JSON Viewer & Formatter — Validate and Pretty Print JSON

What is a JSON Viewer?

A JSON viewer parses a JSON string and presents it in a structured, readable format. It shows indentation, highlights keys and values, detects syntax errors, and often provides a collapsible tree view for nested objects.

Why Use a JSON Viewer?

When debugging API responses, config files, or log entries, raw JSON is hard to read. A viewer formats it with correct indentation, makes errors obvious with highlighting, and lets you navigate nested structures by expanding/collapsing nodes.

Key Benefits

• Instant JSON formatting and pretty-printing
• Syntax error detection with line numbers
• Collapsible tree view for nested JSON
• Supports large payloads
• Copy formatted JSON with one click

How to Use JSON Viewer

1. Paste raw JSON into the input area
2. The formatted and validated output appears instantly
3. Expand/collapse nodes in the tree view
4. Copy the formatted JSON or fix errors highlighted in red

Example Use Case

You're debugging a REST API response. The server returns a minified JSON blob. Paste it into JSON Viewer — you instantly see the formatted structure, find the missing `user.address` field that's causing a null error, and understand the response shape.

Tips

• Use Ctrl+A to select all in the input before pasting new content
• JSON keys must be double-quoted — single quotes cause parse errors
• Trailing commas are not valid JSON
• Use YAML/JSON converter if you need YAML output of your JSON