JSON Visual Diff Online

About This Tool

Compare two JSON documents side by side with color-coded highlighting. This tool runs entirely in your browser — no data is ever sent to a server. Free to use, no account required.

How JSON Visual Diff Works

The visual diff engine compares two JSON documents semantically — understanding structure rather than text — and presents differences in a color-coded side-by-side layout.

Added and Removed Keys

Keys present in the right document but not the left are highlighted in green (added). Keys present in the left but not the right are highlighted in red (removed). This makes additions and deletions immediately obvious.

Changed Values

When a key exists in both documents but has a different value, both sides are highlighted in yellow. The exact values are shown side by side for direct comparison.

When to Use JSON Visual Diff

Visual diff is valuable whenever you need to understand what changed between two versions of a JSON document.

Comparing API Versions

When a third-party API releases a new version, compare sample responses to spot breaking changes — removed fields, renamed keys, or changed value types — before updating your integration.

Reviewing Configuration Changes

Before deploying updated configuration files, diff the current production config against the new one to confirm exactly what will change and catch unintended modifications.

Visual JSON Diff: Color-Coded Comparison

A visual JSON diff makes it immediately clear what changed between two documents. Color coding replaces tedious manual inspection — green for additions, red for removals, yellow for modifications.

Visual Diff Color Legend

Example Diff Scenario

// Original API Response (v1)
{
  "version": 1,
  "user": {
    "name": "Alice",
    "plan": "free",
    "credits": 100
  },
  "deprecated": true
}

// Modified API Response (v2)
{
  "version": 2,              // CHANGED (yellow)
  "user": {
    "name": "Alice",         // unchanged
    "plan": "premium",       // CHANGED (yellow)
    "credits": 100,          // unchanged
    "trialEnds": "2025-01-01" // ADDED (green)
  }
  // "deprecated" REMOVED (red)
}

JSON Diff in CI/CD Pipelines

# Compare JSON files in shell
jq --sort-keys . file1.json > /tmp/a.json
jq --sort-keys . file2.json > /tmp/b.json
diff /tmp/a.json /tmp/b.json

# Node.js: deep comparison
const deepEqual = require("fast-deep-equal");
if (!deepEqual(oldConfig, newConfig)) {
  console.log("Config changed!");
}

# Python
import json, deepdiff
diff = deepdiff.DeepDiff(old_data, new_data)
print(diff)

Understanding the JSON Visual Diff Output

The visual diff compares two JSON documents semantically — key order and whitespace are ignored. Each change type is highlighted with a distinct colour so you can instantly identify what was added, removed, or modified between versions.

Colour Key

• Green (added): Key or value exists in the right document but not the left.
• Red (removed): Key or value exists in the left document but not the right.
• Yellow / orange (modified): Key exists in both documents but the value changed.
• Unchanged: Shown in normal text for context.

// Left (original)               // Right (updated)
{                                 {
  "name": "Alice",                  "name": "Alice",
  "age": 30,          →  modified   "age": 31,
  "status": "pending", →  modified   "status": "active",
  "temp": true         →  removed
                       →  added      "role": "admin"
}                                 }

JSON Visual Diff vs Text Diff

Text-based diff tools such as git diff compare files line by line. This works well for source code but produces noisy, hard-to-read output for JSON, where a single structural change may reformat dozens of lines. A semantic JSON diff ignores formatting entirely and only reports actual data changes.