JSON Editor
Edit and explore JSON with a live split-panel code and tree view editor.
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Code
Tree
Edit and explore JSON with a live split-panel code and tree view editor.
This free JSON Editor from KX Toolkit is part of our all-in-one online toolkit. It runs entirely in your browser, so your data never leaves your device for client-side operations. 100% free, forever - no paywall, no credit card, no trial.
How to use the JSON Editor
- Paste your input - JSON, regex pattern, JWT, URL etc.
- Pick any flags or options the tool supports.
- Click the action button (Format, Test, Decode).
- Copy the result or download it as a file.
What you can do with the JSON Editor
- Format and validate API responses while debugging.
- Test regex patterns against real input before deploying.
- Decode JWTs to inspect claims and expiry.
- Generate UUIDs for migrations, tests and seeders.
Why use KX Toolkit's JSON Editor
- Browser-based: Works on Windows, macOS, Linux, iOS and Android - no install, no extension.
- Privacy-first: Client-side tools never upload your data; server-side tools delete files right after processing.
- Mobile-friendly: Full feature parity on phones and tablets - not a stripped-down view.
- Fast: Optimised for instant feedback. No artificial waiting screens, no email-gated downloads.
- One hub for everything: 300+ tools across SEO, text, image, PDF, code, color, calculators and more - skip switching between sites.
Tips for the best results
Bookmark the most-used tools - your browser bookmark bar is faster than retyping the URL every time.
Related Developer Tools
If you find this tool useful, explore the full Developer Tools collection or browse our complete tool directory. KX Toolkit is built for marketers, developers, designers, students and anyone who needs a quick utility without signing up for yet another SaaS.
What is the difference between code view and tree view?
Code view shows raw JSON text where you can type, paste, and use search and replace. Tree view shows a hierarchical outline where you can expand or collapse objects and arrays, rename keys, change value types, and drag to reorder. The split view keeps both in sync, so structural edits in tree mode reflect immediately in the formatted text.
Can I edit JSON without breaking its structure?
Yes. The tree view enforces valid types so you cannot accidentally produce invalid syntax such as unquoted keys or trailing commas. The code view validates on every keystroke and surfaces parse errors with line numbers. If something looks off, the tool refuses to switch views until the JSON parses, preventing silent corruption of nested data.
Does it handle deeply nested or large JSON well?
It handles documents up to several megabytes smoothly. For very deep nesting the tree view stays responsive because it virtualizes nodes that are collapsed. Extremely large arrays - say tens of thousands of items - may slow down rendering when fully expanded; collapse parent nodes or paginate the source data to keep interaction snappy.
Can I use it to compose API request bodies?
Yes. Build the request body in tree view by adding fields with the right types, then copy the formatted or minified text into your HTTP client. Because the tool validates as you type, you avoid the classic mistake of hand-crafting invalid JSON. It is a faster workflow than free-typing in a terminal, especially for nested or array-heavy payloads.
Is my data uploaded anywhere?
No. Editing happens entirely in your browser tab - there is no server roundtrip, no telemetry on content, and no third-party calls with the JSON body. Closing the tab discards the data unless you copy or download it first. This makes it safe for proprietary or sensitive payloads such as customer records and API tokens.
What is the best way to compare two JSON documents?
Format both with the same indentation and key order, then diff the formatted text in a text-diff tool. Sorting keys alphabetically before diffing eliminates noise from reordering. For semantic comparison that ignores key order entirely, use a dedicated JSON diff library or jq with the --sort-keys flag rather than a line-based text diff.
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