Icons are a must in any software app. They will help guide your users quicker through your app. They also might help clean up your UI. Instead of “Open Menu” and “Close Menu” you can use ≡ and × (the “hamburger” is probably the most-known icon on the internet).
Luckily, in 2025, you don’t have to create any icons yourself anymore, because along side many great, commercial libraries there are some truly amazing libraries that are completely free.
I want to list some of them here to list, highlight, and thank them for their existence. Our apps look and work better because of them.
Hericons (300+ icons)
A carefully crafted icon set, with variants from outline to mini and even micro. This smaller variant shows the care they put in for details. The least number of icons, but should match most of your general SaaS needs.
Feather (280+ icons)
An outline-only set of icons. But with around 280 of them it’s a solid collection.
Lucide (1500+ icons)
Started as a fork of Feather mentioned above. As can see from the icon count has been growing steadily since.
Phosphor (9000+ icons)
A massive number of icons! Granted four variants are stroke-widths (and I couldn’t easily detect any manual tweaks between them). But even without the semi-duplicates ones, it’s still an awesome ~1500 icons per variant.
Radix (300+ icons)
An icon library by WorkOS. They mix a few solid icons with an other outline variant. It’s a pretty vast icon set, but designed to be used at fairly small size (which is usually fine for software apps).
Tabler (5700+ icons)
This huge icon set has two variants (for most icons): solid and outline.
The icon count is the total between all their variants. Most of these libraries provide the same icons in multiple variants, like solid, outline or fill. This is nice, because, for example, if you need to display some icons fairly small, an outline icon becomes less legible, than say a filled icon.
Let’s go over some more best practices.
Best practices
To keep things professional and good-looking there are a few things to keep in mind when using icons.
- stay consistent; ideally stick to one icon library;
- when using icon-only buttons (without a label); make sure to add a, eg.
aria-label="Search"; - Not every icon can increase or decrease in size without consequence; typically outlined icons work less when really small (< 14px);
How to add these icons to your app
All these mentioned icon libraries are open-source, meaning you can download them and use them in your app. Maybe following this article about inline svg icons. Also most have their own, dedicated gem you can pull into your app.
All great. But early last year, I wanted something better. One API for all these icon libraries (and then some). That’s when I created and published Rails Icons. It’s a simple gem that let’s you pull in the icons you want from their respective GitHub libraries, keeping the gem light-weight.
Is there one library missing from this page (and in Rails Icons)? Let me know.