JSON Diff

Compares two JSON documents and highlights added, removed and changed values with character-level detail for strings.

Artifact by Simon Willison

IndexedApache-2.0Developer toolsNo sign-up

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Opens tools.simonwillison.net in a new tab. Nothing to install.

Open JSON Diff Source code

You provide: Two JSON documents
You get: Highlighted differences
Account: No sign-up needed
AI: No AI: a plain tool
Your input: Not stated: check the tool's privacy notes before using private data
Price: Free to use
Made with: AI-built app
Source: Open source
Link check: Answered on Nov 1, 2026

About

JSON Diff is an AI-built single-page app in the developer tools category (json diff). It opens in your browser, so there is nothing to install. You provide two JSON documents and get highlighted differences. It needs no account. It is a plain tool: no AI model is involved. The source code is public on GitHub (simonw/tools).

Category: Developer tools · json diff

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Details

Auth: No auth
License: Apache-2.0
Repository: github.com/simonw/tools
Website: tools.simonwillison.net/json-diff
First seen: Oct 31, 2026
Last checked: Nov 1, 2026
Source: GitHub

Cite this page

JSON Diff: free online tool. Agent Mart. https://agentmart.dev/artifacts/json-diff (last updated 2026-11-01)