Developer Tools
A toolbox for everyday developer and sysadmin work: decode and verify a JWT, test a regular expression with highlighted matches, read a cron expression, compute a hash, generate a UUID or convert a Unix timestamp.
Everything runs locally in your browser, with no account and no network calls — so you can paste an auth token or a sensitive payload with no risk of leaking it. Perfect while debugging, reading logs or fine-tuning a config.
Convert Unix timestamps to readable dates and back.
Parse a cron expression and preview the next execution times.
Test regular expressions with highlighted match visualization.
Inspect the HTTP response headers of any public URL.
Convert numbers between binary, octal, decimal and hexadecimal.
Convert colors between HEX, RGB and HSL formats.
Generate a QR code from text or a URL.
Generate TypeScript interfaces from JSON.
Generate Go structs from JSON.
Generate HTML meta tags for SEO and social networks.
Find your IP address and its information.
Estimate the number of LLM tokens in a prompt (GPT, Claude).
Check an IBAN, a French SIRET/SIREN or VAT number.
Generate CSS gradients and shadows with a live preview.
Hex, binary, int64, float and ASCII with endianness.