There are several excellent tools available for web design prototyping, each with its own set of features and capabilities. Here are some of the best tools for web design prototyping:

1. Figma:
   • Figma is a cloud-based design and prototyping tool that allows for real-time collaboration. It offers a wide range of design and prototyping features, making it a popular choice for both individuals and teams.
2. Adobe XD:
   • Adobe XD is a powerful design and prototyping tool that integrates seamlessly with other Adobe Creative Cloud applications. It offers an intuitive interface and robust prototyping capabilities.
3. Sketch:
   • Sketch is a vector-based design tool for macOS that is particularly popular among UI/UX designers. While it is primarily a design tool, it offers basic prototyping features.
4. InVision:
   • InVision is a cloud-based prototyping tool that allows designers to create interactive and animated prototypes. It offers collaboration features and integrates well with design tools like Sketch and Adobe XD.
5. Axure RP:
   • Axure RP is a comprehensive prototyping tool that allows for advanced interactions and dynamic content. It’s suitable for creating complex, high-fidelity prototypes.
6. Proto.io:
   • Proto.io is a web-based prototyping platform that enables designers to create interactive prototypes without the need for coding. It offers a user-friendly interface and supports collaboration.
7. Balsamiq:
   • Balsamiq is a wireframing and low-fidelity prototyping tool that focuses on rapid sketching and ideation. It’s great for quickly visualizing concepts and user interfaces.
8. Marvel:
   • Marvel is a simple and intuitive prototyping tool that allows designers to create interactive and shareable prototypes. It’s suitable for designers of all skill levels.
9. Justinmind:
   • Justinmind is a prototyping tool that offers a wide range of interactive elements and features for creating high-fidelity prototypes. It’s suitable for designers working on complex web applications.
10. Framer:
    • Framer is a prototyping tool that allows for high-fidelity interactions and animations. It’s popular among designers who want to create rich and interactive user experiences.
11. Adobe Animate:
    • Adobe Animate is a powerful animation tool that can be used for creating interactive web prototypes. It’s particularly useful for projects that require complex animations.
12. Origami Studio:
    • Origami Studio is a prototyping tool developed by Facebook that focuses on creating interactive and animated interfaces. It’s especially useful for designers working on mobile app prototypes.
13. Flinto:
    • Flinto is a prototyping tool that enables designers to create interactive and animated prototypes for both web and mobile. It offers a range of features for creating seamless user experiences.

Choosing the right prototyping tool depends on your specific needs, preferences, and the complexity of your web design project. Many of these tools offer free trials or have free versions available, allowing you to explore them before committing to a paid subscription.