How to use the JSON Tree Viewer and Editor
- 1. Paste JSONAny valid JSON: an API response, config or data file.
- 2. Explore and editOpen branches, click a value to change it, or × to delete a key.
- 3. Get the JSONDownload or copy the edited, neatly formatted JSON.
Why a tree helps
Long JSON with deep nesting is hard to read as text: one missing bracket and you lose your place. A tree shows each object and array as a branch you can open or close, with its size shown, such as array [4] or object {2}. Values are colour-coded by type: strings in green, numbers in blue, true/false in pink and null in grey.
Editing keeps types safe. A number field only accepts a number, and a boolean only accepts true or false, so you cannot accidentally turn 6 into "6" or break the structure.
Worked example
The sample describes a Data Analytics course. Viewed as a tree it shows 11 keys and items, nested 2 levels deep: five top-level keys, four items in the modules array, and two keys inside mentor. Change duration_months from 6 to 7, delete "Python" from modules with ×, and press Get edited JSON. The download has the new value and a modules array of 3.
- Press Enter or click away to save an edit.
- An invalid value, like letters in a number field, is rejected and the old value comes back.
- To add new keys, edit the text version and view it again. The tree is for exploring and quick fixes.
Everything stays in your browser, which matters when the JSON holds customer data or API keys.
Frequently asked questions
Can I add new keys in the tree?
Not yet. Add them in the text box and press View as tree again.
How big a file can it handle?
A few megabytes works well. Very large files can be slow, because every node becomes an element on the page.
Does it keep my formatting?
The output uses a standard 2-space indent, which is the most common style.
Is the json tree viewer and editor free?
Yes, it is free. Getting your edited JSON the first time asks for your name and WhatsApp number once, and after that the json tree viewer and editor and every other Uncodemy tool open without the form.