Free tools for developers

Free SEO Checker

Enter any page and get an SEO score out of 100 with the fixes in order — title, description, headings, speed signals and structured data.

JSON Formatter & Validator

Format, validate and minify JSON in your browser. Shows the exact line of any error.

JWT Decoder

Decode a JSON Web Token header and payload, see expiry and warnings. Nothing is sent anywhere.

Regex Tester

Test a regular expression live, see every match and group highlighted.

Base64 Encode / Decode

Encode or decode Base64 text (UTF-8 safe) instantly in your browser.

Cron Expression Explainer

Turn a cron expression into plain words and check it is valid.

Text Diff Checker

Compare two texts or code snippets line by line and see what was added or removed.

UUID & Hash Generator

Create UUIDs and SHA-1, SHA-256 or SHA-512 hashes of any text, right in your browser.

Unix Timestamp Converter

Convert Unix timestamps to dates and back, in your time zone and in UTC.

.env File Checker

Check a .env file for duplicate keys, bad lines, empty values and secrets that look real.

Email DNS Check (SPF, DMARC, MX)

See if a domain has MX, SPF and DMARC records set, and what is missing for good email delivery.