Best Cardinal CSS Alternatives & Competitors in 2025

A set of small, responsive CSS modules that you can use in every web project.

Key Purecss features:

Lightweight Responsive Modular Easy Integration

Open Source

Simple and flexible HTML, CSS, and JS for popular UI components and interactions.

Key Bootstrap features:

Responsive Design Pre-designed Components Cross-browser Compatibility Extensive Documentation

Open Source

Monitor all your cloud services with our status page aggregator. IT teams choose IsDown to monitor all their vendors and get alerts whenever an outage occurs. Integration with Datadog, PagerDuty, Slack, Microsoft Teams, and a lot more.

Key IsDown.app features:

Status Dashboard Multiple Profiles for same account Slack App Zapier Integration

Try for free paid Free Trial $37.0 / Monthly (Pro)

A modern responsive front-end framework based on Material Design.

Key Materialize CSS features:

Responsive Design Material Design Component Variety Customization

Open Source

A lightweight and modular front-end framework for developing fast and powerful web interfaces.

Key UIKit features:

Modularity Extensive Documentation Responsive Design Customization

Open Source

A Beautiful Boilerplate for Responsive, Mobile-Friendly Development.

Key Skeleton CSS features:

Lightweight Simplicity Responsive Grid Clean Design

Open Source

The most advanced responsive front-end framework in the world.

Key Foundation features:

Customizability Responsive Design Semantic Code Range of Components

Open Source

Bulma is an open source CSS framework based on Flexbox and built with Sass. It's 100% responsive, fully modular, and available for free.

Key Bulma features:

Simple and Elegant Design Responsive Layouts Ease of Use BEM Methodology

Open Source

A utility-first CSS framework for rapidly building custom user interfaces.

Key Tailwind CSS features:

Utility-First Approach Customization Consistent Design Responsive Design

Open Source

Mockingbird helps you you create and share clickable wireframes. Use it to make mockups of your website or application in minutes.

Key mockingbird features:

User-Friendly Interface Collaboration Features Cloud-Based Access Interactive Prototypes

Open Source

Exploratory analysis you can share.

Key Mode Python Notebooks features:

Integrated with Mode Analytics Real-time Collaboration Accessible via Web Interface Built-in Visualization Tools

Real walkie-talkie on smartphone. Chat with nearby (10-15km).

Key Salute! Modern Walkie-Talkie for drivers features:

Hands-Free Communication Noise Reduction Technology Real-Time Connectivity Long Battery Life

Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.

Key Duolingo features:

Gamification Accessibility Free Tier Variety of Languages

JS-powered run-time CSS.