JavaScript Object Notation

JavaScript Object Notation
Name	JavaScript Object Notation
Extension	.json
Mime	application/json
Designer	Douglas Crockford
Introduced	2001
Fileformat	Text-based
Genre	Data interchange format

JavaScript Object Notation is a lightweight text-based data interchange format used for serializing structured data. It is commonly employed for configuration, APIs, and data exchange across platforms, and is supported by many languages and runtimes including Node.js, Python (programming language), Java (programming language), Ruby (programming language), and Go (programming language). The format emphasizes human-readable syntax and machine-parsable structure, making it widely adopted by projects such as Mozilla Foundation, Google LLC, Facebook, Inc., Twitter, Inc., and standards bodies like the Internet Engineering Task Force.

Overview

JSON is a text format derived from object literal notation in ECMAScript, with a focus on simplicity and interoperability among systems such as Apache HTTP Server, NGINX, Microsoft Azure, Amazon Web Services, and Google Cloud Platform. It is often used where formats like XML and YAML might be considered too verbose or too permissive; major applications include RESTful services used by GitHub, Stripe, Inc., PayPal, and Slack Technologies. JSON's ecosystem intersects with projects like jQuery, AngularJS, React (JavaScript library), Django (web framework), and data tools such as Elasticsearch, MongoDB, and Cassandra (database).

History

The format was popularized in the early 2000s by a proponent at Sun Microsystems and evolved through community use in environments influenced by Netscape Communications Corporation and the Mozilla Foundation. Key figures and organizations associated with its spread include Douglas Crockford, Yahoo!, Google LLC, and contributors from IETF and ECMA International, culminating in standardization efforts and documentation adopted by implementers such as Microsoft Corporation and Apple Inc.. JSON's rise paralleled the growth of web APIs used by platforms like YouTube, Flickr, PayPal, Amazon.com, and social networks including Facebook, Inc. and LinkedIn.

Syntax and Data Types

JSON encodes data using a small set of structures: objects (unordered name/value pairs) and arrays (ordered values), with primitive types including strings, numbers, booleans, and null. Implementations in engines such as V8 (JavaScript engine), SpiderMonkey, Java Virtual Machine, and CLR map these to native types in languages like C++,[ [C#, Rust (programming language), and Haskell (programming language). String encoding follows Unicode conventions, while numeric representation relates to IEEE 754 double-precision in many environments; distinctions appear in systems like PostgreSQL, MySQL, SQLite, and Oracle Database. Tooling for schema and validation often references standards and projects including JSON Schema, OpenAPI Specification, GraphQL, and libraries associated with Apache Software Foundation projects.

Serialization and Parsing

Serializers and parsers convert between in-memory representations and textual JSON; prominent parsers include engine-native functions in Node.js, Python (programming language), and Java (programming language), as well as third-party libraries like Jackson (software), Gson, RapidJSON, Newtonsoft.Json, and serde (Rust). Performance and memory usage are optimized in projects such as V8 (JavaScript engine), SpiderMonkey, GraalVM, and database connectors for MongoDB, Redis, and PostgreSQL. Interchange in web contexts relies on protocols and frameworks like HTTP/1.1, HTTP/2, WebSocket, gRPC, and platforms including AWS Lambda, Google App Engine, and Heroku.

Security and Limitations

JSON's simplicity reduces certain classes of errors, but parsing untrusted input can expose applications to risks exploited in incidents involving major vendors such as Equifax, Target Corporation, and supply-chain events tracked by National Institute of Standards and Technology. Common concerns include injection attacks when JSON is embedded in contexts handled by AngularJS, jQuery, ASP.NET, or custom parsers, type coercion issues in languages like JavaScript and PHP, and denial-of-service vectors like large or deeply nested documents that affect runtimes such as Node.js and Tomcat (software). Mitigations involve input validation, strict content-type handling with HTTP, safe parsers used by OpenBSD and FreeBSD packages, and adherence to guidelines from organizations like OWASP.

Implementations and Libraries

A broad ecosystem supports reading and writing JSON across platforms: native APIs in Node.js, Python (programming language), Ruby (programming language), PHP, Java (programming language), and .NET Framework; high-performance libraries such as RapidJSON, Jackson (software), Gson, Newtonsoft.Json, and serde (Rust); and integration in tools like cURL, Postman, jq (command-line tool), and Kubernetes. Application frameworks and services in ecosystems maintained by Red Hat, Canonical (company), IBM, Microsoft Corporation, and Google LLC incorporate JSON handling in middleware, logging, and API gateways used by enterprises including Walmart, Netflix, Airbnb, and Uber Technologies, Inc..

Category:Data serialization formats