Open Source Icon REST API

Search, fetch and render icons over HTTP.

Two endpoints: search 314,000+ open-source icons, then render any of them as SVG. Search takes the free license key from your Settings; the SVG itself needs nothing at all.

Icon search needs a license key. Every account has one, free: copy it in Settings and send it as Authorization: Bearer osi_…. A request with no header answers 401 {"error":"license_key_required"}, one with a key we do not know 401 {"error":"invalid_license_key"}. Keyed answers are Cache-Control: private, so store them in your own app rather than in a shared cache. Retrieving the SVG itself needs no key.

Our own VS Code extension, Figma plugin and MCP server search and insert icons through these two endpoints — they bundle no icon data at all — and they are open to you on the same terms. Access-Control-Allow-Origin: * on every response, so calls work from a browser, a null-origin plugin iframe or a server, and preflights allow Authorization.

Fair use. Cache responses on your side; bulk downloads should use the Iconify JSON packages instead. Icons keep their own open-source licenses — see the library pages for each one.

Search icons

GET/api/search?q={query}&lib={prefixes}&col={slugs}&page={1-20}&per_page={1-100}

The same search the website runs: typo-tolerant, ranked by library popularity, filtered by library and collection. Each hit carries palette, which is true for multicolor sets — their icons ignore the color parameter.

Parameter	Accepts
q	The query, 2 to 120 characters — or * to list a whole library or collection, which is only accepted together with lib or col.
lib	Comma-separated library prefixes, up to 50: lib=lucide,tabler. Results then come from those libraries only.
col	Comma-separated collection slugs, up to 15: col=line-art-stroke. A library's prefix is in its page address (/libraries/lucide) and a collection's slug in its own (/collections/line-art-stroke).
page	1 to 20, default 1.
per_page	1 to 100, default 60.

curl

curl -H "Authorization: Bearer osi_…" \
  "https://opensourceicon.com/api/search?q=arrow&per_page=2"

fetch

// one library at a time; ?q=*&lib=lucide lists the whole library
const res = await fetch(
  "https://opensourceicon.com/api/search?q=arrow&lib=lucide&per_page=20",
  { headers: { Authorization: `Bearer ${licenseKey}` } },
);
const { hits, found } = await res.json();

Response

{
  "hits": [
    { "prefix": "glyphs", "name": "arrow", "palette": false },
    { "prefix": "uil", "name": "arrow", "palette": false }
  ],
  "found": 9625,
  "page": 1,
  "per_page": 2
}

Content-Type: application/json
Authorization: Authorization: Bearer osi_…
Cache-Control: private, max-age=3600
Errors: 401 without a key or with an unknown one. 400 {"error":"too_short"} for a query under two characters, and for a bare * with no lib or col; 400 {"error":"invalid_filters"} for a lib or col we cannot parse. If the search engine is briefly unavailable a name-index fallback answers in the same shape instead of an error, and found is then a floor rather than an exact total.

One icon as SVG

GET/api/icon/{prefix}/{name}?size={px}&color={css color}

The rendered SVG itself, served with a content security policy that forbids scripts and external resources.

Parameter	Accepts
size	Sets width and height in pixels. Capped at 2048.
color	Applied to monotone sets only. A hex value, a CSS colour keyword, or rgb(), rgba(), hsl() or hsla() notation. Anything else returns 400.

curl

curl "https://opensourceicon.com/api/icon/lucide/house?size=48&color=%23ff0000"

fetch

const res = await fetch("https://opensourceicon.com/api/icon/lucide/house?size=48");
const svg = await res.text();

Response

<svg xmlns="http://www.w3.org/2000/svg" width="48" height="48"
     viewBox="0 0 24 24"><path fill="none" stroke="#ff0000" .../></svg>

Content-Type: image/svg+xml
Authorization: None — this one stays open.
Cache-Control: public, max-age=86400, s-maxage=604800, stale-while-revalidate=604800
Errors: 404 for an unknown icon, 400 for a colour outside the allowed forms.