What Is an Icon Library and How Do You Choose One for Your Project?

Updated

An icon library is a maintained package of icons that share one design language, plus the tooling to install or import them. Choose one when you need visual consistency across many screens and want updates handled for you; choose a single icon set (a fixed batch of files) when you only need a handful of icons and will never update them. IconShelf, for example, aggregates 300k+ icons from 236+ libraries in one search interface, which is useful for browsing, but the library you actually install into your project is still the individual source like Lucide or Material Design.

Library vs. set vs. collection

These three words get used interchangeably, so it helps to separate them:

Term What it is Typical use
Icon set A fixed group of icons in one style, often a one-time download A landing page needing 10 icons
Icon library A versioned package with a consistent style, installable and updatable An app with icons across dozens of components
Collection / aggregator A search layer over many libraries Finding the right icon before you commit

A library implies ongoing maintenance: new icons get added, naming stays stable, and you pull updates through a package manager. A set is frozen the moment you download it. An aggregator like IconShelf helps you compare across sources but doesn't replace the source library in your build.

How to compare the popular libraries

The four most common starting points differ mainly in style and weight:

  • Material Design Icons — Google's system, huge coverage, multiple weights (filled, outlined, rounded, sharp). Best when you're already in a Material UI or Android context.
  • Feather — minimal, consistent 24px stroke icons. Small set, very uniform, good for clean dashboards. Development has slowed, so treat it as stable rather than growing.
  • Heroicons — by the Tailwind team, offered in outline, solid, and mini sizes. Pairs naturally with Tailwind projects.
  • Lucide — a community fork and expansion of Feather with far more icons, still stroke-based and consistent. A common pick when Feather's coverage runs out.

Compare them on the same axes before deciding:

  1. Style — stroke vs. filled, and whether the library offers both.
  2. Coverage — does it have the niche icons your product needs (industry, actions, states)?
  3. Sizes/weights — can you get outline and solid from one source?
  4. License — most of these are open source (commonly MIT or similar), but verify the specific license before commercial use.
  5. Maintenance — recent releases and active issues signal a library that will keep working.

Check license, format, and consistency first

Before adopting anything, confirm three things:

  • License — read the actual license file. "Free" and "open source" are not the same as "public domain." IconShelf notes that all icons are property of their respective owners, so the aggregator is a discovery tool, not a license grant.
  • Format — SVG scales cleanly and can be recolored with CSS; PNG is raster and fixed-size. Prefer SVG for UI work and reserve PNG for cases where SVG isn't supported. (For a deeper look at when raster wins, see the PNG vs. SVG question.)
  • Consistency — mixing a stroke library with a filled one in the same toolbar looks broken. Pick one visual language per surface.

How to integrate a library

Three common paths, from most to least automated:

Package manager (recommended for apps). Install the library, import icons as components, and let your bundler tree-shake unused ones. Input: the package name. Action: import the specific icon. Result: only the icons you use ship in the build.

CDN or icon font. Link a stylesheet and reference icons by class name. Fast to set up, but you often load the whole set and lose per-icon tree-shaking. Fine for prototypes.

Copy-paste SVG. Grab the raw SVG from the library's site or an aggregator and paste it inline. Best for a few one-off icons; becomes unmanageable at scale because updates are manual.

A typical component-based flow looks like this:

npm install lucide-react

import { Search, Settings } from "lucide-react";

<Search size={20} />
<Settings size={20} />

The expected result is two icons rendered at 20px that inherit color from CSS, with no extra files to manage.

Common pitfalls

  • Mixing too many libraries. Every additional source adds a slightly different grid, stroke width, and corner radius. Two libraries is usually one too many on a single screen.
  • Ignoring the grid. Icons drawn on different pixel grids (16px vs. 24px) look misaligned even at the same rendered size.
  • Skipping the license check. A permissive-looking icon can carry attribution requirements. Confirm before shipping.
  • Hardcoding colors. Inline SVGs with baked-in fills can't adapt to dark mode. Use currentColor where the library supports it.
  • Treating an aggregator as the source. Searching 236 libraries on IconShelf is great for discovery, but install from the original library so you get versioning and updates.

A quick decision path

  1. Already using a design system (Material, Tailwind)? Start with its native library.
  2. Need a clean stroke style with broad coverage? Try Lucide; fall back to Feather for a smaller, frozen set.
  3. Need filled and outline from one source? Heroicons or Material.
  4. Only need a few icons and no updates? Download a set and paste the SVGs.
  5. Unsure what exists? Search an aggregator, then install the winning library directly.

The core rule: one library per visual surface, verified license, SVG by default, and install through a package manager so updates stay painless.