A wide range of generators for developers and designers: UUID generation (v1/v4/v7), QR code creation, secure password generation, hash computation (MD5/SHA-1/SHA-256/SHA-512), CSS gradient/Flexbox/animation/box-shadow generation, color palettes, unit conversion, tax calculation, bill splitting, and more.
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Generate QR codes for URLs, text, or any content. Custom colors and size. Download as PNG.
Generate UUID v1 or v4 with one click. Supports bulk generation and CSV export.
Generate barcodes in CODE128, EAN-13, EAN-8, UPC, CODE39, and more formats. Download as SVG or PNG.
Visually create linear and radial CSS gradients. Adjust angle, colors, and color stops with live preview.
Generate random strings with custom length, character sets (alphanumeric, hex, symbols). Bulk generation supported.
Convert date and time across 20+ worldwide timezones at once. UTC, US, Europe, Asia, and more.
Generate cryptographic hashes (MD5, SHA-1, SHA-256, SHA-512) from text or files instantly in your browser.
Generate OGP/social share images (1200×630px) in your browser. Custom title, subtitle, colors, and download as PNG.
Convert units of length, weight, temperature, area, volume, and speed. All conversions shown at once.
Generate UUID version 1 (time-based) UUIDs in bulk. Copy individual or all at once.
Generate UUID version 7 (time-ordered) UUIDs. Millisecond-precision sortable identifiers.
Build Flexbox layouts visually. Set flex-direction, justify-content, align-items, wrap, and gap with live preview.
Check color contrast ratios against WCAG AA and AAA standards. Pass/fail for normal text, large text, and UI components.
Generate color palettes from a base color: complementary, triadic, analogous, tetradic, and shades.
Generate random color palettes with one click. Lock colors to keep them while regenerating others.
Generate CSS animations visually. Choose from 8 presets or customize timing, easing, and iteration count.
Generate CSS box-shadow values with visual controls. Adjust offset, blur, spread, color, and inset.
Visually generate CSS clip-path values (circle, ellipse, polygon, inset) with live preview.
Calculate your exact age in years, months, and days from your birthdate. Next birthday countdown included.
Calculate price including or excluding tax with custom tax rate. Both forward and reverse (back-calculation) supported.
Calculate percentages: X% of Y, what % is X of Y, and percentage change between two numbers.
Calculate aspect ratios and scale dimensions. Find missing width or height from a given ratio.
Split a bill among multiple people with custom tip percentage. Per-person amount calculated instantly.
Generate strong, random passwords with uppercase, lowercase, numbers, and symbols.
Generate random integers or decimals in a custom range. Unique number mode with bulk output.
Everything about ISO 8601 — the YYYY-MM-DDTHH:mm:ssZ format, timezone offsets (Z vs +00:00), durations, week numbers, and how to use it in JavaScript, Python, PHP, SQL, and HTML.
A practical guide to 1D barcode formats — how CODE128, EAN-13, EAN-8, and UPC-A differ, how the check digit algorithm works, print-quality tips (SVG vs PNG), GS1 registration requirements, and how to generate barcodes free in your browser.
What makes a strong password — length requirements, character types, passphrase vs random password, password managers, and how to check your password strength. Includes a free password generator tool.
A developer's guide to UUID — how v4 random generation works, when to use v1 vs v5 vs v7, the difference between UUID and GUID, and best practices for storing UUIDs as database primary keys.
The complete reference for CSS gradients — syntax, color stops with position %, transparency, gradient text, border effects, and layered backgrounds. Includes copy-ready code for linear-gradient, radial-gradient, and conic-gradient.
Understand the three color formats used in CSS — HEX, RGB, and HSL. Covers when to use each, how to add opacity with rgba() and hsla(), 8-digit hex with alpha, and converting between formats.
Timezone bugs are subtle and painful. Learn the difference between UTC offsets and named zones, why you should always store UTC in your database, and how to handle DST correctly in JavaScript and Python.
Understand color contrast ratios and WCAG AA/AAA requirements. Covers the 4.5:1 threshold, how to find darker shades that pass, common failures like light-gray text, and tools to verify your palette before launch.
A clear, example-driven Flexbox guide. Learn justify-content vs align-items, how to center anything in two lines, flex-wrap for responsive layouts, and the flex shorthand for controlling how items grow and shrink.
Amida Kuji (ladder lottery) is a fair drawing method used across Japan. Learn how the vertical and horizontal lines determine outcomes, why it produces unbiased results, and how to create one digitally.
An online roulette wheel is a fast, fair way to make decisions. Learn how to set it up for task assignments, turn orders, lunch picks, and classroom activities — and why random selection removes friction.
Paper lotteries are slow and easy to rig. Learn how to run fair online drawings using ladder lottery, roulette wheels, and random number tools — with practical examples for teams, classrooms, and giveaways.
Learn what a UUID is and when to use each version. Covers v1 (time-based), v4 (random), and v7 (sortable), with practical guidance on database primary keys vs auto-increment IDs.
A clear explanation of cryptographic hashing. Covers MD5, SHA-1, SHA-256 and SHA-512 compared, why passwords are hashed not encrypted, and what hash collisions mean in practice.
A practical guide to generating QR codes. Covers linking to URLs, business cards, menus, and events — plus error correction levels, minimum print sizes, and whether to use short URLs.
Understand Unix timestamps from first principles. Learn what epoch time is, how to convert between timestamps and human-readable dates in JavaScript, Python, and PHP, and what the Year 2038 problem means.
UUID v4 is the go-to choice for database record IDs and API keys. QR codes are great for sharing links quickly without typing. Both generate instantly with one click.