JSON viewer, formatter and editor. Pretty print API responses, explore trees and graphs, search, compare and export locally.
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14
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unchanged in 30 days
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#173K
#145K among extensions
Version
0.4.10
updated 5 Oct 2026
About GOSU JSON - Viewer & Formatter
Make JSON beautiful. Find what matters faster.
GOSU JSON is an open-source JSON viewer, formatter and editor for API responses, local files and pasted text. Automatically pretty print JSON with readable indentation and syntax highlighting, then explore it in Tree, Code, Table, Graph or Diff.
Open a JSON response in Chrome to view it automatically in GOSU JSON. You can also paste JSON, drag and drop a file, or load an endpoint URL directly.
READ AND EXPLORE
• Recognize keys and values quickly with clear syntax colors.
• Expand and collapse objects and arrays in Tree.
• Read formatted JSON in Code.
• Browse arrays in a paginated Table.
• Explore nested structures visually in Graph, with expandable branches, pan and zoom.
• Expand the inspector or use fullscreen when you need more space.
• Choose a light, dark or system theme.
FIND AND EDIT
• Search keys and values using text or regular expressions.
• Click a search result to reveal and highlight its location.
• Select and copy text directly from either panel.
• Select a node to highlight its complete JSON in the source editor.
• Copy values, JSON Pointer paths or JSONPath expressions.
• Edit your local document, undo or redo changes, and download the result.
• Open JSON embedded inside a string as a separate document.
COMPARE AND EXPORT
• Compare two JSON documents in Diff.
• Download your edited JSON.
• Export all table rows as CSV or Excel-compatible XML, including rows on other pages.
• Preserve large numbers, exact decimal spellings, duplicate keys and property order when formatting.
CLEAR DOCUMENT NAVIGATION
• See which endpoint, file or pasted document you are viewing.
• New documents start in Tree with the previous search and selection cleared.
• Opening a local file clears the previous endpoint URL and refresh controls.
• Refreshing the same endpoint preserves an applicable view and returns to Tree if its selected node no longer exists.
LOCAL PROCESSING AND OPEN SOURCE
JSON parsing, formatting, searching, editing, comparison and Graph visualization happen locally in your browser.
• No ads, tracking, telemetry or affiliate scripts.
• No geolocation requests or remote executable code.
• Your JSON is not uploaded to a GOSU JSON server.
• Public source code under the MIT license.
WEBSITE ACCESS AND REQUESTS
Website access allows automatic detection of JSON responses. You can choose whether JSON opens automatically on each site.
Opening an existing JSON response uses the page’s data without repeating the request. Using Open URL or Refresh makes a new request to the endpoint you choose and follows its redirects. These explicit requests omit session cookies and authentication credentials.
Edits affect your local document only. They do not update the API or server.
LIMITS AND SAVING
Documents support up to 10 MiB and 100,000 nodes. Graph expands children in blocks of 40 and displays up to 600 nodes at a time; this display limit does not remove data from your JSON.
Documents are not autosaved. Download your changes before closing the workspace.
TRY THE EXAMPLES
The GitHub repository includes a guided playground for Tree, Graph, Table, search, editing, exports, numeric precision and Diff.
SOURCE CODE AND EXAMPLES
https://github.com/jansanchez/gosu-json
SUPPORT AND FEATURE REQUESTS
https://github.com/jansanchez/gosu-json/issues
PRIVACY POLICY
https://github.com/jansanchez/gosu-json/blob/main/PRIVACY.md