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
Show your public IP address and its details
Estimate the number of LLM tokens in a prompt (GPT, Claude)
Check an IBAN, a French SIRET/SIREN or VAT number
Build multi-color CSS gradients (linear, radial, conic)
Hex, binary, int64, float and ASCII with endianness
Edit a folder from your PC in the browser - local and private
Build multi-layer CSS shadows with a live preview
wa.me click-to-chat link + QR
Convert curl to fetch, axios, Python, Go…
Unix permissions: octal 755 ↔ symbolic rwx
Format and indent your SQL queries
Minify your CSS
Create EAN, UPC, Code128 barcodes…
Build UTM campaign links + QR
Build a cron expression visually
Minify or beautify JavaScript with Terser
Palettes, harmonies, shades and WCAG contrast from one color
Generate an Apache .htaccess (HTTPS, redirects, security, cache)
Open an .eml file: headers, sanitized HTML body, attachments
Create CSS gradients (linear/radial/conic) with live preview, CSS + Tailwind export