Janice: View Large JSON Files Easily, Free App for Windows, Linux & macOS
Table of Content
Let’s be real, if you’ve ever stared at a 50,000-line JSON file in a plain text editor, you know the struggle. Endless brackets, deeply nested objects, no clear way to tell where one section ends and another begins. You’re scrolling, squinting, trying to spot a single key-value pair that might be causing a bug, and suddenly, it’s 20 minutes later, and you’re no closer to solving anything.
That’s exactly why we built Janice.
What is Janice?
It’s not just another JSON viewer. It’s a tool made by developers, for developers, and anyone else who spends too much time wrestling with messy, unstructured data. Janice is a free, fast, and lightweight desktop app that runs smoothly on Windows, Linux, and macOS, so no matter what machine you’re on, you’ve got a reliable companion.
Forget struggling through raw text. With Janice, your JSON files come alive. You can explore them like a well-organized folder: expand and collapse sections with a click, jump straight to any field, and instantly see how data fits together, all without writing a single line of code.
Whether you're:
- Debugging an API response that’s returning unexpected data
- Checking a configuration file before deploying to production
- Tracing a failed event log from a microservice
- Reviewing a JSON Dataset file (May be 2-4GB File)
- Or just trying to make sense of a giant dataset dumped from a database
This amazing app, Janice cuts through the clutter. It loads quickly, handles files up to several megabytes without lag, and keeps everything clean and readable.
We’ve tested dozens of tools over the years, some slow, some bloated, many that crash on large files or don’t even support basic features like search or syntax highlighting. Janice was built to fix those pain points.
No ads. No subscriptions. No hidden fees. Just a simple, honest tool that does one thing really well: help you understand your JSON, fast.
So if you’re tired of guessing what’s inside your JSON file, if you’re ready to stop losing time scrolling through code you can’t read, give Janice a try.
Features
- Browse through a JSON document in classic tree structure
- JSON files can be opened via file dialog, from clipboard, dropped on the window or given as command line argument
- Supports viewing very large JSON files (>100MB, >10M elements)
- Search for keys and values in the document. Supports wildcards.
- Export parts of a JSON file into a new file or to clipboard
- Copy values to clipboard
- Single executable file, no installation required
- Desktop app that runs on Windows, Linux and macOS
- Automatic dark and light theme
Platforms
- Linux: build from source, AppImage
- Windows
- macOS
FAQS
What is the largest JSON file that I can load?
The largest JSON file you can load on your computer depends mainly on how much RAM you have and on the particular JSON file. The main driver for memory consumption is the number of elements in a JSON document.
For comparison we did a load test on one of our developer notebooks. It has 8 GB RAM and runs Ubuntu 22.04 LTS. We were able to load a JSON files successfully with up to 45 million elements. The size of our test file was about 2.5 GB.
Are JSON files formatted?
Yes. The JSON document is rendered as tree and keys are shown in alphabetical order.
License
Janice is an open-source project that is released under the MIT License.
Resources & Downloads
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