Comparison

PrivyMermaid vs DevBuddy Dev Tools

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

Head to head
About

PrivyMermaid

This privacy-focused editor allows developers and technical writers to create, edit, and preview diagrams completely offline. Your sensitive data remains on your device, ensuring maximum security and control over your diagrams.

Highlights
  • 100% Private & Offline diagram editing
  • Instant offline diagram rendering
  • No cloud sync for enhanced data privacy
  • Live preview of diagram changes
  • Multiple theme selections
  • Full Mermaid syntax support
Features
Read full description

PrivyMermaid is a privacy-focused diagram editor for developers, technical writers, and teams who work with Mermaid and D2. Create, import, edit, organize, preview, and export diagrams on your iPhone or iPad. The Mermaid and D2 renderers are bundled in the app, so you can keep working without an internet connection. Your diagrams stay on your device by default; no diagram source is sent to a rendering service. Key Features: Mermaid + D2, fully offline Two diagram languages: Create and preview Mermaid or D2 diagrams, including flowcharts, sequence diagrams, Gantt charts, architecture diagrams, and more. Local rendering: Visualize diagrams without an internet connection. The rendering engines run in the app, not on a diagram server. Import and export: Work with Mermaid (.mmd) and D2 (.d2) source files, then export SVG, PNG, PDF, or GIF. Projects and templates Organize your work: Keep diagrams in native projects and switch between documents quickly. Built-in templates: Start from ready-made diagram examples, clearly labeled for Mermaid or D2. Live preview and themes: See manual edits immediately and choose a Mermaid or D2 theme plus your preferred preview background. Privacy on your terms Local by default: Diagrams are stored locally and no account is required for offline editing. Optional Diagram Cloud sync: If you choose to sign in, diagrams can sync to your Diagram Cloud account. Your local copy remains available offline. Why PrivyMermaid? Keep technical documentation close at hand without depending on a browser tab or a hosted rendering service. PrivyMermaid is a lightweight, private way to diagram on the go. Note: For AI-assisted Mermaid and D2 generation, questions, and fixes using your local LLM, check out PrivyMermaid Pro (in-app: tap the Pro tab or open the Pro panel; or download the separate PrivyMermaid Pro app).

About

DevBuddy Dev Tools

Features
Read full description

DevBuddy Tools puts 27 essential developer utilities in one fast mobile toolkit. Format, validate, encode, decode, generate, and test on the go with tools built for developers, QA engineers, DevOps teams, students, and technical support workflows. Whether you are checking JSON, testing regex, decoding JWTs, generating UUIDs, or converting Base64, DevBuddy helps you work faster without switching between multiple apps and websites. Featured tools include: • JSON Formatter and Validator • YAML ↔ JSON Converter • XML Formatter • SQL Formatter • Base64 Encoder and Decoder • URL Encoder and Decoder • HTML Entity Encoder and Decoder • Regex Tester • JWT Decoder • Hash Generator • UUID Generator • QR Generator • Timestamp Converter • Token Counter • TOTP Tester • Diff Tool • Number Base Converter • Color Picker • Lorem Ipsum Generator Why DevBuddy Tools: • 27 practical tools in one app • Built for quick developer workflows • Clean interface for iPhone and iPad • Handy for debugging, formatting, encoding, and test data generation • History and favorites for repeated use From API payload checks to text conversion and quick test utilities, DevBuddy Tools gives you a compact developer toolkit whenever you need it.

Screenshots

PrivyMermaid4 screens
DevBuddy Dev Tools4 screens

Verdict

The call

The clearest difference is in-app purchases: DevBuddy Dev Tools at none against PrivyMermaid's 2. DevBuddy Dev Tools also leads on iOS requirement (13.0 vs 17.0). On price, ads 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. PrivyMermaid sells 2 one-off in-app purchases. DevBuddy Dev Tools asks for nothing beyond the download.

Scorecard2 real differences · 6 level
PrivyMermaid versus DevBuddy Dev Tools: the parameters behind the verdict, then further details
ParameterPrivyMermaidDevBuddy Dev Tools
PriceFreeFree
Positive reviews100.0% of reviews—
Update frequencyEvery 2 weeks—
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree—
DevicesiPhone, iPad, MaciPhone, iPad, iPod
Requires iOS17.013.0 — better
Further details — not scored
Size39 MB32 MB
Age rating4+4+
DeveloperGUOYU WANGSahana A S

In-app purchases

2 purchases

PrivyMermaid

One-time2
  • PrivyMermaid Pro$4.99
  • PrivyMermaid Pro$9.99
None

DevBuddy Dev Tools

No in-app purchases

Questions

Is PrivyMermaid free?
PrivyMermaid is free to download, with in-app purchases available.
Is DevBuddy Dev Tools free?
DevBuddy Dev Tools is free to download, with no in-app purchases.
Do PrivyMermaid or DevBuddy Dev Tools have ads?
Neither PrivyMermaid nor DevBuddy Dev Tools shows ads.

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