Compare JSON Files Online

Compare two JSON files or pasted file contents locally in your browser, then review a readable field-level diff.

Paste your JSON → Get results instantly (no signup)

⚡ Instant resultsNo signupRuns in your browser

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:

Local JSON files
Export snapshots
Config files
Fixture comparisons

Example: input → output

Inputs / Output

Output

Compare JSON files online

Compare JSON files online when you need to review two saved payloads, exported configs, fixtures, snapshots, or API examples without writing a script. Paste the contents of each file into the tool, run the comparison, and review a structured report of what changed.

This file-focused workflow is useful because JSON files often contain large nested objects. A raw line comparison can be noisy after formatting, minification, or key sorting. A structured file comparison parses the contents first and then reports differences by object path.

If you want the canonical tool page, use the JSON diff comparison tool.

File comparison workflow

Start with the older file, expected fixture, or production export on one side. Put the newer file, actual fixture, or staging export on the other. Run the diff, then check whether the changed paths match what you expected.

For example, a config file review might show that features.billing was added, limits.projects changed from 5 to 20, and deprecatedMode was removed. That is more actionable than a long visual block showing braces, indentation, and surrounding unchanged fields.

Best practices before comparing files

Validate both files first if they were hand edited. JSON copied from comments, logs, or documentation can contain trailing commas, unquoted keys, or single quotes that are not valid JSON. The JSON Validator catches those errors before comparison.

Clean both files if one was minified and the other was pretty-printed, or if one export includes empty fields that the other omits. Use Clean JSON for cleanup and Normalize JSON when the same concept appears under different key names.

Flattening can also help with very deep files. Flatten JSON converts nested structures into readable paths, which makes large config comparisons easier to scan.

Common file comparison cases

Use this page for environment config review, package export checks, API fixture drift, backup comparison, release QA, generated sample review, and migration verification. It is also helpful when a teammate sends two JSON files and asks what changed but the change is buried several levels deep.

The comparison runs in the browser. That makes it convenient for local files, sensitive fixtures, and one-off reviews where installing a package would slow you down.

JSON Diff Tool - canonical structured diff workflow for added, removed, and changed fields.
JSON compare tool online - compare objects, arrays, files, and API payloads by path.
JSON difference checker - changed-field reporting for debugging payload drift.
JSON diff online - browser-based no-upload JSON comparison.
API JSON diff - compare endpoint, webhook, and SDK response changes.
Compare JSON objects - object-level field comparison.
JSON file diff - saved-file and fixture diff workflow.
Find JSON changes - added, removed, and modified field detection.
Compare API JSON responses - endpoint and webhook response comparison.

JSON Validator - check file contents before running a comparison.
JSON Formatter - clean and format pasted file contents before diffing.
Clean JSON - standardize pasted file contents before diffing.
Flatten JSON - turn nested file structures into readable paths.
Normalize JSON - reduce field-name drift between exports.
JSON to CSV - move selected file data into spreadsheet review.

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

Compare JSON files online

File comparison workflow

Best practices before comparing files

Common file comparison cases

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