JSON Tools

Online JSON Diff

An online deep diff with parse-error reporting.

Compare two JSON documents and highlight what changed. Example: paste an old and new API response to spot added or removed keys.
Compare two JSON
  1. Paste the original JSON.
  2. Paste the changed JSON.
  3. Review the highlighted differences.
Example: compare two JSON objects and spot what changed.
Use to diff an old and new payload.
Client-sideRuns entirely in your browser — your data never leaves your device.

Online JSON Diff is a browser-based web developer tool on WebDevToolsBase. An online deep diff with parse-error reporting. To use it, paste your input and view the result directly in your browser — no signup and nothing to install.

Online JSON Diff is a free JSON Tools utility that runs entirely in your browser — nothing you enter is uploaded.

JSON A (left)
JSON B (right)
Differences
Compares all object members safely, ignores object-key order, and compares arrays by index. Numbers are compared as exact decimal values; original number text is retained in differences. Paths use JSON Pointer escaping (~0 for ~ and ~1 for /). Duplicate object member names are rejected. Structural equality does not prove that two JSON Schemas allow the same data.


 
How to use Online JSON Diff
 
  1. Paste the original JSON into the left panel and the revised JSON into the right panel.
  2. Edit either panel to run the comparison. A selected JSON file is read locally when this page offers file controls.
  3. Read + as added in the right document, − as removed from the left document, and ~ as changed. Paths identify the affected value.
  4. Use Copy after the comparison completes. Resolve any syntax or duplicate-member error before copying another result.
 
About this tool
 
This tool compares the structure and values of two JSON documents. Object member order is ignored; array positions are compared in order. Schema documents are compared as JSON data, so an equal or different result does not establish schema validity, logical equivalence, or compatibility.
 
Comparison runs in this browser. Entered JSON and selected file content are not sent to a comparison service. Keep original files separately; this tool produces a difference report and does not merge changes into either file.
 
Frequently asked questions
 
 
What does Online JSON Diff do?
Online JSON Diff lets you compare your input right in the browser, with the result shown instantly and nothing uploaded.
 
Do I need an account for Online JSON Diff?
No — Online JSON Diff needs no account, sign-up or installation.
 
Where is my data processed by Online JSON Diff?
Entirely in your browser — Online JSON Diff keeps your data on your own machine and sends nothing anywhere.
 
Can Online JSON Diff handle large or deeply nested JSON?
Size is limited by the memory and responsiveness of your browser. Deeply nested and large files can take longer to parse and display. Save the original files and use a small representative example before comparing a large document.
 
Can I use Online JSON Diff without a connection?
Yes — after the first load Online JSON Diff runs entirely offline.
 
 
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