justuse.me

Developer Tools

Regex tester, URL encoder, CSS generators, and more.

Regex Tester

Test regular expressions and find all matches with positions in your text.

Timestamp Converter

Convert Unix timestamps to human-readable dates and vice versa, in multiple formats.

JSON to TypeScript

Convert a JSON object into TypeScript interface definitions, handling nested objects and arrays.

HTML to JSX

Convert HTML markup to JSX-compatible React syntax (className, htmlFor, self-closing tags, style objects).

chmod Calculator

Convert between numeric (755) and symbolic (rwxr-xr-x) Unix file permission formats with full explanation.

Meta Tag Generator

Generate complete HTML head meta tags including SEO, Open Graph, and Twitter Card tags.

CSS Gradient Generator

Generate CSS linear-gradient code from two colors and an optional direction or angle.

HTTP Status Codes

Look up HTTP status codes by number or keyword, with descriptions and common use cases.

CSS Box Shadow Generator

Generate CSS box-shadow code from offset, blur, spread, and color parameters.

CSS Flexbox Generator

Generate complete CSS flexbox code from direction, justify, align, wrap, and gap parameters.

Favicon Generator

Resize any image to a 32×32 PNG favicon ready for web use.

JSON Validator

Validate JSON and get a formatted, pretty-printed version or a detailed error with line number.

CSS Unit Converter

Convert CSS values between px, rem, em, pt, and vw units.

Color Contrast Checker

Check WCAG AA/AAA contrast ratio between foreground and background colors.

SVG Optimizer

Remove comments, metadata, empty groups, and unnecessary attributes to reduce SVG file size.