Fluent icons vs. Material Symbols vs. Heroicons vs. Lucide

Choosing an icon set early saves a lot of rework later. Changing icons halfway through a project means touching every screen. Here's how Microsoft's Fluent UI System Icons compare with three other widely used open-source sets. The numbers below are approximate and grow as the projects add icons.

At a glance

	Fluent UI System Icons	Material Symbols	Heroicons	Lucide
Maintained by	Microsoft	Google	Tailwind Labs	Open-source community
License	MIT	Apache 2.0	MIT	ISC
Size of set	Thousands of designs	Thousands of designs	A few hundred	Over a thousand
Styles	Regular, Filled (plus Color for some icons)	Outlined, Rounded, Sharp, each with a fill option	Outline, Solid, Mini, Micro	Outline
Sizes	Hand-tuned sizes, commonly 16–48 px	Variable font with an optical-size axis	24, 20 and 16 px	24 px, stroke adjustable
Official React package	Yes	Via community packages	Yes	Yes

Fluent UI System Icons

Strengths

• A very large, consistent set with good coverage of productivity concepts: documents, calendars, people, text formatting, devices and communication.
• Many icons are hand-tuned at several sizes, so small sizes look crisp instead of just being scaled down.
• Filled and regular versions share silhouettes, which makes on/off state toggles easy. See filled vs. regular icons.
• MIT License, and a well-maintained React package.

Trade-offs

• The look is distinctly Microsoft: soft corners and a friendly geometric style. That's great for tools and productivity apps, but may clash with a very sharp or playful brand.
• Not every icon exists at every size.

Best for: dashboards, productivity and business apps, anything that integrates with the Microsoft ecosystem, and apps that need a very wide range of concepts.

Material Symbols

Strengths

• Huge coverage, and the default choice for Android and Material Design apps.
• Delivered as a variable font, so you can adjust weight, fill and optical size continuously.
• Three distinct styles (Outlined, Rounded, Sharp) let you match different brand personalities.

Trade-offs

• The variable-font approach is powerful, but loading the full font can be heavy. Subsetting or using SVG exports is worth the effort.
• Apache 2.0 has slightly more formal notice requirements than MIT.

Best for: Android apps, Material Design products, and teams that want fine control through font variation axes.

Heroicons

Strengths

• Small, carefully curated and extremely consistent, made by the Tailwind CSS team.
• Excellent defaults for marketing sites and SaaS interfaces, and pairs naturally with Tailwind.
• Distinct outline, solid, mini and micro variants, each tuned for its size.

Trade-offs

• A few hundred icons means you'll hit gaps in specialized apps, such as editors or admin tools with many actions.

Best for: landing pages, SaaS products and Tailwind projects with a focused feature set.

Lucide

Strengths

• A community-driven continuation of Feather Icons, with a large and growing set.
• Stroke-based, so you can change stroke width globally for a lighter or bolder feel.
• Official packages for many frameworks.

Trade-offs

• Outline style only. There's no built-in filled variant for state toggles.
• Community-maintained, so style consistency depends on contributor review, although it's generally very good.

Best for: developers who want a clean, neutral outline style with framework packages everywhere.

How to choose

1. Match your platform. Building for Windows or around Microsoft 365? Fluent will feel native. Android? Material Symbols.
2. List the concepts you need. Write down 30–40 icons your product needs and check each set. Coverage gaps show up fast.
3. Decide whether you need filled states. If toggles and selected states matter, Fluent's filled/regular pairs or Heroicons' outline/solid pairs make them straightforward.
4. Check the license fits your distribution. All four are permissive, but know what notice you need to include. See our Fluent license guide.
5. Don't mix sets casually. Different sets use different stroke weights, corner radii and optical sizes. If you must fill a gap, redraw the missing icon in the style of your main set.

If Fluent looks like the right fit, search the full set or browse it A–Z.