Fluent UI Icons and Boxicons are two of the most widely used open-source icon sets. Both are free, both ship framework packages, and both will look perfectly reasonable in a product UI — which is exactly why the choice is annoying. This page puts the two side by side using the actual artwork and the real numbers.
| Fluent UI Icons | Boxicons | |
|---|---|---|
| Icons | 20,170 | 3,389 |
| Visual variants per concept | 2 — regular and filled | 3 — regular, solid and logos |
| Design grid | 12–48 | 24×24 |
| License | MIT | MIT |
| Attribution required | No | No |
| Official React package | @fluentui/react-icons | boxicons |
Every pair below is the same concept rendered from each library's own source files. This is the part you cannot get from a written review — the difference in stroke weight, corner rounding and optical size is the thing you will actually notice in your interface.
Enterprise applications, Microsoft 365 integrations, and products that already follow Fluent or need extremely broad coverage. The count alone means you will rarely need to look elsewhere.
Consider otherwise if: The size is also a drawback — with 20,170 icons, maintaining visual consistency across a product takes more discipline. Lucide and Heroicons are far easier to keep coherent.
Websites and apps that need UI icons and brand logos from one package — particularly portfolios, link-in-bio pages, tech stack sections, and footers.
Consider otherwise if: For pure brand logos with a cleaner license, Simple Icons is CC0 and has 3,714 marks. For UI icons alone, Remix Icon and Tabler are more consistent.
Fluent UI Icons contains 20,170 icons and Boxicons contains 3,389. Fluent UI Icons is Microsoft's icon library for the Fluent Design System, and at 20,170 icons it is the largest set indexed on IconStash. The icons are drawn across multiple sizes from 12px to 48px and in Regular and Filled styles.
Boxicons is a long-running free icon pack by Atisa, with 3,389 icons across three families: Regular (outline), Solid (filled), and Logos. The logo set is a significant part of the appeal — hundreds of brand marks maintained alongside the UI icons.
Fluent UI Icons is released under MIT. Commercial use, modification and redistribution with no attribution required.
Boxicons is released under MIT. Commercial use, modification and redistribution with no attribution required.
You do not have to commit to one. IconStash indexes both libraries, so you can search a concept once and see how each set drew it, then export SVG or PNG at any size and colour. Start with Fluent UI Icons or Boxicons, or browse every library comparison.
Both have first-party React packages: @fluentui/react-icons and boxicons. Fluent UI has the larger catalogue, so for a React app the practical difference is coverage and visual style rather than integration effort. Both tree-shake, so bundle size tracks the number of icons you import, not the size of the library.
Fluent UI Icons has 20,170 icons and Boxicons has 3,389. Fluent UI Icons is larger by about 495%. Raw count is not the whole story though — a 20,000-icon set with many near-duplicate variants can be slower to search than a tightly edited 2,000-icon set.
You can, but it usually looks wrong. Each library draws to its own grid and stroke weight — Fluent UI uses 12–48 and Boxicons uses 24×24 — so icons from both sit slightly differently next to each other. If you must mix them, keep each library to a distinct area of the interface rather than interleaving them in the same toolbar.
Fluent UI Icons is MIT: Commercial use, modification and redistribution with no attribution required. Boxicons is MIT: Commercial use, modification and redistribution with no attribution required. Neither requires payment, but attribution rules differ, so check before shipping in a product where credit is inconvenient.
Fluent UI Icons offers regular and filled; Boxicons offers regular, solid and logos. If you need to express selected and unselected states with the same glyph, the library with more variants saves you from importing a second set.
At 16px, stroke weight and counter size matter more than coverage. Fluent UI draws on a 12–48 grid and Boxicons on 24×24. Libraries that redraw per size rather than scaling — such as Fluent UI — generally hold up best. The reliable test is to preview both at your actual render size, which you can do on any icon page on IconStash.