The tool every developer opens daily
An API response crammed into one line, a config that won't parse, a payload you need to shrink before shipping — JSON formatting is the most-reached-for utility in a developer's day. This one does the essential trio: pretty-print with 2 or 4 spaces, validate with an error message that points at the line, and minify to the smallest valid form.
Unlike most online formatters, this page sends nothing anywhere — and that matters, because the JSON developers paste is full of API keys, tokens and customer data. Here it stays in the textarea. The formatter is plain JSON.parse/stringify — the same strict standard your runtime uses.
Frequently asked questions
Does it support JSON5 or comments?
No — this is strict standard JSON, the same rules as
JSON.parse. Comments and trailing commas are flagged as errors, which is exactly what you want when validating for production.How large a JSON can it handle?
Multi-megabyte payloads format instantly; very large ones are limited only by browser memory.
Can it sort keys or convert to YAML?
Key sorting is on the roadmap. For YAML conversion, use our YAML ⇄ JSON tool — it's one click away in Related tools.