What common JSON errors can the Auto-Repair Assistant fix?

The rule-based repair engine automatically resolves trailing commas before closing braces/brackets, single quotes ('') converted to standard double quotes (""), unquoted object keys, smart/curly quotes, JavaScript single-line and multi-line comments, Python literals (True, False, None), and missing terminal closing brackets.

Why does standard JSON disallow trailing commas and single quotes?

The official RFC 8259 JSON specification strictly mandates double quotes for all string literals and object keys, and prohibits trailing commas after the final element in an array or object. While JavaScript object literals allow them, valid interchange JSON does not.

How does the Copy Path feature work in Tree View?

When you switch to Tree View, each nested key and array index tracks its hierarchical path. Hovering over any element reveals a 'Copy Path' button that copies standard dot-notation paths (such as users[0].profile.email) directly to your clipboard.

Can this tool handle large JSON files offline?

Yes! Because the tool leverages modern native V8 JSON.parse and JSON.stringify algorithms directly in your browser, it handles large data sets quickly and functions seamlessly without an active internet connection.

JSON Formatter & Repair Assistant

Format, minify, validate, and auto-repair broken JSON with pinpoint error diagnostics, tree folding, and path copying.

Input JSON

18 lines•0.3 KB

✓ Valid Syntax

{

"product": "Crefims Pro",

"version": 1.2,

"features": [

"Smart Text Diff",

"Quick Notes",

"JSON Repair Assistant"

"settings": {

"theme": "system",

"offlineSupport": true,

"maxTokens": 4096

"metrics": {

"totalUsers": 12840,

"rating": 4.98

}

Indentation: 2 spaces

Capabilities

Key Features

Instant JSON formatting with configurable indentation (2 spaces or 4 spaces)
One-click JSON minification for fast payload transfer and reduced payload size
Deterministic rule-based Auto-Repair engine for trailing commas, quotes, and comments
Pinpoint line-and-column syntax error highlighting with plain-English diagnostics
Interactive collapsible Tree View with collapsible nodes and item counts
One-click JSON path copier (dot-notation & array indices) directly from tree nodes
Recursive alphabetical key sorting (A-Z) to normalize and compare object structures
Zero server uploads: runs entirely client-side using native JavaScript engine

Quick Guide

How to use

Paste your raw or broken JSON

Enter or paste your JSON snippet into the left editor. You can also click 'Load Broken Sample' to test the repair engine.

Format, minify, or sort keys

Click 'Format 2 Spaces' or 'Format 4 Spaces' to beautify your data, 'Minify' to compress, or 'Sort Keys (A-Z)' to alphabetize keys recursively.

Use Auto-Repair if syntax errors are detected

If your JSON has syntax errors (like trailing commas or unquoted keys), click 'Auto-Repair' to fix them deterministically.

Explore the Tree View and copy JSON paths

Switch to 'Tree View' to expand/collapse nested objects and copy exact path references (e.g. data.items[0].id) with a single click.

Technical Guide

About JSON Formatter & Repair Assistant

JSON Formatter & Repair Assistant is a high-speed, privacy-first developer utility to format, minify, validate, and automatically repair corrupted or broken JSON. Equipped with a rule-based syntax engine, it highlights exact error lines, explains what went wrong in plain English, and fixes common blunders like trailing commas, single quotes, unquoted object keys, and missing braces with a single click. All parsing runs 100% locally in your browser — your sensitive API payloads, tokens, and data never leave your device.

FAQ

Frequently Asked Questions

No. All parsing, validation, formatting, and auto-repairs are computed 100% inside your browser using client-side JavaScript. Your sensitive API payloads, database exports, credentials, and customer data never leave your machine.

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