JSON to Objective-C Converter

JSON (JavaScript Object Notation) is used for REST API responses, configuration files, NoSQL documents. Writing Objective-C models from JSON by hand is repetitive and error-prone. This converter automates that step entirely — paste your JSON, get Objective-C models instantly.

How to use this converter

1. Paste your JSON into the left editor panel
2. Click Generate
3. Copy the generated Objective-C code from the right panel

No account. No upload. No tracking. Runs entirely in your browser.

Why automate JSON-to-Objective-C conversion?

Writing Objective-C @interface / @property definitions by hand from JSON is:

• Tedious — especially for deeply nested or large JSON payloads
• Inconsistent — naming conventions drift when done manually across a team
• Fragile — when the JSON schema changes, hand-written models lag behind

Objective-C uses NSCoding or NSJSONSerialization for serialization — this converter generates @interface headers with appropriate property types.

This converter handles all of that automatically, giving you idiomatic Objective-C code that matches your JSON structure exactly.

Objective-C and JSON: what you need to know

Objective-C is a object-oriented, Smalltalk-influenced language, legacy iOS/macOS development and maintained Cocoa codebases. It uses NSObject subclass with property declarations for structured data — making it a natural fit for JSON-driven applications.

What the converter generates

The output consists of Objective-C @interface headers with @property declarations. This is the idiomatic pattern for Objective-C data models, compatible with popular Objective-C serialization libraries.

A common gotcha

Objective-C has no generics — collections like NSArray and NSDictionary are untyped unless annotated with lightweight generics (NSArray<NSString *>).

JSON input characteristics

JSON supports nested objects, arrays, strings, numbers, booleans, and null. Tools like jq, Postman, and browser DevTools make JSON the most developer-friendly data exchange format.

Common use cases

• Onboarding new team members by auto-generating the data layer
• Validating JSON contract compatibility with Objective-C type definitions
• Generating Objective-C models from legacy iOS apps API responses
• Creating typed DTOs for macOS Cocoa
• Rapid prototyping with real JSON payloads
• Keeping Objective-C structs in sync when JSON schemas evolve

Frequently asked questions

How are optional fields handled in the Objective-C output?

Fields that may be absent or null in your JSON are marked as optional in the generated Objective-C code. Note: Objective-C has no generics — collections like NSArray and NSDictionary are untyped unless annotated with lightweight generics (NSArray<NSString *>).

Can I use the output directly in a legacy iOS apps project?

Yes. The generated Objective-C code follows idiomatic patterns for legacy iOS apps — you can copy it directly into your project.

Does this work for large JSON payloads?

Yes. The converter is optimized for large and deeply nested JSON structures, running entirely in the browser without page reloads or server round-trips.

Does this converter support JavaScript Object Notation namespaces and nested structures?

Yes. JSON is natively parsed by all major runtimes — no schema required to begin parsing. The parser handles deeply nested structures and generates matching nested Objective-C @interface / @property definitions.

Related tools on LangStop

• JSON Formatter & Validator — https://langstop.com/json-formatter
• JSON to TypeScript Converter — https://langstop.com/json-to-typescript
• JSON to Python Converter — https://langstop.com/json-to-python
• JSON to Go Converter — https://langstop.com/json-to-go
• JSON to JSON Schema — https://langstop.com/json-to-json-schema

If you work frequently with JSON and Objective-C, bookmark this page to skip the manual model-writing step entirely.