How do I compare two JSON objects?

Paste the first JSON on the left and the second on the right, then click Compare. The tool shows a structural diff highlighting added, removed, and changed values with their full paths.

Does JSON Compare check key order?

The tool performs a semantic comparison, meaning it compares the actual data regardless of key order. {"a":1,"b":2} and {"b":2,"a":1} are treated as equal because they represent the same data.

Can I compare API responses?

Yes, that's one of the most common uses. Paste the expected API response on one side and the actual response on the other. The diff output immediately shows any discrepancies in structure or values.

Can I compare model responses or tool-call payloads?

Yes. Paste one model response on the left and another on the right to see exactly which fields changed between prompts, model versions, or tool runs. This is especially useful when both outputs look similar but break downstream code differently.

What does the diff output mean?

Green lines with a + sign indicate values present only in the second JSON. Red lines with a - sign indicate values present only in the first JSON. Yellow/orange lines indicate values that exist in both but differ.

JSON 比較

2 つの JSON を構造的に diff

左（原文）

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右（変更後）

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See exactly what changed between two JSON payloads

Eyeballing a diff between two long JSON files is painful and error-prone. A structural compare ignores key order, normalizes whitespace, and shows you only what actually changed — added keys, removed keys, value differences — with the full path to each change so you can act on it instead of hunting for it.

Use the comparer when you need to

Diff two API responses

Confirm whether a backend change altered the response shape or values between deploys, environments, or versions.

Spot regressions in fixtures or snapshots

Find the field that drifted in a test fixture or snapshot file without manually re-reading the whole document.

Compare model outputs across runs

Diff structured AI responses to see which fields are stable and which fluctuate between prompts or model versions.

How to compare JSON quickly

1
Paste the first JSON document on the left and the second on the right.
2
Click Compare to see additions, removals, and value differences with full paths.
3
Copy or share the diff to discuss the change with a teammate.

Keep going

Validate against an expected shape

Move from ad-hoc diffs to enforcing a schema when the contract really matters.

Validate model output

Combine diff and schema checks for AI-generated JSON to catch shape and value drift in one place.

Format both inputs first

Beautify both payloads before diffing for the cleanest reading experience.

Compare non-JSON text

Use line-based diff for logs, configs, and plain text where structure isn't JSON.

Common compare workflows

Investigate an unexpected staging response

Paste prod and staging payloads side-by-side to find the exact field that drifted.

Validate an API migration

Confirm the new endpoint returns the same structure and values as the legacy one before flipping clients.

Audit a model upgrade

Compare structured output from two model versions on the same prompt to verify downstream code still works.

よくある質問

左に1つ目、右に2つ目のJSONを貼り付けて「Compare」をクリックします。追加・削除・変更された値を、フルパス付きの構造的なdiffとしてハイライト表示します。

このツールはセマンティック比較（意味的比較）を行うため、キーの順序は無視して実データを比較します。{"a":1,"b":2} と {"b":2,"a":1} は同じデータとして等価に扱われます。

はい。代表的な用途のひとつです。期待するレスポンスを片側に、実際のレスポンスをもう片側に貼り付けると、構造や値の差分がすぐに分かります。

+ の付いた緑の行は、2つ目のJSONにのみ存在する値です。- の付いた赤の行は、1つ目のJSONにのみ存在する値です。黄／オレンジは、両方に存在するものの値が異なる箇所を示します。