Format, validate, and pretty-print JSON directly in your browser. It is useful for API responses, logs, webhook payloads, and sensitive JSON you do not want to upload.
Privacy note: this tool runs in your browser; inputs are not uploaded. How privacy works
Compact API responses and logs become easier to scan when nested objects and arrays are indented.
Input
{"user":{"id":123,"name":"Ada"},"active":true}Output
{
"user": {
"id": 123,
"name": "Ada"
},
"active": true
}JSON is parsed and formatted in the browser runtime. The pasted payload is not sent to a LocalTools server by this tool.
How LocalTools handles local and server-assisted toolsA practical workflow for inspecting API responses, logs, and webhook payloads locally.
A practical hub for choosing browser-local tools when working with JSON, JWTs, PDFs, images, hashes, and other data you hesitate to paste online.
A JWT debugging hub for decoding tokens, checking expiration, inspecting claims, and understanding why decoded does not mean trusted.
A practical safety checklist for formatting JSON that may contain API responses, logs, tokens, emails, or customer data.
Validate and inspect JSON API responses locally before adding payloads to code, docs, tests, or support tickets.
Inspect JWT headers, payloads, and claims in your browser without uploading the token to a third-party decoder.
Use exp, iat, and nbf claims to debug expired or not-yet-valid JWTs without uploading the token.
A safety checklist for decoding JWTs, understanding token sensitivity, and choosing local inspection over upload-based tools.
No. The JSON Formatter runs in your browser, so pasted JSON stays on your device.
The tool is designed for local formatting. You should still avoid pasting secrets into browser extensions or pages you do not trust.
Yes. Invalid JSON returns a parsing error instead of formatted output.
Standard JSON does not allow trailing commas after the last object property or array item.