JSON Delta
Compare JSON payloads with semantic tree delta, split diffing, and RFC 6902 patch generation.
Google Cloud • AI & Developer Infrastructure
Understanding Semantic JSON Comparison & RFC 6902 JSON Patch
JSON Delta executes zero-leak, deterministic structural comparisons entirely inside your browser memory. Whether you are debugging microservices contracts, comparing Kubernetes configs, or generating Git-compatible unified diffs, no data ever leaves your device.
How It Works (In-Memory Execution)
- Lexical Syntax Parsing: Both input strings are parsed into recursive Abstract Syntax Trees (AST) in memory with validation error boundaries.
- Recursive Structural Traversal: The engine walks properties in parallel, classifying modifications by addition (+), deletion (-), or type/value changes (~).
- Longest Common Subsequence (LCS): Line-by-line diffing uses dynamic programming matrix backpropagation to align identical lines cleanly in side-by-side view.
- RFC 6902 Serialization: Differences are compiled into standard JSON Patch operations (add, remove, replace) ready for REST API PATCH endpoints.
RFC 6902 Patch Operation Cheatsheet
| Parameter / Token | Description | Example |
|---|---|---|
| add | Inserts a new value into an object or inserts an element into an array at the target index. | {"op": "add", "path": "/users/0", "value": {"name": "Alice"}} |
| remove | Removes an object member or array element at the target path location. | {"op": "remove", "path": "/database/password"} |
| replace | Replaces the existing value at the target path with a new value. | {"op": "replace", "path": "/version", "value": "2.0.0"} |
| move | Removes the value from one location and adds it to another target location. | {"op": "move", "from": "/oldName", "path": "/newName"} |
Frequently Asked Questions
Q: Is my JSON payload sent to a server?
No. DevCraft operates 100% in your browser RAM. Your network activity remains completely zero, making it safe for proprietary production tokens, credentials, and customer PII.
Q: What is RFC 6902 JSON Patch?
RFC 6902 is an IETF standard that defines a JSON document structure for expressing a sequence of operations to apply to a target JSON document, commonly used in HTTP PATCH methods.
Q: How does URL Sharing work without a database?
When you click 'Share URL', your JSON data is compressed using LZ-String algorithm into the URL hash fragment (#data=...). Browsers never send URL hashes to web servers, preserving complete air-gapped privacy.