our roadmap is shaped by community feedback, so if you have a feature request, we'd love to hear it.
Planned Features
- Collaborative Editing - Real-time collaboration using WebRTC, allowing multiple users to edit the same diagram simultaneously without any server-side storage.
- Custom Themes - Create and save custom color themes for your diagrams, with the ability to share theme presets via URL.
- Diagram Templates Library - An expanded template system with community-contributed templates organized by industry and use case.
- Keyboard Shortcuts Expansion - Additional shortcuts for common operations like undo/redo, find/replace within the editor, and quick diagram type switching.
- Embed Widget - A lightweight embed code that lets you include live, editable SimpleMermaid diagrams in your documentation, blog posts, or internal wikis.
Under Consideration
- VS Code Extension - A companion extension that integrates SimpleMermaid's preview capabilities directly into Visual Studio Code.
- Diagram Versioning - Track changes to your diagrams over time with a local version history and visual diff view.
- AI-Assisted Diagramming - Natural language to diagram conversion, allowing you to describe your system and generate a starting diagram automatically.
- Presentation Mode - A full-screen, distraction-free view optimized for presenting diagrams during meetings and design reviews.
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