{} JSON Diff Viewer

Compare two JSON documents and see added, removed, and changed keys highlighted. Supports deep nested structures. Free online JSON diff tool — runs in browser, no uploads.

JSON A (Original)

JSON B (Modified)

How to Use

Paste two JSON objects

Enter your original JSON in the left panel and the modified JSON in the right panel.

Click Compare

Press the Compare button to run the diff. The tool parses and validates both inputs first.

Read the color-coded diff

Green = added, Red = removed, Yellow = changed value, Grey = unchanged. Expand nested objects with the arrows.

Frequently Asked Questions

How does JSON diff work? +

The tool parses both JSON inputs and recursively compares their keys and values. Added keys (only in the right JSON) are highlighted green. Removed keys (only in the left) are red. Changed values (same key, different value) are yellow. Unchanged keys are shown in grey.

Does it handle nested objects and arrays? +

Yes — the diff is fully recursive. Nested objects are compared key by key, and arrays are compared element by element by index. Structural differences at any depth are highlighted.

What happens if one JSON is invalid? +

If either input is not valid JSON, the tool shows a parse error with the location of the problem before attempting any comparison.

Can I use this to compare API responses? +

Yes — paste two API responses (from different environments, versions, or time points) and immediately see what changed. This is a common use case for debugging regression changes in API contracts.

Is my data sent to a server? +

No. All parsing and comparison runs entirely in your browser using JavaScript. Your JSON data never leaves your device.

Guide : Comparateur JSON (JSON Diff)

Qu'est-ce que c'est ?

Le Comparateur JSON analyse deux structures JSON et affiche les différences au niveau des propriétés : valeurs modifiées, clés ajoutées ou supprimées, avec coloration visuelle.

Contrairement à un diff texte ordinaire, il comprend la structure JSON et ignore les différences de formatage insignifiantes.

Comment utiliser

Collez le premier JSON dans le panneau gauche.
Collez le second JSON dans le panneau droit.
Les différences sont surlignées par propriété.
Utilisez la vue arborescente pour naviguer dans les objets imbriqués.

Conseils professionnels

Parfait pour comparer les réponses API entre les environnements dev et prod.
Utile pour valider les migrations de données — comparez avant/après.