Figma is Awesome.
Figma is awesome. Really, it is. We use Figma to create prototypes of our bespoke websites before we start coding.
With Figma, you can design, storyboard, animate (within a few limitations) and link together a full preview of a site before typing a single line of code. You can even add in responsive elements to get a better idea of how things will scale in the browser.
Figma, also starts out free although it has a paid subscription which offers some added benefits. It also has a great team behind it which are constantly pushing out updates almost fortnightly.
One of the best features is the ability to screen share your designs with the client so you can point and move things in real time to get a clear picture of how the site should look.
Figma is also built with front end devs in mind too. If you create a style in Figma, you can just copy and paste the CSS into your project so you can hit the ground running.