1. Format first
Start by pretty-printing compressed payloads or log fragments so the structure and nesting become obvious.
No input
JSON Formatter/Validator
브라우저 내부 처리
Format, validate, minify, and inspect JSON with tree view support.
A practical way to use this JSON page
2. Search for the critical field
Search helps narrow large payloads down to a user ID, status flag, or nested key without scanning the whole response manually.
3. Use the tree for depth
The tree view is especially helpful when arrays and nested objects make plain formatted text harder to explain or screenshot.
JSON mistakes that show up all the time
Missing double quotes
JSON requires double quotes around keys and string values. JavaScript object syntax often causes confusion here.
Trailing commas
A trailing comma may look harmless, but standard JSON parsers reject it in both arrays and objects.
Sensitive payloads
This page runs in browser memory, but production secrets and personal data should still be masked before review when your internal policy requires it.
Common JSON formatter questions
How is JSON different from a JavaScript object?
JSON is a data exchange format. Keys and string values need double quotes, and comments or trailing commas are not valid.
Should I format or minify?
Format when humans need to read and review the payload. Minify when you need a compact one-line body or fixture.
Can large JSON payloads be handled in the browser?
Most API responses are fine, but very large files can affect browser memory and rendering. For huge logs, inspect the relevant slice first.
Which tools pair well with JSON Formatter?
Use JWT Decoder for token payloads, JSON YAML Converter for format handoff, and API Request Tester for reproducing requests.
Working with JSON
Large integers lose precision
JavaScript numbers are double-precision floats, so the safe integer range ends around 9 quadrillion. Snowflake IDs and 64-bit integers passed through JSON lose their last digits. Sending them as strings is the standard fix.
Comments and trailing commas are syntax errors
JSON has no comments and does not permit a trailing comma. Confusion with JavaScript object syntax is the usual cause. If a config file needs comments, use JSON5 or YAML, or add a dedicated description key.
Key order is not guaranteed
Object key order carries no meaning in the spec and can change through parse and serialise cycles. Data where order matters belongs in an array. Code comparing two JSON documents as strings fails for the same reason.
More: step-by-step usage and worked examples
JSON examples people paste most often
When you inspect API responses, config snippets, or logged payloads, separate “is this valid JSON?” from “does the shape match what I expected?” first.
API response formatting
Pretty-print compressed responses, then inspect status fields, pagination, and nested data positions.
{"ok":true,"data":{"user":{"id":42,"role":"admin"}}}
Config validation
Single quotes, trailing commas, and comments belong to JavaScript-like objects, not strict JSON.
{
"env": "prod",
"featureFlags": ["search", "export"]
}