Comparison

MermaidEditor vs Prompt 3

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

Head to head
About

MermaidEditor

Create and edit diagrams and charts using mermaid-js syntax with real-time preview. Export your creations as PNG or SVG files and share them across all your Apple devices.

Highlights
  • Mermaid-js syntax highlighting
  • Code completion
  • Instant preview
  • Export to PNG/SVG
  • Cross-device editing
  • QuickLook preview extension
Features
Read full description

MermaidEditor is a diagram and chart editor, powered by mermaid-js. And MermaidEditor supports iPhone, iPad and Mac, with one app you can edit diagram everywhere on any device. MermaidEditor supports mermaid-js syntax highlighting and code completion, so it can help writing diagram and chart clearly, easily and quickly. You can also easily export charts as PNG images or SVG files from the editor, or share image to other people with system actions. √ All Platforms - Both Mobile and Desktop platforms supported, you can edit diagram documents on iPhone, iPad or Mac - Document browser based app, easily edit files on device and sync document between devices - Multiple windows ready, it makes the editor more powerful on iPadOS - Keyboard shortcuts ready on iPadOS with keyboard connected √ Powerful Editor - Syntax Highlighting for mermaid-js grammar - Auto Completion in editor helps typing keywords quickly - Code Snippets likes parallel block in sequence diagram makes life easier - Instant Parsing Error indicator for locating syntax error √ Instant Preview - Auto Generated Preview when typing in editor - Zoom and Pan to move preview for checking diagram's detail - With Scroll wheel it can be easily zoom diagram on macOS √ Integrated Extensions - Thumbnail support, every .mmd file will has its own thumbnail when saving file - QuickLook Preview extension helps you preview mermaid document in Files app on iPhone or iPad and Finder on macOS √ Sharing - Save diagram document as its source with .mmd extension - Export diagram to PNG image or SVG file with one click For mermaid-js grammar, please visit https://mermaid-js.github.io/mermaid/ for documentation.

About

Prompt 3

A fully-native terminal emulator for Apple devices, offering robust connectivity for SSH, Mosh, and more. It features fast emulation, customizable clips, secure authentication, and cross-device syncing for a seamless experience.

Highlights
  • Native terminal emulator
  • SSH, Mosh, Eternal Terminal, Telnet support
  • Panic Sync for cross-device server syncing
  • Superfast emulation with GPU acceleration
  • Customizable clips for commands
  • FaceID/TouchID authentication
  • Jump Hosts and Agent Forwarding
Features
Read full description

Prompt 3 is our #1 fully-native terminal emulator for Mac, iPhone, iPad, and now, Apple Vision Pro! Yes, with one purchase, you get four platforms.  Supporting SSH, Mosh, Eternal Terminal, Telnet, and Local Shells (on Mac), you can stay connected even on the most unstable networks. And with Panic Sync, your servers sync everywhere. For terminals, this is the only app you need. NOW EVEN BETTER: • SSH, Telnet, and Local (for Mac) Rock-solid and reliable connectivity to your hosts. • Mosh and Eternal Terminal Keep your terminal open even when you get disconnected. Mosh is optimized for high-latency, low-throughput networks. Eternal Terminal is great for when you need to keep your full terminal history on a flaky connection. • Lower Price Everything is so expensive right now. So we made Prompt cheaper. Take that, capitalism. • Superfast Emulation We retooled the text engine in Prompt 3 to be up to 10x faster, including GPU acceleration, and with improved terminal emulation, you can run nvim inside tmux without breaking a sweat. • Clips Put your most-used commands and text bits into clips and access them with a single tap via Prompt’s keyboard bar. Clips can be stored globally or per-server. • Secure Enclave Authenticate with FaceID and TouchID. The keys will stay secure on your device. • Panic Sync Sync your favorite servers, passwords, private keys, and clips, between Prompt on all of your devices. • Customizable Make Prompt perfect with new themes, fonts, and a very configurable iOS keyboard. • Jump Hosts and Agent Forwarding Access corporate servers, even at the beach. • Mouse Support Use your mouse to interact with TUI-based apps that run through the terminal. AND YES, A DARK ICON. What more can we say? TAKE CONTROL FROM ANYWHERE, INCLUDING YOUR MAC AND APPLE VISION PRO. WE HOPE YOU ENJOY PROMPT 3. © Panic EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

MermaidEditor3 screens
Prompt 34 screens

Verdict

The call

The clearest difference is price: Prompt 3 at Free against MermaidEditor's $3.99. Prompt 3 also leads on rating (4.3 vs 2.3) and ratings volume (376 vs 10). MermaidEditor's advantage is in-app purchases (none vs 2) and update cadence (every 3 weeks vs every 6 weeks). On review sentiment, ads, 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

Prompt 3 is free to download; MermaidEditor costs $3.99 up front. Prompt 3 sells 2 in-app purchases, starting at $9.99 per year. MermaidEditor asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Prompt 3 holds the better App Store score, 4.3 against 2.3. That said, the two scores are not equally well evidenced: Prompt 3 has 376 ratings behind it against 10, so its average is the more settled of the two. Written reviews point the same way: 14% of MermaidEditor's written reviews are positive against 22% of Prompt 3's.

UpkeepUpdate frequency

MermaidEditor ships an update every 3 weeks, Prompt 3 every 6 weeks. Both last shipped on October 27, 2026.

Scorecard7 real differences · 4 level
MermaidEditor versus Prompt 3: the parameters behind the verdict, then further details
ParameterMermaidEditorPrompt 3
Price$3.99Free — better
Rating2.3 (10 ratings)4.3 (376 ratings) — better
Positive reviews13.8% of reviews21.7% of reviews — better
Number of ratings10376 — better
Update frequencyEvery 3 weeks — betterEvery 6 weeks
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidPaid
Best chart rank#116#26 — better
DevicesiPhone, iPad, iPod, MaciPhone, iPad, Mac, Vision Pro
Requires iOS14.0 — better26.0
Further details — not scored
Size125 MB46 MB
Age rating4+4+
Developer基伟 徐Panic, Inc.

Customer experience

MermaidEditor

All ratings10 ratings
Positive30.0%
Neutral0.0%
Negative70.0%
Written reviews29 reviews
Positive13.8%
Neutral13.8%
Negative72.4%

Prompt 3

All ratings372 ratings
Positive82.5%
Neutral3.2%
Negative14.2%
Written reviews152 reviews
Positive21.7%
Neutral19.1%
Negative59.2%

Bugs and requests

MermaidEditor

Not enough reviews yet to summarise bugs or requests.

Prompt 3

Reported bugs

5 issues
  • Server list randomly disappears with Panic Sync
  • Crashes when connected to external monitor
  • Black screen issues with custom font configurations
  • Sync issues causing data loss
  • Vertical display sync issues

Requested features

8 requests
  • Shortcuts support on macOS
  • Ability to click and select within commands
  • Local shell option
  • Run clips on server connection
  • Export/backup clips
Show 3 more
  • Alt/Meta key support for Emacs
  • iCloud sync option
  • Sign in with Apple for Panic Sync

In-app purchases

None

MermaidEditor

No in-app purchases

2 purchases

Prompt 3

Subscriptions1
  • Prompt 3 iOS + Mac (Annual)7 Days trial$9.991 Year
One-time1
  • Prompt 3 One Time$49.99

Questions

Is MermaidEditor free?
MermaidEditor costs $3.99, with no in-app purchases.
Is Prompt 3 free?
Prompt 3 is free to download, with in-app purchases available.
Which has better reviews, MermaidEditor or Prompt 3?
Prompt 3 is rated higher. MermaidEditor averages 2.3 out of 5 from 10 ratings, while Prompt 3 averages 4.3 from 376 ratings.
Do MermaidEditor or Prompt 3 have ads?
Neither MermaidEditor nor Prompt 3 shows ads.
Which is updated more often, MermaidEditor or Prompt 3?
MermaidEditor ships an update every 3 weeks, and Prompt 3 every 6 weeks. Most recently, MermaidEditor was updated on October 27, 2026 and Prompt 3 on October 27, 2026.
Which is more popular, MermaidEditor or Prompt 3?
MermaidEditor currently peaks at #116 in the App Store charts, and Prompt 3 at #26. Chart position reflects recent download velocity rather than total install base.

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