Icons8
~1.3M icons in 47 styles, free only under CC BY-ND with a mandatory backlink
Icons8 is a very large asset marketplace covering icons (roughly 1.3 million, drawn in 47 matched UI styles), plus stock photos, vector illustrations, music and AI tools such as an upscaler and background remover. Free downloads are permitted commercially but only under a Creative Commons Attribution-NoDerivs 3.0 licence that requires a visible link back to icons8.com and forbids modifying the artwork; paid plans remove both constraints. There is a documented REST API at developers.icons8.com, and the company also makes the Lunacy design tool.
Two hard blockers: icons8.com sits behind a Cloudflare interstitial that returns 403 to every automated fetch, and the free licence is Attribution-NoDerivs, so you may not recolour or edit an icon and you must render a visible credit link. Do not silently drop Icons8 assets into a product build; if the user has a paid plan, use the developers.icons8.com API instead of the site, and note its terms forbid caching responses. For anything an agent needs to fetch, restyle, or ship without attribution, Iconoir, Lucide or Phosphor are the correct choices.
Why it is here. The biggest icon catalogue on the web, and the clearest case where scale does not translate into usability for an automated workflow.
- ~1.3M icons in 47 matched styles
- free tier is CC BY-ND with mandatory backlink
- Cloudflare-blocked to automated fetching
- metered REST API that forbids caching
- also ships the Lunacy design app
Verified 2026-08-16. HTTP 403. https://icons8.com (403 Cloudflare challenge on two attempts via WebFetch and curl), https://icons8.com/license (403), https://developers.icons8.com/pricing (fetched OK), web search for icon count and licence terms
