Complete JSON online tools guide

The JSON (acronym of JavaScript Object Notation) is an open standard format for storing and transmitting data objects in the form of human-readable text. The JSON idea is based on simple and universal ‘name-value pairs’ concept, but JSON also provides the full supports of hierarchical structures and so is suitable for almost any type of data with any level of complicity.

Being first officially released in 2002, JSON quickly became very popular among the Web developers and today it is a de-facto standard for AJAX. The key advantages of JSON are its simplicity and lightweight. Originally JSON was derived from JavaScript and therefore it’s very easy to integrate JSON with the c-based languages like JavaScript, Java, PHP, C++, C#, etc. However, as a result of its high popularity, it was developed a lot of JSON tools and libraries and today JSON is natively supported by almost any recent language and browser.

The following list will help you to find how to deal with JSON in some common programming languages:

A JSON Tutorial. Getting started with JSON using JavaScript and jQuery
PHP: JSON Manual
Working with JSON in C#
Json - Python for Beginners
JSON with Ruby and Rails

JSON fundamentals

JSON syntax

The main beauty of JSON is its simplicity and transparency. Like in JavaScript, every object in JSON must be enclosed in curly braces. The object contains name-value pairs separated by commas. Every pair consists of its name enclosed in double quotes, followed by a column, followed by a value. The below example is a simple JSON object:

The value in JSON can be one of the six types.

An integer or floating point number:

A string (must be in double quotes):

A Boolean (true or false):

Null:

An object (must be in curly braces):

An array (must be in square brackets):

Therefore, JSON object can contain an unbound set of objects and arrays of objects, containing other objects and arrays and so on.

Typical JSON problems and tasks

Despite its simplicity, in some circumstances JSON may become an origin of numerous errors. Preparing a JSON object or a part of it “manually”, i.e. not using a standard JSON serializer, a programmer has to be extremely accurate. If a server code, for example, sends a malformed JSON object to its client, JavaScript at the client side won’t be able to evaluate this object. Of course, debugger will confirm the problem, but it cannot recognize what is a problem and where is it. Now imagine that you need to find “by eye” a missed column somewhere even in a relative small JSON object like this one:

Do you feel how tedious it can be to find and fix JSON errors, and how nice it could be if you’d have a good tool helping with this task? Let’s just imagine that such a tool exists (in fact, it is):

Another origin of typical JSON errors is an issue of the special symbols. For example, fairly often we need to transfer through JSON the pieces of texts, containing double quotes. If we forget to escape this symbol in all places then our JSON object will be corrupted since double quotes has a special meaning in JSON format. Of course, a good JSON Validator can solve this problem as well.

Besides validation there are a number of other common JSON tasks requiring proper tools for. While using web services from the different vendors, in many cases it’s not enough just to read a manual. To really understand how the data is organized it’s necessary to ‘hack’ the received JSON objects, and then we need to parse and view it in the form of tree. Sometimes JSON objects should be converted to and from other formats like XML or CSV, written to and read from files, etc.

7 best online JSON formatters, validators, parsers and viewers

The following list contains seven best free online JSON tools for JSON research, development and debug purposes I found and tested. The checklist of provided features, short description and score should help you to appreciate its overall quality and compliance with your requirements in place. Of course, to get the complete picture you should visit and try these tools by yourself.

JSON Parser Online

Formatter:  Yes Validator:  Yes Error Finder:  Yes Tree View:  Yes Colorized:  Yes Collapse / Expand:  Yes Additional:  Minifier

'JSON Parser Online' is a really multifunctional tool suitable for a wide set of JSON tasks. It provides both the Strict JSON parser and JavaScript eval functions’ support. The outputs result is nicely shown in the form of well-formed colorized tree with full collapse / expand support. In addition, it also shows the JS Types of values as well as the indexes in arrays. The tool not only validates the supplied JSON object but also marks the errors in it, if any. In addition, 'JSON Parser Online' provides a minification feature and a useful set of JSON examples.

JSON Visualization

Formatter:  Yes Validator:  Yes Error Finder:  Yes Tree View:  Yes Colorized:  Yes Collapse / Expand:  Partially Additional:  Encoder / Decoder

'JSON Visualizer' is another example of very good full-featured JSON tool. Like a previous one, it provides the Strict JSON and JavaScript eval parsers. You can choose between two output views: the HTML view and the JSON tree view. Both views are well-formed and colorized, but the collapse / expand feature is missed in the JSON tree view. The tool supplies a smart validator explaining the found errors in the well-explained and easy understandable form. In addition, 'JSON Visualizer' provides a set of useful encoding / decoding features.

JSON Editor Online

Formatter:  Yes Validator:  Yes Error Finder:  Yes Tree View:  Yes Colorized:  Yes Collapse / Expand:  Yes Additional:  Visual editing, Search

'JSON Editor Online' is cool and full of features. The object parser works fine, the validator and errors finder are smart enough. The tree view is convenient, provides an excellent support for collapse / expands. A search box placed aside the tree and allowing the easy find of texts inside the filed names and values can be really helpful for a large JSON objects research. In addition, 'JSON Editor Online' has a rich set of in-place editing functions like inserting / removing the fields of different value type, changing the value types, sorting of arrays, and more. However, the interface of these features is a little bit confusing, so the use of them may be not very easy.

JSON Formatter and Validator

Formatter:  Yes Validator:  Yes Error Finder:  Yes Tree View:  Yes Colorized:  Yes Collapse / Expand:  Yes Additional:  None

Undoubtedly, 'JSON Formatter and Validator' is a pretty good online JSON tools too. The JSON objects parsing and validation are provided; the errors explanations are useful and clear. Even not colorized, the tree view is good and supports for expand / collapse. This tool provides no additional features, but it is handy for the most common operations.

jSONLint

Formatter:  Yes Validator:  Yes Error Finder:  Yes Tree View:  Yes Colorized:  No Collapse / Expand:  No Additional:  None

'jSONLint' is well-known and tried-and-true tool. Not providing additional features, it perfectly deals with the JSON objects parsing and validation. Just copy and paste the JSON object into the editing box and you will see it in the form of a simple tabulated tree. If the object contains an error, it will be found, marked and explained below.

Online JSON Viewer

Formatter:  Yes Validator:  Yes Error Finder:  No Tree View:  Yes Colorized:  No Collapse / Expand:  Yes Additional:  None

'Online JSON Viewer' is simple. It allows you switching between the plain text view you can copy a JSON object to, and the tree view with collapse / expand support. The right-side pan of the tree view provides some additional data on the selected field. However, this tool has no error finder, i.e. if your JSON is malformed, the only information you receive is a simple fact that it’s not OK.

Collapsible JSON Formatter

Formatter:  Yes Validator:  Yes Error Finder:  No Tree View:  Yes Colorized:  Yes Collapse / Expand:  Yes Additional:  None

The last tool in the list named 'Collapsible JSON Formatter' provides a not bad tree view for the JSON object. The view is colorized and provides some enhanced collapse / expand features, for example, a possibility to collapse a certain ‘level’ of the tree or change a size of tabulation. Unfortunately, 'Collapsible JSON Formatter' makes an only simple validation and doesn’t help you to find and fix errors in your JSON object.