ICON OOP brings together five of the most widely used open-source icon collections. They are all free and all high quality, but they each have a distinct personality and a job they do best. This page explains what each one is, where it shines, and what licence it carries - so you can pick the right set with confidence.
Lucide
What it is: Lucide is a collection of more than 1,700 clean, consistent outline icons for user interfaces. It grew out of the popular Feather icon set and is actively maintained by a large community.
Best for: Modern web apps and dashboards that want a light, friendly, uncluttered look. Every icon is drawn on the same grid with the same stroke weight, so a screenful of Lucide icons always looks tidy.
Style: Outline only, rounded corners, 24×24 grid, adjustable stroke width. Licence: ISC, which is a short permissive licence very similar to MIT. Free for commercial use.
Tabler
What it is: Tabler is the largest interface set in ICON OOP, with over 5,000 icons. Many icons come in both an outline and a solid filled version.
Best for: Projects that need an icon for almost anything. Because the set is so large, you can usually find a specific, less common concept without having to compromise. The filled variants are handy for active or selected states.
Style: Outline and filled, 24×24 grid, adjustable stroke width. Licence: MIT. Free for commercial use.
Phosphor
What it is: Phosphor is a flexible icon family. Every icon is drawn in six different weights - thin, light, regular, bold, fill and duotone - which together produce around 9,000 variants.
Best for: Designs that want personality and a precise visual weight. The thin weight feels elegant and editorial; the bold and fill weights read clearly at small sizes; duotone adds a subtle two-tone accent.
Style: Six weights, 256×256 grid. Licence: MIT. Free for commercial use.
Material Symbols
What it is: Material Symbols is Google's official interface icon system, with over 3,800 symbols. It is the icon language used across Google's own products and Android.
Best for: Android apps, products built with Material Design, or any interface where users already expect Google-style icons. Choosing Material Symbols makes an app feel instantly familiar to a huge number of people.
Style: Outline, 24×24 grid. Licence: Apache 2.0. Free for commercial use.
Simple Icons
What it is: Simple Icons is a collection of more than 3,400 brand and company logos - single-colour, simplified marks for software, services and well-known organisations.
Best for: Login buttons, technology stacks, partner lists, footers and anywhere you need to show that your product works with a named service. Each logo also carries its official brand colour, which ICON OOP can apply with one click.
Style: Single-colour brand marks. Licence: CC0 for the icon files. Note that the logos and brand names themselves remain trademarks of their owners - see the licensing guide.
How to choose between them
A simple way to decide:
| If you need… | Reach for |
|---|---|
| A tidy, lightweight UI look | Lucide |
| The widest possible choice of icons | Tabler |
| Control over visual weight, or a duotone accent | Phosphor |
| A Google or Android-native feel | Material Symbols |
| A company or product logo | Simple Icons |
One important tip: within a single screen, try to use icons from just one set. Mixing outline styles from different families is the most common reason an interface looks slightly “off” even when nothing is obviously wrong. Brand logos from Simple Icons are the exception - they naturally sit alongside any UI set.