Comparison

Mermaid Editor vs Happier

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Mermaid Editor

Create and visualize complex diagrams on your mobile device with a powerful editor. Supports real-time previews, syntax highlighting, and a wide range of chart types. Export your work in various formats and manage files locally.

Highlights
  • Real-time live preview
  • Full syntax highlighting
  • Support for all chart types
  • Template gallery for learning
  • Powerful file management
  • Professional export options
  • Offline mode support
Features
Read full description

Bring your ideas to life with the power of Mermaid Live Editor - anytime, anywhere. Whether you are a developer mapping out system architecture, a student visualizing logic, or a project manager building Gantt charts, Mermaid Live Editor is the ultimate mobile workspace for Mermaid diagrams. No more waiting to get back to your desk; write code and visualize complex charts directly on your phone with a seamless, high-performance editor. Key Features: - Real-Time Live Preview: See your diagrams take shape as you type. Our split-screen or toggle view ensures your visual logic matches your code instantly. - Full Syntax Highlighting: Write clean, readable code with an editor designed specifically for Mermaid syntax. - Support for All Chart Types: Flowchart, Sequence Diagram, Class Diagram, State Diagram, Entity Relationship Diagram, User Journey, Gantt, Pie Chart, Quadrant Chart, Requirement Diagram, GitGraph Diagram, C4 Diagram, Mindmap, Timeline, Zenuml, Sankey, XYChart Diagram, Block Diagram, Packet Diagram, Kanban Diagram, Architecture Diagram, Radar Diagram, Treemap Diagram. - Learn & Template Gallery: New to Mermaid? Browse our library of examples to learn the syntax and kickstart your projects with one tap. - Powerful File Management: Open, edit, and save .mmd files directly. Keep your workflow consistent across your mobile and desktop environments. - Professional Exports: Share your work in high resolution. Export your diagrams in PNG, JPEG, WebP, SVG, or PDF formats. - Offline Mode Support: No internet? No problem. Generate and preview diagrams locally without needing a network connection. Why Choose Mermaid Live Editor? - Speed: Light-weight and optimized for mobile performance. - Versatility: Perfect for documentation, software design, and business presentations. - Privacy: Your data stays on your device. Turn complex thoughts into beautiful diagrams with Mermaid Chart Editor. Download now and start creating! Term of Use: https://termux-studio.org/terms-of-use?name=Mermaid Privacy Policy: https://termux-studio.org/privacy-policy?name=Mermaid

About

Happier

This app acts as a secure bridge for AI coding agents, allowing you to run and continue sessions from your computer on your phone. It supports collaboration, reliable session resuming, and full history access with end-to-end encryption.

Highlights
  • Collaborative coding sessions
  • Support for multiple AI providers
  • Persistent and resumable sessions
  • Seamless switching between devices
  • End-to-end encryption
  • Infinite message history
Features
Read full description

Happier is an open-source, end-to-end encrypted companion app for AI coding agents: Claude Code, Codex, OpenCode, Cursor, Pi, Grok, Gemini, Copilot, Qwen, Kimi, Kilo, Kiro, Auggie. Run sessions on your computer, and continue them from your phone. Use our desktop app or web app, and truly start working from anywhere. YOUR EXISTING SESSIONS? ALREADY THERE. Open any Claude Code, Codex or OpenCode session running on your computer — live, from your phone. Nothing to migrate, nothing to learn. APPROVE FROM ANYWHERE Your agent asks to run a command and you get a push notification with Allow and Deny on it. Sessions waiting on a decision rise to a "Needs attention" group at the top of your list; everything still running gathers under "Working". REVIEW THE DIFF. SEND NOTES TO YOUR AGENTS. Browse every line your agent changed. Mark the exact lines you want addressed, choose which notes to send, and hand them straight back — same session, or a new one. EDITOR. GIT. TERMINAL. ONE TAP AWAY. Chat, files, Git and a live terminal, each its own tab. Open a file to read or edit it, review the diff, manage branches and open a pull request. YOU LOVE THE TERMINAL? WE DO TOO. If you want, you can keep running Claude Code, Codex or OpenCode in their native TUI. Happier mirrors them to every device, so you can follow along, send messages and approve permissions from anywhere — and switch between the terminal and Happier whenever you like. A COLLEAGUE YOU CAN TALK TO The voice assistant watches every running session. Brainstorm the next change, approve a permission or send a message, without picking up the phone. YOUR SESSIONS WORK AS A TEAM A session can start another session, send it messages and read its transcript — so a Claude session and a Codex session can split the work between them. Each one still runs its own subagents, on whichever backend you choose. USE THE SUBSCRIPTIONS YOU ALREADY PAY FOR Happier reuses the subscriptions and logins your existing CLIs already use — Claude, Codex, Cursor, Gemini, OpenCode. No new bill, no double billing, and Happier sells no AI of its own. POOL YOUR ACCOUNTS. KEEP THE SESSION GOING. Link accounts you own into a pool and watch usage and quota resets for every one of them in the app. Nothing switches until you build a pool — once you have, Claude Code and Codex sessions can change account without stopping, moving to whichever member has the most quota left, at most once a turn and never past a reset time the provider has published. OPEN SOURCE. END-TO-END ENCRYPTED. Your messages, prompts and session content are encrypted on your device before they reach a server: AES-256-GCM under a key drawn for that one session, sealed to an account key that is created on a device and never leaves your devices. The relay stores ciphertext and has nothing to open it with. Put the relay on your own hardware with one command — happier relay host install — or reach your computer over Tailscale and use no relay at all. FREE, AND MIT LICENSED The CLI, the mobile apps, the desktop app, the web app and the relay. No seat count, no trial, no feature gate. github.com/happier-dev/happier HOW TO START 1. On your computer: curl -fsSL https://happier.dev/install | bash (Windows: iwr https://happier.dev/install.ps1 -useb | iex) 2. Scan the QR code your terminal prints, with this app. 3. Start a session from the app, or run "happier claude" or "happier codex" in your terminal. REQUIRES A COMPUTER Happier is the client for agents running somewhere you control. It does not run an agent in the cloud, and your repository is never copied to us: the agent reads and writes files on the computer it runs on, and that computer stays the only full copy. Not affiliated with, or endorsed by, Anthropic, Google, GitHub or Cursor.

Screenshots

Mermaid Editor4 screens
Happier4 screens

Verdict

The call

The clearest difference is in-app purchases: Happier at none against Mermaid Editor's 3. Happier also leads on ads (none vs shown) and review sentiment (71% vs 50%). Mermaid Editor's advantage is update cadence (every 5 days vs every 5 weeks) and rating (4.7 vs 4.4). On price, ratings volume, monetization model and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Mermaid Editor sells 3 in-app purchases, starting at $2.99 per month. Happier asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Mermaid Editor holds the better App Store score, 4.7 against 4.4. Both are backed by a comparable volume of ratings — 13 and 16 respectively. Written reviews complicate that: 50% of Mermaid Editor's written reviews are positive against 71% of Happier's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Mermaid Editor ships an update every 5 days, Happier every 5 weeks. Both last shipped on October 28, 2026.

Scorecard7 real differences · 4 level
Mermaid Editor versus Happier: the parameters behind the verdict, then further details
ParameterMermaid EditorHappier
PriceFreeFree
Rating4.7 (13 ratings) — better4.4 (16 ratings)
Positive reviews50.0% of reviews71.4% of reviews — better
Number of ratings1316 — better
Update frequencyEvery 5 days — betterEvery 5 weeks
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFreeFree
Best chart rank—#173 — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better16.0
Further details — not scored
Size40 MB150 MB
Age rating4+4+
DeveloperTERMUX LIMITED LIABILITY COMPANYLeeroy Brun

Customer experience

Mermaid Editor

All ratings12 ratings
Positive91.7%
Neutral0.0%
Negative8.3%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

Happier

All ratings15 ratings
Positive86.7%
Neutral0.0%
Negative13.3%
Written reviews7 reviews
Positive71.4%
Neutral0.0%
Negative28.6%

In-app purchases

3 purchases

Mermaid Editor

Subscriptions2
  • Mermaid Pro Monthly$2.991 Month
  • Mermaid Pro$12.991 Year
One-time1
  • Mermaid Lifetime$34.99
None

Happier

No in-app purchases

Questions

Is Mermaid Editor free?
Mermaid Editor is free to download, with in-app purchases available.
Is Happier free?
Happier is free to download, with no in-app purchases.
Which has better reviews, Mermaid Editor or Happier?
Mermaid Editor is rated higher. Mermaid Editor averages 4.7 out of 5 from 13 ratings, while Happier averages 4.4 from 16 ratings.
Do Mermaid Editor or Happier have ads?
Mermaid Editor shows ads; Happier does not.
Which is updated more often, Mermaid Editor or Happier?
Mermaid Editor ships an update every 5 days, and Happier every 5 weeks. Most recently, Mermaid Editor was updated on October 28, 2026 and Happier on October 28, 2026.

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