---
title: "JSON Validator: Is My JSON Valid? Check Online | ToolSugar"
description: "Check whether JSON is valid and get a plain verdict first. Invalid input shows the line and column of the first error. It runs in your browser."
canonical: https://toolsugar.com/tools/json-validator
image: https://toolsugar.com/og.png
---

# JSON Validator

This JSON validator tells you whether a piece of text is valid JSON and leads with that verdict. A valid document is described by its top level type and size. An invalid one shows the line and column of the first syntax error. It runs in your browser and uploads nothing.

Runs on your device

## How it works

1. Paste your JSON into the JSON box, or open a file.
2. Read the Verdict box: it starts with Valid JSON, or the red message says Invalid JSON.
3. For an error, go to the line and column it names and fix that spot.
4. Switch Action to Format when you also want it pretty printed.

## Key facts

- **Where it runs**: In your browser tab. The text and files you use are never uploaded.
- **Live result**: The output updates as you type or paste, with no button to press.
- **Standard**: Strict JSON as parsed by your browser. Comments and trailing commas are not valid.
- **Valid result**: Reports the top level type, such as an object with 3 keys or an array with 12 items.

## Common uses

- Checking a webhook body or fixture before you commit it.
- Confirming that hand edited config still parses.
- Telling a teammate exactly where their JSON breaks.

## Questions

### How can I tell if a string is valid JSON?

Paste it here. The verdict appears at once: Valid JSON with the top level type, or Invalid JSON with the line and column of the first error.

### Why does my JSON fail when it looks fine?

The usual causes are a trailing comma, single quotes instead of double quotes, an unquoted key, or a missing bracket. The reported line and column point at the first character the parser could not accept.

### Does it check my data against a schema?

No. It only checks that the text is well formed JSON. It does not compare keys or types with a JSON Schema.

[Read the JSON Validator guide](https://toolsugar.com/blog/how-to-format-json)

## Related tools

- [JSON Formatter](https://toolsugar.com/tools/json-formatter)
- [JSON to YAML](https://toolsugar.com/tools/json-to-yaml)
- [YAML to JSON](https://toolsugar.com/tools/yaml-to-json)
- [JSON to CSV](https://toolsugar.com/tools/json-to-csv)