Jayson vs Carnets
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Jayson
This app allows you to view and edit JSON files directly on your device. It offers features like tabbed browsing, split-screen comparisons, and integration with Siri Shortcuts and the Share Sheet for easy JSON parsing and management.
- Browse JSON files
- Table or syntax highlighted text view
- Tabbed interface
- Multiple splits for comparison
- Siri Shortcuts integration
- Share Sheet Actions
- URL schemes
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Jayson is a JSON viewer and editor for iPhone and iPad. Browse JSON as a structure, edit values, and save your changes back to the file. Whether you're inspecting an API response, checking a config file, or making a quick fix on the go, Jayson turns raw JSON into something you can actually read and change. BROWSE AND EDIT - Open JSON files stored on your device or in iCloud Drive. - Toggle between a structured table view and syntax highlighted text. - Add new values and keys, and save your changes back to the file. - Parse text or the contents of a URL from your clipboard into JSON. - Highlight a key from a child of an array to get a quick overview of your data. TABS, SPLITS, AND WINDOWS - Switch between files, or different objects in a single file, using tabs. - Compare JSON in a single file or across files using multiple splits. - Open multiple windows on the iPad. WORKS WITH SHORTCUTS Jayson integrates with Shortcuts, which comes in handy for debugging API calls, previewing JSON files, and building workflows around JSON. - Pass a response from Get Contents of URL to Jayson to see how it is structured. - Open JSON as a document you keep working on, or as a temporary preview. - Format JSON and hand the result to the next action, using spaces or tabs. FREE, WITH AN OPTIONAL UPGRADE Jayson's core functionality is free. Browsing, editing, saving, splits, Shortcuts, and working with up to two tabs at a time cost nothing. A one-time in-app purchase enables having more than two tabs open at once, switching between light and dark themes, and personalizing the app icon, accent color and type icons. One purchase, no subscription.
Carnets
This app offers a standalone Jupyter notebook environment for creating and running code snippets, combining them with text and Markdown. It includes pre-installed scientific packages and allows for offline use, making it ideal for education and research.
- Standalone Jupyter notebook implementation
- Embedded Python interpreter
- Offline functionality
- Pre-installed scientific packages
- Supports Jupyterlab
- Package installation via %pip
- Notebook sharing and opening
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Jupyter notebooks are a powerful tool used in education and research. You can write small snippets of Python code and observe the result on screen, combine with paragraphs of text, using Markdown. Carnets provides a complete, stand-alone, implementation of Jupyter notebooks. Everything runs on your device, using the embedded Python interpreter; you do not need an internet connection. You can chose between Jupyter notebooks and the more advance Jupyterlab using Settings. Numpy, Sympy, Matplotlib, Pandas, lxml, bokeh, nbextensions (including ipywidgets) and many other packages are pre-installed. To see the full list of installed packages, type "%pip list" in a code window. You can add more packages using "%pip install packageName", but only if they are pure Python. If you need scipy, seaborn or scikit-learn, please use our other App, "Carnets - Jupyter (with scipy)". You can share your notebooks with other apps and also open notebooks or directories managed by other apps. Partial list of installed packages: astropy, babel, bokeh, cryptography, cvxopt, Fiona, geopandas, geopy, lxml, matplotlib, numpy, openCV, pandas, pillow, pyFFTW, pyproj, rasterio, regex, shapely, sympy, wordcloud.
Screenshots
Verdict
The clearest difference is in-app purchases: Carnets at none against Jayson's 1. Carnets also leads on iOS requirement (14.0 vs 26.0). On price, rating, review sentiment and ratings volume 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
Both are free to download. Jayson sells 1 one-off in-app purchase. Carnets asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.5 for Jayson against 4.6 for Carnets. Both are backed by a comparable volume of ratings — 425 and 316 respectively. Written reviews are what separate them: 81% of Jayson's written reviews are positive against 78% of Carnets's.
Jayson ships an update every 3 weeks, Carnets monthly. The most recent releases landed on September 23, 2026 and September 24, 2026 respectively.
| Parameter | Jayson | Carnets |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (425 ratings) | 4.6 (316 ratings) — better |
| Positive reviews | 80.7% of reviews — better | 78.4% of reviews |
| Number of ratings | 425 — better | 316 |
| Update frequency | Every 3 weeks — better | Monthly |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Best chart rank | #97 | #93 — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 26.0 | 14.0 — better |
| Further details — not scored | ||
| Size | 41 MB | 1.4 GB |
| Age rating | 4+ | 17+ |
| Developer | Simon B. Støvring | Nicolas Holzschuch |
Customer experience
Jayson
Carnets
User reviews
Jayson
From 425 App Store ratingsWhat we love
- 👍 Elegant and intuitive JSON editing interface
- 🎯 Perfect for FNF mod development and updates
- 📱 Excellent iOS implementation with native feel
- 🔧 Powerful JSON manipulation capabilities
- ⚡ Great Shortcuts and URL scheme integration
Room to improve
- 🐛 Frequent crashes and instability issues
- 🔋 High battery consumption and device heating
- ❌ Missing search functionality
- 📵 Safari browser support issues
- 🔒 Limited free features, paywall for advanced options
Carnets
From 316 App Store ratingsWhat we love
- 🚀 Excellent app for coding on iPad
- 👍 Convenient for learning and coding on the go
- 🚀 Works just like Jupyter Notebook on desktop
- 👍 Helpful for self-learning Python
- 👍 Useful for data science and machine learning
Room to improve
- 🐛 Bugs and stability issues
- 🔋 Battery drain and overheating
- 🔒 Unauthorized access to photo library
- 🐛 Issues with importing certain libraries like SciPy and Scikit-learn
Bugs and requests
Jayson
Reported bugs
6 issues- App crashes when opening large JSON files (89MB+)
- Crashes on regular use despite functionality
- Device freezing for extended periods
- Safari compatibility broken in recent updates
- Navigation back through JSON structure is unreliable
Show 1 moreShow fewer
- Accidental file exit when attempting to navigate
Requested features
9 requests- Search/find functionality within files
- JSON editing and modification capabilities
- XML format support
- Split-view for comparing different arrays
- Export functionality for edited JSON
Show 4 moreShow fewer
- Comment recognition in JSON files
- Plain text editor option
- Improved file size handling for large documents
- Better navigation controls on mobile devices
Carnets
Reported bugs
4 issues- Crashes and freezes
- Issues with saving and loading notebooks
- Problems with running scripts and notebooks
- Incompatibility with newer iOS versions
Requested features
5 requests- Add support for SciPy, Scikit-learn, and other scientific computing libraries
- Improve file management and integration with cloud storage services
- Implement split-screen or multi-window support
- Add more keyboard shortcuts and customization options
- Improve error handling and provide more detailed error messages
In-app purchases
Jayson
- Unlock Everything$4.99
Carnets
No in-app purchases









