What is a JSON Viewer?
A JSON viewer turns a wall of text into a tree you can expand and collapse. Objects and arrays become folders, and keys and values are color coded, so it is much easier to find what you are looking for in a large response.
When to use it
Use it to explore an API response, inspect a config file or understand the shape of data you did not write. If you only need to clean up the spacing, the JSON Formatter is the better fit. If you need to check validity, an invalid document will show an error here too.
How it works
Paste your JSON and the tool parses it with the browser's JSON parser. If it is valid, it is rendered as a nested tree where each object or array can be folded. If it is not valid, you get the parse error so you can fix it. Your data never leaves the page.
Frequently asked questions
What is the difference between a JSON viewer and a formatter?
A formatter re-indents the text. A viewer shows an interactive tree you can collapse and expand. Both are useful depending on the task.
Why does my JSON fail to load?
Common causes are trailing commas, single quotes instead of double quotes, unquoted keys and comments. JSON is stricter than JavaScript.
Can it handle large files?
It works for typical API responses. Very large files (many megabytes) may feel slow because everything is rendered in the browser.
Is my data private?
Yes. Parsing and display happen locally.