Validation
Syntax issues and practical warnings
Add JSON to run validation.
JSON WORKSPACE / FORMAT · VALIDATE · EXPLORE
Make JSON make sense.
A cleaner workspace for messy payloads, nested data and oversized JSON files. Format, validate and find exactly what you need — right in your browser.
Local-first processing
Adaptive for large files
Free to use
THE STUDIO
Your JSON workbench
Browser engine ready
Untitled JSONPaste JSON or open a local file
Waiting for JSON
01
SOURCEInput
Editable · live syntax tintTip: use Ctrl/⌘ + A to select everything.0 B
02
Formatted output
Updates as you type{ }Your formatted JSON will appear herePaste, type or open a file to start.Waiting for valid JSON—
•Your data is processed locally in this browser.
Your JSON is parsed in a Web Worker. File contents are not uploaded to a processing server.
UNDER THE SURFACE
Know what’s inside
Useful context without making you dig through the payload.
Updates after each analysis
Structure
A quick profile of this payload
File size—
Lines—
Root type—
Keys—
Max depth—
Objects—
Arrays—
Null values—
Statistics appear when JSON is analyzed.
FIND THE NEEDLE
Interrogate your JSON
Jump to a nested value or search keys and values without manually scanning the whole file.
01
Path explorer
Get a value from a known path.
Try
$.config.theme or users[0].name.02
Search keys & values
Find matching names, text, IDs or values.
Search results will appear here.
A SIMPLE WORKFLOW
Less fiddling, more clarity
Format or minify
Turn a compact response into readable JSON, or strip formatting whitespace for a smaller payload.
Validate with context
See syntax errors, likely causes and line/column hints. Structural checks highlight deep nesting and duplicate object keys where detectable.
Inspect and export
Query a nested path, search for key/value matches, copy the result or download a clean JSON file.
MADE FOR REAL WORK
From API payloads to config files
A focused JSON utility for the small but important tasks that come up when building, testing and maintaining software.
01API response debugging
Paste a response copied from an API client, terminal or browser network panel. Format nested objects and arrays, then inspect a path such as $.data.items[0] to reach a field without scanning the entire response.
02Configuration review
Review files such as package.json, tsconfig.json, application settings and structured policy documents. Validation catches malformed syntax before a configuration is used.
03Data pipeline checks
Check the shape of an exported or generated payload. Object, array, key, value, null and nesting statistics help you understand what a pipeline stage produced.
04Large JSON inspection
Open a local JSON file or drop it into the editor. Parsing and traversal run in a Web Worker, while expensive live formatting and syntax decoration are reduced for larger inputs.
JSON, MADE READABLE
A JSON formatter, validator and minifier in one workspace
JSON (JavaScript Object Notation) is a text format for representing structured data. Its compact syntax is easy for applications to exchange, but API responses and configuration files can be difficult to read when objects are deeply nested or everything is written on one line.
What does a JSON formatter do?
A JSON formatter, also called a JSON beautifier, takes valid JSON and adds consistent indentation and line breaks. Objects become easier to scan, arrays are separated into readable entries, and nested values show their relationship through indentation. Formatting changes whitespace for readability; it does not add missing quotes, commas or values to invalid input.
Use Format when you need to inspect a response, compare a configuration or understand a large nested object. Choose the indentation level that fits your codebase, then copy the result or download it as a .json file.
When should you minify JSON?
A JSON minifier removes unnecessary whitespace outside strings and produces a compact representation. Minified JSON is useful when you need a smaller text payload for storage, fixtures, compact API examples or transport between systems that do not need human-readable spacing.
Minification is not the same as data compression: it removes formatting characters but does not apply a compression algorithm. Keep a formatted copy when people need to review or edit the data.
VALIDATE BEFORE YOU USE IT
Syntax errors and structural warnings are different
JSONify checks whether the input can be parsed as JSON and reports syntax problems with a helpful message and location when the browser provides one. After a successful parse, it also reviews the structure for repeated object keys, deep nesting and unusually high null density. These structural notes are warnings for inspection, not proof that the data is invalid for your application.
QUICK SYNTAX REFERENCE
Common JSON errors and how to fix them
JSON is stricter than JavaScript object-literal syntax. A small punctuation difference can make an otherwise familiar payload invalid.
| Common mistake | Invalid example | Valid JSON |
|---|---|---|
| Single quotes | {'name': 'Mira'} | {"name": "Mira"} |
| Trailing comma | {"active": true,} | {"active": true} |
| Unquoted property name | {name: "Mira"} | {"name": "Mira"} |
| Missing comma | {"id": 7 "active": true} | {"id": 7, "active": true} |
| Comments | {"mode": "safe" // note} | {"mode": "safe"} |
| Unsupported value | {"result": undefined} | {"result": null} |
JSON strings and property names use double quotes. Standard JSON does not allow comments, trailing commas, undefined, functions or unquoted property names. JSONify validates standard JSON rather than silently converting JSON-like JavaScript into JSON.
BUILT FOR REAL-WORLD PAYLOADS
Working with large JSON files in your browser
Large API responses, log exports and data snapshots can contain thousands of records and many levels of nesting. JSONify is designed to inspect these payloads without generating every visual effect for every character as soon as a file is opened.
Parsing, structural analysis, path inspection and key/value search run in a separate browser thread. For inputs above the live-preview threshold, automatic pretty-printing pauses and you can request formatted output with the Format button. Syntax colouring is also disabled for very long source text so the editor does not have to create a large number of extra HTML elements.
There is no fixed file-size promise: practical capacity depends on the browser, available device memory, the shape of the JSON and the amount of output you ask the browser to create. For very large datasets, working with a focused export or a smaller API page can still be the more efficient approach.
01
Open or drop a file
Load a local .json file or paste a payload directly into the editor.
02
Validate and profile
Review syntax feedback, file size, line count, key count, arrays, objects and nesting depth.
03
Format only when needed
Generate the readable output on demand, then copy it or download a new JSON file.
GOOD TO KNOW
Frequently asked questions
Is my JSON uploaded anywhere?
No. JSONify sends the content to a browser Web Worker for parsing and analysis. It does not upload your JSON to a processing server. The page itself still loads from its host like any website.
How large a JSON file can I open?
There is no arbitrary application-level file-size limit. The practical maximum depends on available memory, the browser, the device and how deeply nested the data is. For very large payloads, JSONify validates and analyses first, then waits for a Format click before creating a second, potentially much larger, pretty-printed string. Browser memory remains the practical limit.
Why does syntax colouring switch off for a large file?
Colouring a large document creates extra markup that can use a lot of memory. Large inputs remain editable and processable; only the decorative syntax-colour layer is disabled to keep the page more responsive.
What does the path explorer accept?
Use dot notation such as config.theme, array indexes such as users[0].email, or quoted bracket keys such as $["key.with.dots"]. Prefixing a path with $ is optional.
Can JSONify find duplicate keys?
JSONify scans the source text for repeated keys within the same object before reporting them. This matters because ordinary JSON parsing normally keeps only the last value when an object contains a repeated key.
What is the difference between Format and Minify?
Format adds indentation and line breaks for readability. Minify removes unnecessary whitespace outside strings to produce compact, valid JSON. Both preserve the parsed data values, although formatting and number notation may be normalized rather than retaining the original characters byte for byte.
Can I format a JSON array as well as an object?
Yes. JSONify accepts JSON objects, arrays and valid primitive root values such as strings, numbers, booleans and null. Arrays are formatted with the same indentation rules as nested arrays inside an object.
Does JSONify accept JSONC or JavaScript objects?
No. JSONify validates standard JSON syntax. JSONC comments, trailing commas, single-quoted strings, unquoted property names and JavaScript values such as undefined must be removed or converted before the text is valid JSON.
How can I find a value inside a nested JSON response?
Use Path Explorer for a known location, for example $.orders[0].customer.email. Use Search keys & values when you know only part of a property name, text value or ID. Search is case-insensitive and displays a limited result list with the total number of matches.
Can I use JSONify to inspect API responses and configuration files?
Yes. Paste a response from an API client, terminal or browser developer tools, or open a local configuration file such as package.json or tsconfig.json. JSONify can format it, check syntax, summarize its structure and help locate nested fields.
Does formatting change the meaning of my JSON?
Formatting and minifying preserve the parsed JSON structure and values; they change whitespace and may normalize how numbers are written. They are not a byte-for-byte preservation tool. Keep the original file when its exact text representation, ordering or numeric notation is important to your workflow.