Developer Tools
Developer utilities in your browser: Base64, URL encode, JWT decoder, regex tester, hash generator, UUID, cron explainer, minifiers, chmod and more.
PX to REM Converter
Convert pixels to rem and em, and back, with a custom root font size. Includes a table of common sizes from 8px to 64px and a copy-ready CSS declaration.
Open toolBase64 Encode & Decode
Encode text to Base64 or decode Base64 back to text. Supports UTF-8 and URL-safe Base64. Free, instant and runs in your browser.
Open toolURL Encode & Decode
Encode or decode URLs and query strings with percent-encoding. Choose component or full-URL mode. Free, instant and private.
Open toolUUID Generator
Generate random version 4 UUIDs (GUIDs) in bulk. Copy one or hundreds, in uppercase or without hyphens. Uses your browser’s secure random generator.
Open toolHash Generator (SHA-256)
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes for text or files. Verify downloads and checksums. Runs locally in your browser.
Open toolJWT Decoder
Decode a JWT to read its header, payload and expiry time. Free and runs locally, so your token is never sent to a server.
Open toolRegex Tester
Test JavaScript regular expressions live. See matches highlighted, capture groups and indexes, with flags for global, case-insensitive and more.
Open toolUnix Timestamp Converter
Convert Unix timestamps (seconds or milliseconds) to human-readable dates and back. Shows UTC, ISO 8601 and local time. Live current epoch.
Open toolColor Converter
Convert colours between HEX, RGB and HSL with a live preview and colour picker. Copy ready-to-use CSS values. Free web colour converter.
Open toolHTML Entities Encode/Decode
Encode special characters to HTML entities or decode named and numeric entities back to text. Named, decimal and hex output. Safe and private in your browser.
Open toolCSS Minifier & Beautifier
Minify CSS by removing comments and whitespace, see the exact percentage saved, or switch to beautify mode to format compressed stylesheets. Private, instant.
Open toolJavaScript Minifier
Minify JavaScript in your browser with Terser: mangle names, compress code, drop console calls, see size saved and get clear syntax errors with line numbers.
Open toolHTML Minifier
Minify HTML by removing comments and collapsing whitespace between tags, while leaving pre, textarea, script and style content untouched. Shows bytes saved.
Open toolCSS Gradient Generator
Build linear, radial and conic CSS gradients with up to five colour stops, angle and position controls, a live preview and copy-ready CSS code.
Open toolBox Shadow Generator
Create CSS box-shadow code with multiple layers, inset shadows, blur, spread, colour and opacity controls and a live preview. Copy the CSS in one click.
Open toolCron Expression Explainer
Translate any 5-field cron expression into plain English, validate it, and see the next five run times in your time zone or UTC. Includes handy presets.
Open toolNumber Base Converter
Convert numbers between binary, octal, decimal, hexadecimal and any custom base from 2 to 36. Two-way live fields, BigInt precision and input validation.
Open toolChmod Calculator
Tick read, write and execute boxes for owner, group and others to get the chmod octal number and symbolic form. Includes setuid, setgid, sticky and presets.
Open toolMeta Tag Generator
Generate copy-ready HTML meta tags: title, description, canonical, robots, Open Graph and Twitter card, with live character counters and a Google preview.
Open toolAbout these developer tools
These are the small utilities developers reach for several times a week: encoding and decoding, inspecting tokens, testing a pattern, hashing a file, converting timestamps and colours, and shrinking CSS, JavaScript or HTML for production.
They run entirely client-side, so tokens, keys and snippets you paste are never logged or uploaded. Each page explains the concept behind the tool and the common mistakes to avoid.