Developer Tools

Format, Validate and Locate JSON Errors

Free online JSON Formatter, Parser, Validator and Viewer: pretty-print, minify, validate syntax, search keys and explore a tree view. Every // comment is highlighted, and processing stays in your browser.

Input JSON

Supports objects, arrays, strings, numbers and booleans.

JSON does not support // annotations; the error location will be automatically marked after pasting.

Result

Waiting for JSON input.

The results will be displayed here.
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How to use the JSON formatter

  1. Paste JSON into the input area above.
  2. Choose Format JSON to organise its indentation and structure.
  3. Enter a key or value such as bet_id in the search box below. Every match is highlighted and the first match is brought into view.
  4. Use ↑ / ↓ to move between matches, use + / − to expand or collapse data, then copy the processed JSON when finished.
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What is JSON?

JSON (JavaScript Object Notation) is a lightweight, readable data-exchange format. It is widely used for API responses, configuration files, and data shared between front-end and back-end services.

Valid JSON uses double quotes for keys and text, with correctly matched braces, brackets, and commas.

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JSON Parser, Validator and Viewer

A JSON parser turns JSON text into structured data, while a validator helps identify invalid commas, quotes, or brackets. This tool also provides a JSON Viewer tree for browsing nested objects and arrays.

For long data, format it first with Pretty Print, then use search and collapse controls to locate fields and inspect API responses faster.

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Built for 2026 workflows

This JSON tool combines formatting, minifying, syntax validation, key-value search, highlighting, and a collapsible tree so large API responses and configuration files are easier to read, inspect, and copy.

Everything is processed locally in your browser; your data is not uploaded.

JSON DEVELOPER GUIDE

Online JSON Parser: parsing, validating, formatting and beautifying API JSON

When you search for JSON Parser, JSON Validator, JSON Formatter, or JSON Beautifier, it's usually because you don't understand the API response, configuration file, or webhook payload, or you're looking for a syntax error. This tool can complete JSON parsing, formatting, compression, tree view, search and error location on the same page.

When do you need a JSON Parser or JSON Validator?

  • Check whether the JSON returned by the REST API, GraphQL, webhook or configuration file is valid.
  • Pretty Print one-line JSON into an indented, easy-to-read format.
  • Find formatting errors such as missing commas, double quotes, parentheses, trailing commas, or JSON comments.
  • Search for fields in a large JSON Viewer, collapse nested objects, and copy the processed results.

Common JSON validation errors

The rules for valid JSON are stricter than JavaScript objects. When using JSON Validator, especially check for the following:

double quotesBoth key names and text must be enclosed in double quotes, single quotes cannot be used.
Commas and parenthesesCommas are required between each item, but there must be no trailing comma after the last item.
annotationStandard JSON does not support // or /* */ annotations; this tool will mark all // annotations directly.
data typeOnly strings, numbers, objects, arrays, true, false or null can be used, undefined cannot be used.

JSON Parser FAQ

What is JSON Parser?

JSON Parser will read JSON text and check whether it conforms to JSON syntax; upon success, it can convert the data into an easy-to-read structure for easy inspection of API responses or configuration files.

What is the difference between JSON and JavaScript objects?

JSON key names and strings must use double quotes, and cannot contain // or /* */ comments, trailing commas, functions, or undefined. JavaScript objects can use a looser syntax.

What is the difference between JSON Formatter, Beautifier and Minifier?

Formatter or Beautifier will add indentation and line breaks to make JSON easier to read; Minifier will remove unnecessary whitespace to reduce data size. Both require the raw JSON itself to be syntactically correct.

Will JSON data be uploaded to the server?

No. The parsing, validation, formatting and searching of this JSON Parser are all done locally in the browser, and the input content will not be uploaded to the ToolBoy server.

How to use

  1. Paste JSON data.
  2. Choose format, minify or validate.
  3. Copy the result.

Privacy

This tool does not upload JSON content or retain input after the page closes.

Common question

If an error appears, check the indicated line and column for commas, quotes or brackets.