Comparison

JSON Designer vs System Designer

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

Head to head
About

JSON Designer

Visually model and design JSON structures with this intuitive tool. Generate code from your models and export diagrams for documentation. Ideal for developers who want to understand and represent APIs more effectively.

Highlights
  • Graphically model JSON structures
  • Export JSON models as images
  • Reverse-generate models from JSON
  • Browse API examples
  • Generate Protocol Buffers (.proto)
  • Includes tutorial and open-in functionality
Features
Read full description

Start modeling - finally! your JSON visualization & design tool If you are new to the app: this app is out for a couple of years now and develpers greatly appreciate it. It is a design tool primarily, and has always been for free as my part of giving back to the developer community. I put some effort in a smoother design and made many adjustments from some valuable feedbacks. Code generators are a separate feature, which is connected to a payment, which is a practical way to show if you value the feature and the app itself. Depending on your feedback the app will be extended with further functionality. Enjoy JSON modeling! tl;dr: Modeling is the core feature and for free as always, code generators have to be paid for (and save lots of time) Despite the long existence of UML and best practices of software engineering you can't find any diagrams in the API documentations of Google, Facebook, Twitter and the likes. So help yourself, stop deciphering unreadable example files and use this new simplified visual representation of JSON structures as object oriented models. Methodology: • Tree structures depict hierarchical structures of objects • Multiplicity indicator of objects and attributes depict arrays Examples and a tutorial are provided inside the App. Use JSON Designer to jump right into defining your API, without reading a single page of JSON documentation. Features: • Graphically model JMs, ie your JSON Models • Export JM images to integrate in documentations • Reverse-generate JMs from URLs or direct JSON input • Browse hand-picked API examples • NEW Generate Protocol Buffers .proto for gRPC • Tutorial • Open-in: exchange JSON files with other apps Stay tuned for new features via @jsondesigner on Twitter. Feedback is gratefully appreciated. More that 65% of JSON Designer users say it's a must-have and are using it daily! Optional code generators for backers (saving you lots of time): Obj-C, Swift, Java, Kotlin, JavaScript, Perl, Python, Ruby, PHP. To back the app, show your gratitude and support further development, simply get the "I'm backing you" app subscription for a couple of month: This subscription brings you access to an extended and growing selection of code generators. It's a recurring monthly subscription, bringing you full access to all code generators for that time. The subscription is allocated as monthly 1.99$ payment. The subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. Your account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal. The subscription may be managed and auto-renewal may be turned off by going to your Account Settings after purchase. No cancellation of the current subscription is allowed during active subscription period. Any unused portion of a free trial period, if offered, will be forfeited when you purchase the subscription. In regards of subscriptions please review the terms of use and privacy policy on jsondesigner.com/privacyterms

About

System Designer

Design complex systems using a low-code platform that leverages UML standards. Generate code skeletons and manage components graphically. Run and test your system with dynamic type checking.

Highlights
  • UML-based system modeling
  • Code skeleton generation
  • Graphical component creation
  • MSON format for model definition
  • Dynamic type checking
  • Cross-device synchronization via GitHub
Features
Read full description

System Designer is a low-code development platform for creating systems. No matter the frameworks you use and the code you write, the most important is the model that you define to create your system. System Designer helps you to design this model and to generate the classes and components to build your system. DESIGN YOUR SYSTEM WITH EASE If you look at the different JavaScript frameworks on the market, you will notice that they all have their own way to define a model, generally only with code. System Designer uses UML, a standard, to define your model. So you probably already know how to design in System Designer even if you have never run it. The definition of the model is stored on a JSON format called MSON. With MSON you can define types, classes, one to one / one to many relationships and multi inheritance between classes. CODE THE BEHAVIOR OF YOUR SYSTEM Once you have created your model, System Designer generates the skeletons of all your methods. You only have then to add your code to implement them. System Designer provides you helpers to manage your components. You can easily navigate threw your components to create your application. CREATE COMPONENTS GRAPHICALLY There is no need to code to instantiate a component. Create a component in System Designer is like creating a document in a NoSQL Database. In fact, System Designer acts as an ODM (Object-Document Mapper) to manage your components as NoSQL Documents. RUN YOUR SYSTEM You can run your system directly from System Designer. Because you have defined a model for your application, a Dynamic Type Check is done on every action of your system. All warnings are send and shown in System Designer. DESIGN ON THE GO System Designer can be used on macOS, iPad or any browsers. System Designer has a Github module to synchronize your work between all these apps. You can begin your design on your Mac and then continue it on your iPad.

Screenshots

JSON Designer2 screens
System Designer3 screens

Verdict

The call

The clearest difference is rating: System Designer at 4.4 against JSON Designer's 3.3. System Designer also leads on in-app purchases (none vs 1) and review sentiment (78% vs 52%). JSON Designer's advantage is iOS requirement (11.0 vs 15.6). On price, ratings volume, 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. JSON Designer sells 1 in-app purchase, starting at $1.99 per month. System Designer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

System Designer holds the better App Store score, 4.4 against 3.3. Both are backed by a comparable volume of ratings — 10 and 17 respectively. Written reviews point the same way: 52% of JSON Designer's written reviews are positive against 78% of System Designer's.

UpkeepUpdate frequency

JSON Designer ships an update every 4 months, System Designer monthly. The most recent releases landed on June 10, 2026 and September 18, 2026 respectively.

Scorecard6 real differences · 4 level
JSON Designer versus System Designer: the parameters behind the verdict, then further details
ParameterJSON DesignerSystem Designer
PriceFreeFree
Rating3.3 (10 ratings)4.4 (17 ratings) — better
Positive reviews52.0% of reviews77.8% of reviews — better
Number of ratings1017 — better
Update frequencyEvery 4 monthsMonthly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS11.0 — better15.6
Further details — not scored
Size10 MB7 MB
Age rating4+4+
DeveloperCribster UG (haftungsbeschrankt)Erwan Carriou

Customer experience

JSON Designer

All ratings10 ratings
Positive40.0%
Neutral30.0%
Negative30.0%
Written reviews50 reviews
Positive52.0%
Neutral10.0%
Negative38.0%

System Designer

All ratings17 ratings
Positive88.2%
Neutral0.0%
Negative11.8%
Written reviews9 reviews
Positive77.8%
Neutral0.0%
Negative22.2%

In-app purchases

1 purchases

JSON Designer

Subscriptions1
  • App Backer - Code Generators Access$1.991 Month
None

System Designer

No in-app purchases

Questions

Is JSON Designer free?
JSON Designer is free to download, with in-app purchases available.
Is System Designer free?
System Designer is free to download, with no in-app purchases.
Which has better reviews, JSON Designer or System Designer?
System Designer is rated higher. JSON Designer averages 3.3 out of 5 from 10 ratings, while System Designer averages 4.4 from 17 ratings.
Do JSON Designer or System Designer have ads?
Neither JSON Designer nor System Designer shows ads.
Which is updated more often, JSON Designer or System Designer?
JSON Designer ships an update every 4 months, and System Designer monthly. Most recently, JSON Designer was updated on June 10, 2026 and System Designer on September 18, 2026.

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