API docs

Icon Horse returns the logo or favicon for any website or product. Give it a domain (stripe.com) or a product name (Microsoft Entra ID) and get back a PNG, WebP, ICO or SVG. Free, no API key, no signup. Every URL below works in an <img> tag, a spreadsheet, a slide or a script.

Machine-readable: openapi.json · llms.txt · llms-full.txt (this page as markdown)

1. Quick start

<img src="https://icon.horse/icon/stripe.com" alt="Stripe" width="32" height="32">

That is the whole integration. The URL returns Stripe's icon as a PNG, up to 256×256. If the site has no icon, you get a letter tile instead of a broken image (or a 404, if you ask for one).

curl -o stripe.png https://icon.horse/icon/stripe.com/128
curl -o entra.png  https://icon.horse/name/microsoft-entra-id/128
curl 'https://icon.horse/api/icons?q=stripe.com&q=Microsoft%20Entra%20ID'

2. Icon by domain: `/icon/<domain>`

URL	Returns
`/icon/github.com`	PNG, the best icon the site has, up to 256px
`/icon/github.com/64`	PNG at 16, 32, 48, 64, 128 or 256px
`/icon/github.com/256/webp`	WebP at any allowed size
`/icon/github.com/ico`	ICO with 16, 32 and 48px frames
`/icon/github.com/svg`	The site's own SVG, or 404 if it has none

Sizes: 16, 32, 48, 64, 128, 256. Formats: png (default), webp, ico, svg. ICO and SVG take no size. ?size=64 and ?format=webp also work and redirect (301) to the path form.

Paste anything. Scheme, www., path, port and case are dropped, and the request redirects (301) to one canonical URL:

/icon/https://www.Stripe.com/pricing   →  301  /icon/stripe.com
/icon/stripe.com?size=64&format=webp   →  301  /icon/stripe.com/64/webp

Icon Horse ranks the site's <link rel="icon"> tags, apple-touch-icon, web app manifest icons and /favicon.ico. SVG wins, then the largest size. Parked "domain for sale" pages count as not found.

3. Icon by product name: `/name/<product>`

Many products do not have their own domain. Microsoft Entra ID lives on microsoft.com; CoCounsel lives on thomsonreuters.com. Ask for them by name:

https://icon.horse/name/microsoft-entra-id
https://icon.horse/name/microsoft-entra-id/128/webp
https://icon.horse/icon?q=Microsoft%20Entra%20ID     →  301  /name/microsoft-entra-id

The name becomes a lowercase slug. Sizes, formats and variants work the same as /icon. Names resolve in this order:

Curated catalog. Hand-checked name → domain or image entries for products that public data gets wrong.
Wikidata. The query must match whole words in an entity's label or alias, and the entity must have an icon, a logo or an official website. Icon Horse tries the icon, then a square logo, then the website's favicon, then a wide wordmark.

No match means not found. Icon Horse never guesses a logo for a name it does not know.

4. Variants: trim, weight, pad, bg, tone, fallback

Query options that make a row of logos look even. They work on /icon and /name, at every size and raster format.

Option	Effect
`trim=1`	Cut empty border so the mark fills the frame
`weight=1`	Scale by visual mass, not bounding box, so a solid square and a thin mark look equally heavy. Implies `trim`
`pad=0..40`	Padding, percent of each side
`bg=white`, `bg=black`, `bg=<hex>`	Background color. Default is transparent. Hex without `#`, 3 or 6 digits. With `bg` set, a logo that will not read on it gets an `X-Icon-Warning` header
`tone=mono`, `color=<hex>`	Recolor the mark to one color to match a deck. Default color is black or white, whichever reads on `bg`
`fallback=404`	Return 404 instead of a letter tile when no icon is found

https://icon.horse/icon/bill.com/128?trim=1&weight=1&pad=8&bg=white
https://icon.horse/icon/stripe.com/64?bg=0a2540
https://icon.horse/icon/example.com?fallback=404

Use fallback=404 with the onerror handler of an <img> when you would rather hide a missing logo than show a letter.

5. Honest response headers

Every image response says what it is. Browsers can read these cross-origin (Access-Control-Expose-Headers is set).

Header	Meaning
`X-Icon-Fallback`	`true` when the image is a placeholder letter tile
`X-Icon-Source-Size`	Original size, such as `48x48`, or `vector`. Under 128px looks soft when scaled up
`X-Icon-Source`	The URL the icon came from
`X-Icon-Confidence`	0 to 1. `0` means placeholder
`X-Icon-Stand-In`	`true` when a styled request (`weight`, `pad`, `bg` or `tone`) got a neutral stand-in tile because no logo exists
`X-Icon-Warning`	Problems with a styled icon: low contrast on `bg`, or `tone=mono` skipped

$ curl -sI https://icon.horse/icon/stripe.com/64
HTTP/2 200
content-type: image/png
x-icon-fallback: false
x-icon-source-size: vector
x-icon-confidence: 0.9
x-icon-source: https://images.stripeassets.com/.../favicon.svg

const res = await fetch('https://icon.horse/icon/acme.example')
if (res.headers.get('X-Icon-Fallback') === 'true') {
  // No real logo. Show a placeholder of your own, or nothing.
}

6. Icon pages: `/site/<domain>`

A page for people: the icon, the site's name and description, downloads in every size and format, and copy-paste embed code.

https://icon.horse/site/stripe.com

Downloads: PNG at 16 to 256px, WebP 256px, ICO, and SVG when the site has one.

7. Batch JSON: `/api/icons`

Resolve up to 20 domains or product names in one call. Each result says whether a real icon was found, how confident the match is, where it came from, and the URLs to use.

curl 'https://icon.horse/api/icons?q=stripe.com&q=Microsoft%20Entra%20ID'

curl -X POST https://icon.horse/api/icons \
  -H 'Content-Type: application/json' \
  -d '{"q": ["stripe.com", "Microsoft Entra ID", "CoCounsel"]}'

A query with a space, or with no dot, is a product name. Anything else is a domain. Response (shortened):

{
  "results": [
    {
      "query": "Microsoft Entra ID",
      "kind": "name",
      "found": true,
      "fallback": false,
      "confidence": 0.85,
      "name": "Microsoft Entra ID",
      "hostname": "azure.microsoft.com",
      "via": "wikidata-logo",
      "source": { "url": "https://commons.wikimedia.org/wiki/Special:FilePath/Microsoft%20Entra%20ID%20color%20icon.svg", "format": "svg", "size": "vector" },
      "urls": {
        "png": "https://icon.horse/name/microsoft-entra-id",
        "png_64": "https://icon.horse/name/microsoft-entra-id/64",
        "webp": "https://icon.horse/name/microsoft-entra-id/256/webp",
        "ico": "https://icon.horse/name/microsoft-entra-id/ico",
        "svg": "https://icon.horse/name/microsoft-entra-id/svg",
        "page": null
      },
      "candidates": [ ... ]
    }
  ]
}

Field	Meaning
`kind`	`domain` or `name`
`found` / `fallback`	Whether a real icon exists. When `found` is false, `urls` is null
`confidence`	0 to 1, same as `X-Icon-Confidence`
`via`	How the icon was found: `website`, `catalog`, or a Wikidata source such as `wikidata-logo`
`source`	Original URL, format and size (`vector` for SVG)
`urls`	Ready-to-use links. `svg` is null when there is no vector; `page` is null for names
`candidates`	Other sources considered, for name lookups
`error`	Set instead of the fields above when a query is empty or the host is rejected

GET responses are cached for 5 minutes. POST is not cached. More than 20 queries returns 400.

8. Force a refresh: `/refresh/<domain>`

Changed your favicon? Refetch it now:

curl https://icon.horse/refresh/example.com
{"refreshed":true,"changed":true,"purged":true}

Without a refresh, a changed icon shows up within about 2 days on its own.

9. Use in Google Slides, Docs or PowerPoint

Slides and documents accept an image by URL. Use a PNG URL; they do not accept SVG or ICO.

Google Slides or Google Docs: Insert → Image → By URL. Paste https://icon.horse/icon/stripe.com/256.
PowerPoint or Word on Windows: Insert → Pictures → This Device, then paste the same URL into the file name box. On Mac or the web, open the URL in a browser, save the PNG, and insert the file.
Product without a domain: use the name form, such as https://icon.horse/name/microsoft-entra-id/256.

Tip for an even row of logos: add ?trim=1&weight=1&pad=8&bg=white. Every logo then fills its square the same way on a white tile, so a row of customer or vendor logos lines up.

https://icon.horse/icon/stripe.com/256?trim=1&weight=1&pad=8&bg=white
https://icon.horse/icon/github.com/256?trim=1&weight=1&pad=8&bg=white
https://icon.horse/name/microsoft-entra-id/256?trim=1&weight=1&pad=8&bg=white

Google Sheets works too: =IMAGE("https://icon.horse/icon/stripe.com/64").

10. For AI agents: MCP, stack and logo sets

Agents can call the plain URLs and /api/icons above. Three more endpoints are built for agent workflows; openapi.json has every parameter.

MCP server: `/mcp`

A remote Model Context Protocol server at https://icon.horse/mcp (Streamable HTTP, no key) with four tools:

find_logos: logos for a list of domains or product names, with confidence and fallback flags.
get_logo_image: one logo returned as an image, so the agent can look at it before placing it.
logo_set: a matched set of logos for one background color and size, with contrast warnings.
company_stack: which tools a company uses, with evidence.

claude mcp add --transport http icon-horse https://icon.horse/mcp

Company stack: `/api/stack`

Which tools a company uses: client portals, practice software, email, CRM, analytics. It reads the homepage, a few likely pages (client portal, pay, contact) and DNS records. Every tool comes with the evidence that put it there (a link and its text, a script, an MX or TXT record) and a confidence. No observed signal, no tool. A missing tool means no evidence was found, not that the company does not use it.

curl 'https://icon.horse/api/stack?domain=stripe.com'

Logo set: `/api/set`

A row of logos with the same size, visual weight, padding, background and tone. Parameters: q (repeat, up to 20), size, bg, pad, tone (color or mono), color, gap. Each result adds set_url (the styled image), warnings (for example low contrast on a dark row) and standIn (true when no real logo exists and a neutral tile stands in). row_url renders the whole row as one PNG.

curl 'https://icon.horse/api/set?q=stripe.com&q=Microsoft%20Teams&size=128&bg=ffffff&pad=8'
curl -X POST https://icon.horse/api/set -d '{"q": ["stripe.com", "Microsoft Teams"], "bg": "1f2937", "tone": "mono"}'

11. Caching and limits

No API key. CORS is open (Access-Control-Allow-Origin: *).
Icons are cached at the edge for 1 day and refreshed in the background. Letter tiles are cached for 5 minutes, so a site that adds an icon shows up fast.
Requests that reach the origin are rate-limited per IP: about 60 per minute for icons and pages, 20 per minute for /api/icons, 5 per minute for /refresh. Edge cache hits do not count. Over the limit returns 429.
Errors are plain text with a 400: invalid size: must be one of 16, 32, 48, 64, 128, 256.

Need more volume or something custom? [email protected]

API docs

1. Quick start

2. Icon by domain: /icon/<domain>

3. Icon by product name: /name/<product>

4. Variants: trim, weight, pad, bg, tone, fallback

5. Honest response headers

6. Icon pages: /site/<domain>

7. Batch JSON: /api/icons

8. Force a refresh: /refresh/<domain>