Developer Tools
Format JSON, test regular expressions, decode JWTs, build cron schedules, and more — the everyday utilities developers reach for, all free and running entirely in your browser. No signup, no rate limits, and nothing you paste ever leaves your device.
Placeholder Image Generator
Generate placeholder images at any size with custom colors and text. Download PNG, JPG, or SVG — free for developers and designers.
Use tool →QR Code Generator
Generate QR codes for URLs, text, WiFi, email, and more. Customize colors, add logos, download as PNG or SVG — free online.
Use tool →Password Generator
Generate strong, random passwords instantly. Customize length and character types. Uses crypto.getRandomValues() for true randomness. Nothing is stored or transmitted.
Use tool →JSON Formatter & Validator
Format, validate, and minify JSON instantly. Syntax highlighting, error detection with line numbers, and stats. Free online JSON formatter — your data never leaves your browser.
Use tool →Diff Checker
Compare two texts and see every difference highlighted. Line-by-line diff with additions, deletions, and modifications color-coded. Free, private, runs in your browser.
Use tool →Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to plain text instantly. Handles Unicode correctly, runs 100% in your browser — nothing is uploaded.
Use tool →URL Encoder / Decoder
Percent-encode text for URLs or decode encoded URLs back to readable text. Choose encodeURIComponent or encodeURI. Free, instant, 100% in-browser.
Use tool →Regex Tester
Test regular expressions live against your own text. See highlighted matches, capture groups, and clear error messages. Free and 100% in-browser.
Use tool →Cron Expression Builder
Build cron expressions with dropdowns or paste one to decode it. Get a plain-English description and the next 5 run times in your timezone. Free.
Use tool →JWT Decoder
Decode JWT tokens instantly in your browser. See the header, payload claims, and expiry with readable timestamps. Tokens never leave your machine.
Use tool →UUID Generator
Generate cryptographically secure v4 UUIDs in bulk — 1 to 50 at a time. Uppercase and no-hyphen options, one-click copy. Free and 100% in-browser.
Use tool →Markdown Previewer
Write markdown and see the rendered result live, side by side. Supports tables, code blocks, and lists. Copy clean HTML. Free, 100% in-browser.
Use tool →HTML Entity Encoder / Decoder
Convert special characters to HTML entities like & and ©, or decode named, decimal, and hex entities back to text. Free, 100% in-browser.
Use tool →Color Picker & Converter
Pick any color visually and convert between HEX, RGB, HSL, and CMYK instantly. Edit any format and the rest update live. Free, 100% in-browser.
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