Is JSON 3 still maintained or safe to use?

No, JSON 3 is deprecated and no longer maintained. The README explicitly advises against using it in new projects and recommends migrating to native JSON due to lack of updates and security patches.

JSON 3 vs JSON 2: which is better for old browsers?

JSON 3 is more secure with its recursive descent parser, but JSON 2 might be faster on older platforms. However, both are obsolete now that native JSON is standard, so neither is recommended for new work.

How to migrate from JSON 3 to native JSON in an existing project?

Remove the JSON 3 script or dependency, and test your application for compatibility issues, especially with date serialization, as JSON 3 fixed bugs that might still exist in some older native implementations. Update any code relying on JSON 3-specific features.

What browsers does JSON 3 actually support?

JSON 3 supports a wide range of browsers, including Internet Explorer 6+, Chrome 19+, Firefox 2+, Safari 3+, Opera 8.54+, and SeaMonkey 1.0+, as detailed in the compatibility section of the README.

Does JSON 3 fix date formatting bugs in IE?

Yes, JSON 3 corrects date serialization by producing simplified ISO 8601 strings, addressing non-compliant native Date#toJSON() implementations in environments like older Internet Explorer versions.

Can I use JSON 3 with RequireJS without conflicts?

Yes, JSON 3 is compatible with AMD/RequireJS, but it still exports to the global scope by default; use the JSON3.noConflict() method to avoid conflicts with other scripts that modify the global JSON object.

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json3

NOASSERTIONJavaScript

A JSON polyfill for older JavaScript platforms, providing spec-compliant parse and stringify functions.

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What is json3?

JSON 3 is a deprecated JavaScript library that provided a polyfill for the JSON object in older environments lacking native support. It implemented the `JSON.parse()` and `JSON.stringify()` methods according to the ECMAScript specification, ensuring consistent JSON handling across different platforms and fixing date serialization issues present in some native implementations.

Target Audience

Developers maintaining legacy web applications or JavaScript projects that need to run on older browsers or environments without native JSON support, such as Internet Explorer 6-7 or early versions of Node.js.

Value Proposition

It offered a reliable, spec-compliant alternative to native JSON with enhanced security through its recursive descent parser and corrected date serialization bugs, making it a trusted solution for cross-platform compatibility before native JSON became universally available.

Overview

A JSON polyfill. No longer maintained.

Use Cases

Best For

Adding JSON support to legacy web applications targeting Internet Explorer 6 or 7
Ensuring consistent JSON parsing and stringifying in older JavaScript engines like Rhino
Fixing date serialization bugs in environments with non-compliant native Date#toJSON implementations
Providing JSON functionality in CommonJS environments before native support was widespread
Maintaining compatibility in projects that must run on very old browsers without modern APIs
Using JSON in AMD/RequireJS module systems without conflicts

Not Ideal For

New projects targeting modern browsers or Node.js (v12+), where native JSON is fully supported
Applications requiring active maintenance, security updates, or community support
High-performance systems where parsing speed is critical, due to its slower recursive descent parser
Projects relying on ECMAScript 6+ features beyond JSON, as it only implements older specifications

Pros & Cons

Pros

Spec-Compliant Reliability

Implements JSON.parse() and JSON.stringify() strictly according to the ECMAScript specification, ensuring consistent behavior across diverse environments as highlighted in the README.

Security-Focused Parser

Uses a recursive descent parser instead of eval, enhancing security on older platforms vulnerable to injection attacks, a key feature noted in the project description.

Date Serialization Fix

Correctly serializes dates to simplified ISO 8601 strings, overriding buggy native Date#toJSON() implementations, which is explicitly addressed in the README's date serialization section.

Broad Cross-Platform Support

Works in web browsers back to IE6, CommonJS environments like Node.js 0.6.21+, and JavaScript engines such as Rhino, as documented in the compatibility list.

Cons

Deprecated and Unmaintained

The project is officially deprecated with no maintenance, meaning no bug fixes, security patches, or updates, as warned in the prominent banner at the top of the README.

Slower Performance

Admits to being slower on older platforms compared to JSON 2 due to its recursive descent parser, which can impact performance-critical applications.

Limited Modern Relevance

With native JSON now universally available in modern environments, its utility is confined to legacy systems, making it irrelevant for new development.

Integration Complexity

Requires careful handling with AMD loaders to avoid conflicts, and the noConflict() method is needed to restore global objects, adding setup overhead.

Frequently Asked Questions

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