What is the difference between UUID v1 and v4?

UUID v1 encodes the current timestamp and a node identifier (typically a MAC address or random value), making each UUID sortable by creation time. UUID v4 uses 122 random bits with no time or node component, making it completely opaque. Use v4 when you do not want to leak creation time or machine identity; use v1 when sortability by insertion order is useful, for example as a database primary key in distributed systems.

What formats does the color picker output?

The color picker outputs the selected colour in three formats simultaneously: HEX (e.g. #4f46e5), RGB (e.g. rgb(79, 70, 229)), and HSL (e.g. hsl(243, 75%, 59%)). Each format has a one-click copy button. HEX is the most common in CSS; RGB is used by most charting and canvas libraries; HSL is easier to reason about for adjusting lightness and saturation.

What can I encode in a QR code?

QR codes can encode any text string up to a few thousand characters, depending on the error correction level. Common uses include URLs, plain text messages, email addresses (mailto: links), phone numbers (tel: links), SMS templates (smsto: links), Wi-Fi credentials (WIFI: format), and vCard contact details.

Are the generated UUIDs truly unique?

UUID v4 uses 122 bits of randomness from the browser's cryptographically secure random source. The probability of a collision between two randomly generated v4 UUIDs is approximately 1 in 5.3 × 10^36, making collisions astronomically unlikely in practice. For most applications, UUIDs can be treated as globally unique without a central coordinator.

Visual & ID Generation Tools

3 free browser-based tools

Visual and identifier tools bridge design, content, and data needs. The color picker converts between HEX, RGB, and HSL so you can move colour values between CSS stylesheets, design tokens, and charting libraries without manual calculation. The QR code generator encodes any URL, plain text, contact detail, or Wi-Fi credential into a downloadable PNG entirely in the browser. The UUID generator produces version 4 (random) and version 1 (time-based) identifiers in bulk — ready to use as database primary keys, idempotency tokens, or session identifiers.

Free online visual and ID generation tools — color picker, QR code generator, and UUID generator. Fast, browser-based, no signup required.

Color Picker and Hex Generator

Pick any color and instantly get its HEX, RGB, and HSL values — with one-click copy for each format.

UUID Generator

Generate UUIDs v1 (time-based) and v4 (random) — single or in bulk, copy with one click.

QR Code Generator

Generate a QR code from any text, URL, email, or phone number — download it as a PNG instantly, no account needed.

Frequently asked questions

What is the difference between UUID v1 and v4?: UUID v1 encodes the current timestamp and a node identifier (typically a MAC address or random value), making each UUID sortable by creation time. UUID v4 uses 122 random bits with no time or node component, making it completely opaque. Use v4 when you do not want to leak creation time or machine identity; use v1 when sortability by insertion order is useful, for example as a database primary key in distributed systems.
What formats does the color picker output?: The color picker outputs the selected colour in three formats simultaneously: HEX (e.g. #4f46e5), RGB (e.g. rgb(79, 70, 229)), and HSL (e.g. hsl(243, 75%, 59%)). Each format has a one-click copy button. HEX is the most common in CSS; RGB is used by most charting and canvas libraries; HSL is easier to reason about for adjusting lightness and saturation.
What can I encode in a QR code?: QR codes can encode any text string up to a few thousand characters, depending on the error correction level. Common uses include URLs, plain text messages, email addresses (mailto: links), phone numbers (tel: links), SMS templates (smsto: links), Wi-Fi credentials (WIFI: format), and vCard contact details.
Are the generated UUIDs truly unique?: UUID v4 uses 122 bits of randomness from the browser's cryptographically secure random source. The probability of a collision between two randomly generated v4 UUIDs is approximately 1 in 5.3 × 10^36, making collisions astronomically unlikely in practice. For most applications, UUIDs can be treated as globally unique without a central coordinator.