diff --git a/.changeset/flat-wombats-sneeze.md b/.changeset/flat-wombats-sneeze.md
new file mode 100644
index 000000000000..5141bd580c62
--- /dev/null
+++ b/.changeset/flat-wombats-sneeze.md
@@ -0,0 +1,5 @@
+---
+"wrangler": patch
+---
+
+Adds the Content-Type header when serving assets with `wrangler pages dev`. It guesses the mime-type based on the asset's file extension.
diff --git a/package-lock.json b/package-lock.json
index b2a0aa7e55e3..0d5a274d01ad 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13452,7 +13452,7 @@
       "license": "ISC"
     },
     "packages/wrangler": {
-      "version": "0.0.5",
+      "version": "0.0.6",
       "license": "MIT OR Apache-2.0",
       "dependencies": {
         "@cloudflare/pages-functions-compiler": "0.3.8",
@@ -13466,6 +13466,7 @@
       },
       "devDependencies": {
         "@iarna/toml": "^2.2.5",
+        "@types/mime": "^2.0.3",
         "@types/react": "^17.0.37",
         "@types/serve-static": "^1.13.10",
         "@types/signal-exit": "^3.0.1",
@@ -13483,6 +13484,7 @@
         "ink-select-input": "^4.2.1",
         "ink-table": "^3.0.0",
         "ink-text-input": "^4.0.2",
+        "mime": "^3.0.0",
         "node-fetch": "^3.1.0",
         "open": "^8.4.0",
         "path-to-regexp": "^6.2.0",
@@ -13502,6 +13504,12 @@
         "fsevents": "~2.3.2"
       }
     },
+    "packages/wrangler/node_modules/@types/mime": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/@types/mime/-/mime-2.0.3.tgz",
+      "integrity": "sha512-Jus9s4CDbqwocc5pOAnh8ShfrnMcPHuJYzVcSUU7lrh8Ni5HuIqX3oilL86p3dlTrk0LzHRCgA/GQ7uNCw6l2Q==",
+      "dev": true
+    },
     "packages/wrangler/node_modules/@types/yargs": {
       "version": "17.0.7",
       "integrity": "sha512-OvLKmpKdea1aWtqHv9bxVVcMoT6syAeK+198dfETIFkAevYRGwqh4H+KFxfjUETZuUuE5sQCAFwdOdoHUdo8eg==",
@@ -13551,6 +13559,18 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "packages/wrangler/node_modules/mime": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/mime/-/mime-3.0.0.tgz",
+      "integrity": "sha512-jSCU7/VB1loIWBZe14aEYHU/+1UMEHoaO7qxCOVJOw9GgH72VAWppxNcjU+x9a2k3GSIBXNKxXQFqRvvZ7vr3A==",
+      "dev": true,
+      "bin": {
+        "mime": "cli.js"
+      },
+      "engines": {
+        "node": ">=10.0.0"
+      }
+    },
     "packages/wrangler/node_modules/mimic-fn": {
       "version": "4.0.0",
       "integrity": "sha512-vqiC06CuhBTUdZH+RYl8sFrL096vA45Ok5ISO6sE/Mr1jRbGH4Csnhi8f3wKVl7x8mO4Au7Ir9D3Oyv1VYMFJw==",
@@ -23249,6 +23269,7 @@
       "requires": {
         "@cloudflare/pages-functions-compiler": "0.3.8",
         "@iarna/toml": "^2.2.5",
+        "@types/mime": "^2.0.3",
         "@types/react": "^17.0.37",
         "@types/serve-static": "^1.13.10",
         "@types/signal-exit": "^3.0.1",
@@ -23268,6 +23289,7 @@
         "ink-select-input": "^4.2.1",
         "ink-table": "^3.0.0",
         "ink-text-input": "^4.0.2",
+        "mime": "^3.0.0",
         "miniflare": "2.0.0-rc.4",
         "node-fetch": "^3.1.0",
         "open": "^8.4.0",
@@ -23283,6 +23305,12 @@
         "yargs": "^17.3.0"
       },
       "dependencies": {
+        "@types/mime": {
+          "version": "2.0.3",
+          "resolved": "https://registry.npmjs.org/@types/mime/-/mime-2.0.3.tgz",
+          "integrity": "sha512-Jus9s4CDbqwocc5pOAnh8ShfrnMcPHuJYzVcSUU7lrh8Ni5HuIqX3oilL86p3dlTrk0LzHRCgA/GQ7uNCw6l2Q==",
+          "dev": true
+        },
         "@types/yargs": {
           "version": "17.0.7",
           "integrity": "sha512-OvLKmpKdea1aWtqHv9bxVVcMoT6syAeK+198dfETIFkAevYRGwqh4H+KFxfjUETZuUuE5sQCAFwdOdoHUdo8eg==",
@@ -23317,6 +23345,12 @@
           "integrity": "sha512-LnQR4bZ9IADDRSkvpqMGvt/tEJWclzklNgSw48V5EAaAeDd6qGvN8ei6k5p0tvxSR171VmGyHuTiAOfxAbr8kA==",
           "dev": true
         },
+        "mime": {
+          "version": "3.0.0",
+          "resolved": "https://registry.npmjs.org/mime/-/mime-3.0.0.tgz",
+          "integrity": "sha512-jSCU7/VB1loIWBZe14aEYHU/+1UMEHoaO7qxCOVJOw9GgH72VAWppxNcjU+x9a2k3GSIBXNKxXQFqRvvZ7vr3A==",
+          "dev": true
+        },
         "mimic-fn": {
           "version": "4.0.0",
           "integrity": "sha512-vqiC06CuhBTUdZH+RYl8sFrL096vA45Ok5ISO6sE/Mr1jRbGH4Csnhi8f3wKVl7x8mO4Au7Ir9D3Oyv1VYMFJw==",
diff --git a/packages/wrangler/package.json b/packages/wrangler/package.json
index 103ca9bc8e80..4ddb93dc44de 100644
--- a/packages/wrangler/package.json
+++ b/packages/wrangler/package.json
@@ -46,6 +46,7 @@
   },
   "devDependencies": {
     "@iarna/toml": "^2.2.5",
+    "@types/mime": "^2.0.3",
     "@types/react": "^17.0.37",
     "@types/serve-static": "^1.13.10",
     "@types/signal-exit": "^3.0.1",
@@ -63,6 +64,7 @@
     "ink-select-input": "^4.2.1",
     "ink-table": "^3.0.0",
     "ink-text-input": "^4.0.2",
+    "mime": "^3.0.0",
     "node-fetch": "^3.1.0",
     "open": "^8.4.0",
     "path-to-regexp": "^6.2.0",
diff --git a/packages/wrangler/src/pages.tsx b/packages/wrangler/src/pages.tsx
index 4b36d97dd2e5..9385865fcf0c 100644
--- a/packages/wrangler/src/pages.tsx
+++ b/packages/wrangler/src/pages.tsx
@@ -6,6 +6,7 @@ import { execSync, spawn } from "child_process";
 import { Headers, Request, Response } from "undici";
 import type { MiniflareOptions } from "miniflare";
 import type { RequestInfo, RequestInit } from "undici";
+import { getType } from "mime";
 import open from "open";
 import { watch } from "chokidar";
 
@@ -466,12 +467,20 @@ const generateAssetsFetch = async (
         if ((asset = getAsset(`${cwd}/404.html`))) {
           deconstructedResponse.status = 404;
           deconstructedResponse.body = serveAsset(asset);
+          deconstructedResponse.headers.set(
+            "Content-Type",
+            getType(asset) || "application/octet-stream"
+          );
           return deconstructedResponse;
         }
       }
 
       if ((asset = getAsset(`/index.html`))) {
         deconstructedResponse.body = serveAsset(asset);
+        deconstructedResponse.headers.set(
+          "Content-Type",
+          getType(asset) || "application/octet-stream"
+        );
         return deconstructedResponse;
       }
 
@@ -484,6 +493,10 @@ const generateAssetsFetch = async (
     if (url.pathname.endsWith("/")) {
       if ((asset = getAsset(`${url.pathname}/index.html`))) {
         deconstructedResponse.body = serveAsset(asset);
+        deconstructedResponse.headers.set(
+          "Content-Type",
+          getType(asset) || "application/octet-stream"
+        );
         return deconstructedResponse;
       } else if (
         (asset = getAsset(`${url.pathname.replace(/\/$/, ".html")}`))
@@ -511,6 +524,10 @@ const generateAssetsFetch = async (
         const extensionlessPath = url.pathname.slice(0, -".html".length);
         if (getAsset(extensionlessPath) || extensionlessPath === "/") {
           deconstructedResponse.body = serveAsset(asset);
+          deconstructedResponse.headers.set(
+            "Content-Type",
+            getType(asset) || "application/octet-stream"
+          );
           return deconstructedResponse;
         } else {
           deconstructedResponse.status = 301;
@@ -522,6 +539,10 @@ const generateAssetsFetch = async (
         }
       } else {
         deconstructedResponse.body = serveAsset(asset);
+        deconstructedResponse.headers.set(
+          "Content-Type",
+          getType(asset) || "application/octet-stream"
+        );
         return deconstructedResponse;
       }
     } else if (hasFileExtension(url.pathname)) {
@@ -531,6 +552,10 @@ const generateAssetsFetch = async (
 
     if ((asset = getAsset(`${url.pathname}.html`))) {
       deconstructedResponse.body = serveAsset(asset);
+      deconstructedResponse.headers.set(
+        "Content-Type",
+        getType(asset) || "application/octet-stream"
+      );
       return deconstructedResponse;
     }