Sellible · 11 Tools

Design Tools

Explore focused tools for Design Tools, with simple browser-first workflows and clear results.

11 focused tools are available in this category. Browser-first utilities remain fast and free; protected file-processing tools use the shared account and credit system.

11 toolsSearch above or browse in quick batches.
Design Tools

Aspect Ratio Calculator

Scale width or height while preserving an aspect ratio.

Design Tools

Colour Contrast Checker

Calculate WCAG contrast ratio for two HEX colours.

Design Tools

CSS Button Generator

Create and preview accessible CSS button styles.

Design Tools

DPI Calculator

Calculate print DPI from pixel dimensions and physical size.

Design Tools

HEX to RGB Converter

Convert valid three, six or eight-digit HEX colours to RGB values.

Design Tools

HSL to RGB Converter

Convert hue, saturation and lightness into RGB values.

Design Tools

Image Resolution Calculator

Calculate megapixels, pixel count and print dimensions from resolution.

Design Tools

Placeholder Image Generator

Create a downloadable SVG placeholder with custom dimensions, colours and label.

Design Tools

RGB to HEX Converter

Convert red, green and blue channel values into a HEX colour.

Design Tools

RGB to HSL Converter

Convert RGB channels into hue, saturation and lightness.

Design Tools

Social Image Size Guide

Compare commonly used social image dimensions and aspect ratios.