JSON Validator
Find out whether JSON parses, and where it stops.
FREE - NO SIGN-UP - RUNS ON YOUR DEVICE
Checked in your own tab
- Line + colon failure
- Syntaxnot schema
- 0uploads
- Freeno account
What you can count on
- Lineand column
- Failures are located, not only announced
- Points at where parsing stopped
- Syntaxonly
- Says whether the text parses
- Not whether fields are missing
- 0uploads
- The JSON is checked inside this tab
- Nothing is sent for validation
JSON Validator at a glance
- Input
- Pasted JSON
- What is checked
- Whether the text parses
- On failure
- The line and column are named
- On success
- Valid, or where it stopped
- What it does not check
- Not schemas or required fields
- Price
- Free
- Account needed
- None
- Where processing happens
- On your device
How to use JSON Validator
- 1
Paste what you want checked
Put in the text you want checked, whether it came from a log, an API reply or a config file.
- 2
Read the verdict
It parses and reports Valid JSON, or the line and column where the parser stopped.
- 3
Fix and check again
Correct the character at that position and check again. Each pass moves to the next problem, if there is one.
Frequently asked questions
It says invalid but it looks fine.
Look at the reported position. A trailing comma before a closing bracket, a single quote instead of a double, or a smart quote pasted from a document are the usual causes.
Can it check my JSON against a schema?
No. It checks syntax only. Whether a required field is present, or a value is the right type, is a separate question this parser does not answer.
Does it accept comments in JSON?
No, and neither does JSON. Comments are a common extension in config files, and the parser here stops at the first one it meets.
Is the JSON sent anywhere to be checked?
No. The parser is the one built into your browser and it runs in this tab. Nothing is uploaded, logged or stored.
What usually breaks JSON
The browser's own parser reads what you paste. If it parses you get Valid JSON; if it does not, you get the position where the parse ended. Beautify returns the formatted text.
- A trailing comma after the last item is valid in JavaScript and not in JSON, and it is the most common failure.
- Single quotes are not JSON. Keys and string values both need double quotes.
- Quotes and dashes rewritten by a word processor look right and do not parse.
- A file that starts with a byte order mark can fail at line one, column one, before any data is read.
Full specification
| Input | JSON pasted into the box. |
|---|---|
| What is checked | Whether the text parses as JSON: brackets, commas, quoting, escapes and number forms. |
| On failure | The line and column where the parser stopped, which is the character to look at first. |
| On success | Valid, or the position of the error. Press Beautify for the formatted text. |
| What it does not check | Schemas. Required fields, value types and allowed ranges are outside what a parser knows. |
| Price | Free. Supported by clearly labeled ads outside the working area. |
| Account needed | No. |
| Where processing happens | In your browser tab. Your input is never uploaded. |
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