Free developer tools

A fast, private toolkit for everyday development — format and validate code and data, decode tokens, test regular expressions, explain cron schedules, and more. No sign-up, nothing uploaded.

12 tools · free · no sign-up

JSON Formatter

Format, validate, and minify JSON — instantly, in your browser.

SQL Formatter

Beautify and format SQL queries for any dialect.

XML Formatter

Beautify, indent, and validate XML.

Code Beautifier

Format JavaScript, CSS, HTML, and JSON.

JSON to TypeScript

Generate TypeScript types from JSON.

JWT Decoder

Decode and inspect JSON Web Token header and payload.

Regex Tester

Test regular expressions against sample text with live matches.

Cron Expression Explainer

Translate a cron expression into plain English.

Chmod Calculator

Convert file permissions between octal and symbolic.

CIDR / Subnet Calculator

Calculate subnet range, mask, and host counts from CIDR.

Credit Card Validator (Luhn)

Check a card number's Luhn checksum and detect its brand.

Password Strength Checker

Test how strong a password is, privately.

Frequently asked questions

Do these tools send my data anywhere?

No. Every developer tool runs entirely in your browser — your code, tokens, and data never leave your device.

Is the JWT decoder safe to use?

Yes — decoding happens locally in your browser, so your tokens are never transmitted or stored.

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