diff --git a/src/utils/lang/html.ts b/src/utils/lang/html.ts
index 8a897b2..1fe3d40 100644
--- a/src/utils/lang/html.ts
+++ b/src/utils/lang/html.ts
@@ -4,6 +4,53 @@ export function isHTML(maybeHTML: string): boolean {
   return [...$div.childNodes].reverse().some(($child) => $child.nodeType === 1)
 }
 
+function getFetchResolverScript() {
+  return `<script data-static-preview-fetch-resolver>
+;(() => {
+  const proxyPrefix = 'https://api.codetabs.com/v1/proxy/?quest='
+  const nativeFetch = window.fetch.bind(window)
+
+  const shouldProxy = (url) => {
+    if (url.protocol !== 'http:' && url.protocol !== 'https:') {
+      return false
+    }
+
+    if (url.href.startsWith(proxyPrefix)) {
+      return false
+    }
+
+    const baseUrl = new URL(document.baseURI)
+    return url.origin === baseUrl.origin
+  }
+
+  window.fetch = (input, init) => {
+    try {
+      const requestUrl =
+        typeof input === 'string'
+          ? input
+          : input instanceof URL
+            ? input.href
+            : input.url
+
+      const absoluteUrl = new URL(requestUrl, document.baseURI)
+
+      if (shouldProxy(absoluteUrl)) {
+        const proxiedUrl = \`\${proxyPrefix}\${encodeURIComponent(absoluteUrl.href)}\`
+
+        if (typeof input !== 'string' && !(input instanceof URL)) {
+          return nativeFetch(new Request(proxiedUrl, input), init)
+        }
+
+        return nativeFetch(proxiedUrl, init)
+      }
+    } catch {}
+
+    return nativeFetch(input, init)
+  }
+})()
+</script>`
+}
+
 function getTitle(html: string) {
   // TODO: Regex might reasonably be faster here
   const $div = document.createElement('div')
@@ -24,7 +71,10 @@ export interface HTMLPageData {
 export function processHTML(html: string, url: string): HTMLPageData {
   const processedHTML = html
     // Add base tag to iframe
-    .replace(/<head([^>]*)>/i, `<head$1><base href="${url}">`)
+    .replace(
+      /<head([^>]*)>/i,
+      `<head$1><base href="${url}">${getFetchResolverScript()}`,
+    )
     // Replace absolute paths with relative paths
     .replace(/((src|href|content)=")\/(.*?")/gm, '$1$3')
 
diff --git a/tests/html.test.ts b/tests/html.test.ts
new file mode 100644
index 0000000..53cb387
--- /dev/null
+++ b/tests/html.test.ts
@@ -0,0 +1,50 @@
+import { processHTML } from '../src/utils/lang/html'
+
+const HTML_URL =
+  'https://gitlab.com/sirajchokshi/static-preview-test/-/raw/main/wasm.html'
+
+describe('[HTML] processHTML', () => {
+  it('injects base url and runtime fetch resolver', () => {
+    const html = `
+      <!DOCTYPE html>
+      <html>
+        <head>
+          <title>WASM | Static Preview Test</title>
+        </head>
+        <body>
+          <script src="/assets/wasm.js"></script>
+        </body>
+      </html>
+    `
+
+    const { processedHTML, title } = processHTML(html, HTML_URL)
+
+    expect(processedHTML).toContain(`<base href="${HTML_URL}">`)
+    expect(processedHTML).toContain('data-static-preview-fetch-resolver')
+    expect(processedHTML).toContain('window.fetch = (input, init) =>')
+    expect(title).toEqual('WASM | Static Preview Test')
+  })
+
+  it('rewrites leading slash paths to document-relative paths', () => {
+    const html = `
+      <!DOCTYPE html>
+      <html>
+        <head>
+          <link rel="stylesheet" href="/assets/main.css" />
+          <meta content="/assets/preview.png" />
+        </head>
+        <body>
+          <a href="/index.html">Home</a>
+          <script src="/assets/wasm.js"></script>
+        </body>
+      </html>
+    `
+
+    const { processedHTML } = processHTML(html, HTML_URL)
+
+    expect(processedHTML).toContain('href="assets/main.css"')
+    expect(processedHTML).toContain('content="assets/preview.png"')
+    expect(processedHTML).toContain('href="index.html"')
+    expect(processedHTML).toContain('src="assets/wasm.js"')
+  })
+})
