diff --git a/.changeset/nasty-spies-repair.md b/.changeset/nasty-spies-repair.md
new file mode 100644
index 0000000..0aba6bd
--- /dev/null
+++ b/.changeset/nasty-spies-repair.md
@@ -0,0 +1,5 @@
+---
+"@urami/core": minor
+---
+
+added `defaultDomain` config as a way to define domain to fetch an image as a relative path
diff --git a/apps/docs/src/core/configuration.md b/apps/docs/src/core/configuration.md
index 8bdc7e5..05f803e 100644
--- a/apps/docs/src/core/configuration.md
+++ b/apps/docs/src/core/configuration.md
@@ -50,6 +50,12 @@ List of domains that allowed to use the API, this will be checked via header `Re
 
 Only applied when `process.env.NODE_ENV` is set to `production`. Unset this option will allow anywhere to request image from this API.
 
+## defaultDomain
+
+`string | undefined`
+
+Default domain to use when domain is not specified in URL. Defaults to undefined
+
 ## ttl
 
 `number`
diff --git a/packages/core/src/@types/Config.ts b/packages/core/src/@types/Config.ts
index 896a9d2..4e9fa14 100644
--- a/packages/core/src/@types/Config.ts
+++ b/packages/core/src/@types/Config.ts
@@ -5,6 +5,9 @@ export interface Config {
   // lists of allowed domain to use this API (will check via header `Referer`), not specifying anything will allow all domains to use this API
   allowedDomains?: string[]
 
+  // default domain to use if no domain is specified
+  defaultDomain?: string
+
   // directory to temporary store optimized images (default to .svelte-kit/images), paths will be relative to process.cwd()
   storePath: string
 
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 5612713..c7da350 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -42,18 +42,18 @@ export const createRequestHandler =
     const width = Number(fullRequestUrl.searchParams.get('w') ?? '')
     const quality = Number(fullRequestUrl.searchParams.get('q') ?? '')
 
+    // Check if the URL is valid. If not, try to construct a new URL using defaultDomain or referer header.
     try {
       // attempt to construct a URL, a relative URL will throw an error
       url = new URL(url).toString()
     } catch (e) {
-      // if relative URL does not have a referer header, throw an error
-      const referer = request.headers.get('referer')
-      if (referer === null) {
-        throw error(400, 'missing url')
-      }
+      // if default domain is specified, construct a new URL using the default domain
+      const targetDomain =
+        mergedConfig.defaultDomain ?? request.headers.get('referer')
+
+      if (targetDomain === null) throw error(400, 'missing url')
 
-      // construct a new URL using the referer header
-      url = new URL(url, referer).toString()
+      url = new URL(url, mergedConfig.defaultDomain).toString()
     }
 
     // make sure that this url is allowed to optimize