JSON Formatter & Validator — Beautify, Validate JSON Online
Line-numbered JSON editor with format, repair, share URL, load from URL, remove nulls, flatten, tree & table views, JSONPath, schema validation, and compare — all private in your browser.
Also searched as: json beautifier · json prettifier · json validator · json lint · json pretty print
How to Use
Step-by-step guide to get the most from this tool
- 1
Paste or load JSON
Paste JSON, upload a file, load from URL, or open a shared link.
- 2
Format or repair
Use Format, Smart beautify, Repair, or Auto-correct to fix syntax issues.
- 3
Explore or transform
Switch to Tree or Table view, run JSONPath queries, or validate against a schema.
- 4
Share or export
Copy output, download as .json, export CSV, or share a link with teammates.
Features
What makes this tool stand out
Line numbers
Editor with line numbers and error line highlighting.
Share & load URL
Share encoded links or fetch JSON from public APIs.
Tree & table views
Explore nested data visually with search.
Repair & transform
Auto-correct, remove nulls, flatten, sort keys.
Schema validation
Validate against custom JSON Schema.
Compare documents
Side-by-side diff with path highlighting.
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Frequently Asked Questions
Quick answers to common questions
How is this different from JSON Editor Online?+
ToolReign offers text/tree/table views, format, repair, query, schema validation, compare, share URLs, and load-from-URL — all private in your browser.
What does auto-correct JSON do?+
Auto-correct fixes trailing commas, single quotes, unquoted keys, comments, and other common mistakes, then normalizes with standard formatting.
How do I share JSON with a link?+
Click Share to copy a URL with your JSON encoded in the query string. Anyone opening the link sees the same input pre-filled.
Can I load JSON from an API URL?+
Click From URL and paste a public JSON endpoint. CORS must allow browser access; private APIs require pasting manually.
What does Remove nulls do?+
It strips null values from objects and arrays recursively, useful before sending payloads to APIs that reject null fields.
What does Flatten do?+
Flatten converts nested objects into dot-notation keys (e.g. meta.free) for flat CSV-style exports.
How do I compare two JSON documents?+
Click Compare, paste JSON in both panels, then switch to Tree mode. Differences are highlighted with a diff panel below.
Is my JSON data safe?+
Yes. All processing happens in your browser. No data is sent to any server unless you explicitly fetch a URL.