What is the difference between JSON validation and JSON Schema?

Syntax validation proves the document can be parsed as JSON. JSON Schema can additionally require fields, enforce types and formats, and constrain values.

Why is a single-quoted string invalid?

JSON requires double quotes around strings and property names. Single quotes are accepted by JavaScript source code in some contexts but are not valid JSON.

Why does the error point after the real mistake?

A parser often discovers a problem only when the next token no longer fits. Inspect the preceding comma, quote, bracket, or escape sequence as well.

Does valid JSON guarantee an API request will succeed?

No. The server may still reject missing fields, incorrect types, invalid credentials, unsupported media types, or business-rule violations.

Formatting

JSON Validator

Validate & pretty print

All tools

JSON Validator how to for json validator: open the tool, run a tiny sample, then save the result.

DevsWallet

Automation Pipeline

STANDBY

Capture

Payload ready

Engine

API orchestration

Deliver

Structured result

Automation trace

Awaiting task…

JSON Validator

Paste JSON to check syntax and get a formatted version if valid.

Guide & documentation

How to use JSON Validator

DevsWallet JSON Validator checks whether text follows the strict JSON grammar and explains where parsing stopped. It is designed for the common gap between a payload that looks correct and one an API, package manager, or deployment tool can actually parse. Validation catches structural syntax errors; it does not prove that fields have the right business meaning. After syntax passes, use a JSON Schema or application-level checks to verify required properties, types, ranges, and allowed values.

JSON Validator runs in your browser on DevsWallet. Use the steps below for a first successful run, then open the full guide if you need deeper examples, FAQs, and troubleshooting.

Step by step

Paste the smallest payload that still reproduces the parsing problem.
Run validation and inspect the reported line, column, or character offset.
Correct one syntax issue at a time, starting with unmatched braces, quotes, escapes, and commas.
After syntax passes, compare the object against the receiving API’s schema and test it with non-production data.

Common use cases

Finding a trailing comma in a deployment or package configuration.
Checking webhook examples before adding them to documentation.
Separating JSON syntax errors from API schema-validation errors.
Validating test fixtures generated by scripts or spreadsheets.

Expert deep dive

Invalid JSON breaks APIs and config pipelines. Paste payloads to see precise syntax errors with line context before deployment.

Frequently asked questions

What is the difference between JSON validation and JSON Schema?: Syntax validation proves the document can be parsed as JSON. JSON Schema can additionally require fields, enforce types and formats, and constrain values.
Why is a single-quoted string invalid?: JSON requires double quotes around strings and property names. Single quotes are accepted by JavaScript source code in some contexts but are not valid JSON.
Why does the error point after the real mistake?: A parser often discovers a problem only when the next token no longer fits. Inspect the preceding comma, quote, bracket, or escape sequence as well.
Does valid JSON guarantee an API request will succeed?: No. The server may still reject missing fields, incorrect types, invalid credentials, unsupported media types, or business-rule violations.