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About JSON Validator — Free Online Tool
JSON Validator tells you whether a document is valid JSON and, if it is not, exactly where it stops being valid — the line and the character.
It evaluates the text against the JSON grammar and reports the first point where the parse fails, with its position. The usual culprits are a trailing comma after the last item, a single quote where JSON requires double, and an unescaped quote inside a string — all legal in JavaScript, none legal in JSON, which is why they survive a glance and break an endpoint.
Validation happens in your browser, so a payload can be checked without sending it anywhere — including the payload that is failing precisely because it contains something sensitive.
Finding why an endpoint rejects a request body, checking a config file before a deploy, validating data a client sent you, and confirming a generated file is well formed.
Also known as: validate json · json linter · check json syntax · find json errors
When to use it
Instantly find trailing commas, unescaped quotes, or bad brackets that cause API endpoints to crash.
How it works
Evaluates character tokens and catches SyntaxErrors with exact line and column numbers.
Common Errors Caught
Trailing commas in arrays, single quotes instead of double quotes, and unquoted keys.
How to Use JSON Validator in 4 Easy Steps
Follow this simple guide to process your files in seconds directly inside your browser tab.
Provide Input for JSON Validator
Paste your payload, code snippet, or string into the JSON Validator editor workspace. Grammar validator that verifies whether a string conforms to JSON schema and syntax standards.
Configure Formatting & Validation Rules
Select indentation preferences, minification, encoding options, or validation rules. Instantly find trailing commas, unescaped quotes, or bad brackets that cause API endpoints to crash.
Run In-Browser Engine
The engine executes JSON Validator locally in your browser with microsecond latency and zero server transmission.
Copy or Download Output
Copy the sanitized, formatted, or generated output directly to your clipboard or download it for your project.
Why Use JSON Validator on ShortTrick
Engineered for maximum speed, strict privacy, and frictionless digital productivity.
Zero Code or Token Leaks
Proprietary source code, API keys, database queries, and tokens processed in JSON Validator never leave your browser.
Microsecond Performance
Optimized AST parsers and Web Crypto APIs process large payloads in JSON Validator in milliseconds.
No Paywall or Account
Built for developers to use JSON Validator instantly without sign-up friction or rate limits.
Syntax Validation & Formatting
JSON Validator highlights syntax errors and enforces standard formatting conventions automatically.
Offline Ready
Once loaded, JSON Validator functions entirely offline without requiring an active internet connection.
Dark Mode Optimized
High-contrast typography designed for effortless reading during coding sessions.
Frequently Asked Questions About JSON Validator
Common questions regarding JSON Validator, data privacy, file format compatibility, and usage limits.
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