Developer tools that stay on your machine

Format JSON, convert timestamps, generate UUIDs, and test regular expressions — all in the browser, with no accounts and no uploads.

JSON Formatter Timestamp UUID Regex

JSON Formatter & Validator

Format, minify, or validate JSON. Processing stays in your browser.

Input

0 characters

Indent

Output

No output

Paste JSON or load the sample to begin.

Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates. Supports seconds and milliseconds.

Timestamp → Date

Unix timestamp

Enter a numeric timestamp. Values ≥ 1e12 are treated as milliseconds.

Date → Timestamp

Date and time

UUID v4 Generator

Generate cryptographically random UUID version 4 identifiers.

Number of UUIDs

Uppercase output

Regular Expression Tester

Test JavaScript regular expressions. View matches, indices, and capture groups.

Pattern

Flags

Test text

Privacy

All four tools run entirely in your browser. Input is not sent to a server. Clipboard and secure random number generation may require HTTPS or localhost. Avoid pasting secrets into any tool you do not trust.