Find JSON Changes Online

Find JSON changes by path, including added fields, removed keys, modified values, and nested object differences.

Paste your JSON → Get results instantly (no signup)

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Try examples:

→ Compare these JSON inputs and return a report of changed, added, and removed fi...

Output✓

{
  "plan": "pro",
  "features": {
    "aiDraft": true,
    "history": true,
    "apiAccess": true
  },
  "limits": {
    "documents": 100
  }
}

Output✓

1{
2  "changed": [
3    {
4      "kind": "changed",
5      "path": "plan",
6      "before": "starter",
7      "after": "pro"
8    },
9    {
10      "kind": "changed",
11      "path": "features.aiDraft",
12      "before": false,
13      "after": true
14    },
15    {
16      "kind": "changed",
17      "path": "limits.documents",
18      "before": 10,
19      "after": 100
20    }
21  ],
22  "added": [
23    {
24      "kind": "added",
25      "path": "features.apiAccess",
26      "value": true
27    }
28  ],
29  "removed": [
30    {
31      "kind": "removed",
32      "path": "features.legacyExport",
33      "value": true
34    }
35  ]
36}

Love the result?

Use this exact pipeline in your app, backend, or LLM workflow.

No setup needed. Works with curl, Node, Python.

Uses example data. For edited input, copy from the playground.

Read integration guide

Works with:

Change detection
Release QA
Modified field reports
Before-and-after JSON

Example: input → output

Inputs / Output

Output

Find JSON changes

Find JSON changes when you need to know what changed between two versions of a payload. The report should separate added fields, removed keys, modified values, and nested path changes.

This page uses the same engine as the JSON diff tool, but the content is written for change-detection intent.

How to find changes in JSON

Paste the older JSON into the baseline side and the newer JSON into the updated side. Run the comparison and review each change by path. Look for values that changed, fields that appeared, and keys that disappeared.

If the payload contains unstable metadata, remove those fields before comparing so the report focuses on meaningful changes.

JSON change detection example

If a response changes from "status": "trial" to "status": "active", the report should show a modified value. If features.apiAccess appears only in the new payload, it should show an added field. If legacyMode disappears, it should show a removed key.

Common use cases

Track API response changes.
Review version differences.
Check generated JSON revisions.
Validate migration output.
Audit config changes before release.

Why JSON change detection matters

Small JSON changes can break integrations, reports, billing logic, feature flags, and automation. A structured change report gives you a direct list of affected paths so you can decide whether each change is expected.

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Compare JSON objects - object-level field comparison.
JSON file diff - saved-file and fixture diff workflow.
Compare API JSON responses - endpoint and webhook response comparison.

JSON Validator - validate JSON before change detection.
JSON Formatter - format JSON before comparing.
Clean JSON - remove noisy values.
Flatten JSON - make nested change paths easier to scan.
Extract Fields from JSON - check only important paths.
JSON Pipeline - automate repeatable JSON change checks.

Related tools

Related comparisons

JSON Diff / Change Report

v1.0.0

Compare

objectarray

Description

JSON Diff / Change Report

Compare two JSON inputs and output a structured report or focused diff subset. Accepts a primary input (the new JSON) and secondary input (the old JSON), then shows what changed, was added, or was removed between them.

How It Works

This utility requires two inputs — primary (the "new" version) and secondary (the "old" version). It performs a deep comparison and outputs results based on the selected mode.

Diff Modes

Report

Return a structured report with changed, added, and removed arrays. Entries include dot paths, kind, and either before/after values or the added/removed value.

Changed Only

Return the subset of the new JSON that differs from the old JSON. Modified and added fields are included; removed fields are excluded because they do not exist in the new JSON.

Added Only

Show only fields that exist in the primary input but not in the secondary. Useful for detecting new additions.

Removed Only

Show only fields that exist in the secondary input but not in the primary. Useful for detecting deletions.

Full Annotated

Show all fields with _diff_ markers indicating their status: "unchanged", "changed", "added", or "removed". Provides a complete picture of all differences.

Configuration

Field	Type	Default	Description
Diff Mode	enum	`report`	`report`, `changed-only`, `added-only`, `removed-only`, or `full-annotated`

Use Cases

Version Comparison

Config changes: Compare two versions of a configuration file to see what changed
API responses: Diff API responses before and after a deployment
Schema evolution: Identify added or removed fields between schema versions

Data Validation

Migration verification: Compare source and target data after migration
Sync detection: Find out-of-sync records between two data sources
Audit trail: Track exactly which fields were modified in an update

Debugging

State inspection: Compare application state before and after an action
Response diffing: Compare expected vs. actual API responses
Regression detection: Identify unexpected changes in output data

Configuration

Name	Type	Default	Description
Diff Mode	`enum`	`report`	report: return changed, added, and removed entries with paths. changed-only: show the new JSON subset with modified and added values. added-only: show only new keys. removed-only: show only deleted keys. full-annotated: show all with _diff markers. `report` `changed-only` `added-only` `removed-only` `full-annotated`

Examples

AI Prompt

Compare these JSON inputs and return a report of changed, added, and removed fields.

Output✓

{
  "plan": "pro",
  "features": {
    "aiDraft": true,
    "history": true,
    "apiAccess": true
  },
  "limits": {
    "documents": 100
  }
}

Output✓

1{
2  "changed": [
3    {
4      "kind": "changed",
5      "path": "plan",
6      "before": "starter",
7      "after": "pro"
8    },
9    {
10      "kind": "changed",
11      "path": "features.aiDraft",
12      "before": false,
13      "after": true
14    },
15    {
16      "kind": "changed",
17      "path": "limits.documents",
18      "before": 10,
19      "after": 100
20    }
21  ],
22  "added": [
23    {
24      "kind": "added",
25      "path": "features.apiAccess",
26      "value": true
27    }
28  ],
29  "removed": [
30    {
31      "kind": "removed",
32      "path": "features.legacyExport",
33      "value": true
34    }
35  ]
36}

Config

Diff Mode

report

API Usage

POST /api/v1/utilities/compare.json-diff

Example:

curl -X POST https://your-domain.com/api/v1/utilities/compare.json-diff \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"inputs":{"primary":{"plan":"pro","features":{"aiDraft":true,"history":true,"apiAccess":true},"limits":{"documents":100}},"secondary":{"plan":"starter","features":{"aiDraft":false,"history":true,"legacyExport":true},"limits":{"documents":10}}},"config":{"mode":"report"}}'

Response

1{
2  "changed": [
3    {
4      "kind": "changed",
5      "path": "plan",
6      "before": "starter",
7      "after": "pro"
8    },
9    {
10      "kind": "changed",
11      "path": "features.aiDraft",
12      "before": false,
13      "after": true
14    },
15    {
16      "kind": "changed",
17      "path": "limits.documents",
18      "before": 10,
19      "after": 100
20    }
21  ],
22  "added": [
23    {
24      "kind": "added",
25      "path": "features.apiAccess",
26      "value": true
27    }
28  ],
29  "removed": [
30    {
31      "kind": "removed",
32      "path": "features.legacyExport",
33      "value": true
34    }
35  ]
36}

Love the result?

Example: input → output

Find JSON changes

How to find changes in JSON

JSON change detection example

Common use cases

Why JSON change detection matters

Related conversions

Related tools

Related tools

Related comparisons

Read more on the blog

JSON Diff / Change Report

Description

JSON Diff / Change Report

How It Works

Diff Modes

Report

Changed Only

Added Only

Removed Only

Full Annotated

Configuration

Use Cases

Version Comparison

Data Validation

Debugging

Configuration

Examples

API Usage

Related Tools

JSON Validator

JSON Formatter

JSON to CSV

Clean Values

Flatten / Nest