JSON Patch RFC 6902 Online

About This Tool

Apply JSON Patch operations: add, remove, replace, move, copy, test. This tool runs entirely in your browser — no data is ever sent to a server. Free to use, no account required.

What JSON Patch Is (RFC 6902)

JSON Patch is a standard for expressing incremental changes to a JSON document using a sequence of typed operations.

JSON Patch Operations

Six operations cover all possible changes: add inserts new values, remove deletes them, replace updates existing values, move relocates values, copy duplicates values, and test asserts a value equals an expected value before the patch proceeds.

Applying Patches

A patch document is a JSON array of operation objects. Each object has an "op" field (the operation name), a "path" field (a JSON Pointer to the target location), and optionally "value" (the new value) and "from" (source path for move/copy).

JSON Patch vs JSON Merge Patch

Two different RFC standards address partial JSON updates — each has distinct strengths.

When to Use JSON Patch

Use JSON Patch when you need precise control: updating a specific array element by index, moving values between paths, or using the test operation as a precondition check before making changes.

When to Use JSON Merge Patch

JSON Merge Patch (RFC 7396) is simpler: send just the fields you want to change, and null means delete. It is easier to read and write for simple updates, but cannot express all changes that JSON Patch can.

JSON Patch (RFC 6902) Reference

JSON Patch defines a way to describe changes to a JSON document using a sequence of operations. It's used in REST APIs (HTTP PATCH), version control, and document collaboration.

All 6 Patch Operations

// Original Document
{"name": "Alice", "age": 30, "roles": ["user"]}

// Patch Document (array of operations)
[
  {"op": "replace", "path": "/name",      "value": "Bob"},
  {"op": "add",     "path": "/email",     "value": "bob@example.com"},
  {"op": "remove",  "path": "/age"},
  {"op": "add",     "path": "/roles/-",   "value": "admin"},
  {"op": "copy",    "path": "/backup",    "from": "/name"},
  {"op": "move",    "path": "/fullName",  "from": "/name"},
  {"op": "test",    "path": "/fullName",  "value": "Bob"}
]

// Result
{"fullName": "Bob", "email": "bob@example.com", "roles": ["user","admin"], "backup": "Bob"}

JSON Patch Operations Reference

JSON Patch in JavaScript

// npm install fast-json-patch
import jsonpatch from "fast-json-patch";

const original = {name: "Alice", age: 30};
const patch = [
  {op: "replace", path: "/name", value: "Bob"},
  {op: "add", path: "/email", value: "bob@example.com"}
];

const result = jsonpatch.applyPatch(original, patch).newDocument;
console.log(result); // {name:"Bob", age:30, email:"bob@example.com"}

JSON Patch Operations Reference

RFC 6902 defines six operations. Each operation is a JSON object in the patch array with an op field specifying the action. All operations are applied atomically — if any fails, none are applied.

// Original document
{"name": "Alice", "age": 30, "status": "pending", "temp": true}

// JSON Patch
[
  {"op": "replace", "path": "/age",    "value": 31},
  {"op": "replace", "path": "/status", "value": "active"},
  {"op": "remove",  "path": "/temp"},
  {"op": "add",     "path": "/role",   "value": "admin"},
  {"op": "test",    "path": "/name",   "value": "Alice"}
]

// Result
{"name": "Alice", "age": 31, "status": "active", "role": "admin"}

JSON Patch vs JSON Merge Patch

RFC 6902 (JSON Patch) and RFC 7396 (JSON Merge Patch) are both standards for updating JSON documents, but they have very different formats and capabilities.