diff --git a/.changeset/tricky-seahorses-look.md b/.changeset/tricky-seahorses-look.md
new file mode 100644
index 00000000000..a1b31c63614
--- /dev/null
+++ b/.changeset/tricky-seahorses-look.md
@@ -0,0 +1,8 @@
+---
+'firebase': minor
+'@firebase/storage': minor
+'@firebase/storage-types': minor
+---
+
+Add `storage().useEmulator()` method to enable emulator mode for storage, allowing users
+to set a storage emulator host and port.
diff --git a/common/api-review/storage.api.md b/common/api-review/storage.api.md
index 988b0fcc493..83939704281 100644
--- a/common/api-review/storage.api.md
+++ b/common/api-review/storage.api.md
@@ -61,7 +61,7 @@ export function getDownloadURL(ref: StorageReference): Promise<string>;
 export function getMetadata(ref: StorageReference): Promise<FullMetadata>;
 
 // @public
-export function getStorage(app: FirebaseApp, bucketUrl?: string): StorageService;
+export function getStorage(app?: FirebaseApp, bucketUrl?: string): StorageService;
 
 // @public
 export function list(ref: StorageReference, options?: ListOptions): Promise<ListResult>;
@@ -94,9 +94,9 @@ export class _Location {
     // (undocumented)
     get isRoot(): boolean;
     // (undocumented)
-    static makeFromBucketSpec(bucketString: string): _Location;
+    static makeFromBucketSpec(bucketString: string, host: string): _Location;
     // (undocumented)
-    static makeFromUrl(url: string): _Location;
+    static makeFromUrl(url: string, host: string): _Location;
     // (undocumented)
     get path(): string;
     }
@@ -253,6 +253,9 @@ export interface UploadTaskSnapshot {
     totalBytes: number;
 }
 
+// @public
+export function useStorageEmulator(storage: StorageService, host: string, port: number): void;
+
 
 // (No @packageDocumentation comment for this package)
 
diff --git a/packages/firebase/index.d.ts b/packages/firebase/index.d.ts
index d33bd26541b..b44df74f9b0 100644
--- a/packages/firebase/index.d.ts
+++ b/packages/firebase/index.d.ts
@@ -7612,6 +7612,13 @@ declare namespace firebase.storage {
      * @see {@link firebase.storage.Storage.maxUploadRetryTime}
      */
     setMaxUploadRetryTime(time: number): any;
+    /**
+     * Modify this `Storage` instance to communicate with the Cloud Storage emulator.
+     *
+     * @param host - The emulator host (ex: localhost)
+     * @param port - The emulator port (ex: 5001)
+     */
+    useEmulator(host: string, port: string): void;
   }
 
   /**
diff --git a/packages/storage-types/index.d.ts b/packages/storage-types/index.d.ts
index 5bd2b98dc05..735d8c32278 100644
--- a/packages/storage-types/index.d.ts
+++ b/packages/storage-types/index.d.ts
@@ -135,6 +135,7 @@ export class FirebaseStorage {
   refFromURL(url: string): Reference;
   setMaxOperationRetryTime(time: number): void;
   setMaxUploadRetryTime(time: number): void;
+  useEmulator(host: string, port: number): void;
 }
 
 declare module '@firebase/component' {
diff --git a/packages/storage/compat/service.ts b/packages/storage/compat/service.ts
index 3f4c0dd6870..b85aae6636f 100644
--- a/packages/storage/compat/service.ts
+++ b/packages/storage/compat/service.ts
@@ -18,9 +18,13 @@
 import * as types from '@firebase/storage-types';
 import { FirebaseApp } from '@firebase/app-types';
 
-import { StorageService, ref, _Location } from '../exp/api'; // import from the exp public API
+import { ref, _Location } from '../exp/api'; // import from the exp public API
 import { ReferenceCompat } from './reference';
-import { isUrl } from '../src/service';
+import {
+  isUrl,
+  StorageService,
+  useStorageEmulator as internalUseEmulator
+} from '../src/service';
 import { invalidArgument } from '../src/implementation/error';
 import { Compat } from '@firebase/util';
 
@@ -73,7 +77,7 @@ export class StorageServiceCompat
       );
     }
     try {
-      _Location.makeFromUrl(url);
+      _Location.makeFromUrl(url, this._delegate.host);
     } catch (e) {
       throw invalidArgument(
         'refFromUrl() expected a valid full URL but got an invalid one.'
@@ -89,4 +93,8 @@ export class StorageServiceCompat
   setMaxOperationRetryTime(time: number): void {
     this._delegate.maxOperationRetryTime = time;
   }
+
+  useEmulator(host: string, port: number): void {
+    internalUseEmulator(this._delegate, host, port);
+  }
 }
diff --git a/packages/storage/exp/index.ts b/packages/storage/exp/index.ts
index 670081acbf6..c105d1644b7 100644
--- a/packages/storage/exp/index.ts
+++ b/packages/storage/exp/index.ts
@@ -23,7 +23,10 @@ import {
 } from '@firebase/app-exp';
 
 import { XhrIoPool } from '../src/implementation/xhriopool';
-import { StorageService as StorageServiceInternal } from '../src/service';
+import {
+  StorageService as StorageServiceInternal,
+  useStorageEmulator as useEmulatorInternal
+} from '../src/service';
 import {
   Component,
   ComponentType,
@@ -36,6 +39,23 @@ import { name, version } from '../package.json';
 import { StorageService } from './public-types';
 import { STORAGE_TYPE } from './constants';
 
+/**
+ * Modify this `StorageService` instance to communicate with the Cloud Storage emulator.
+ *
+ * @param storage - The `StorageService` instance
+ * @param host - The emulator host (ex: localhost)
+ * @param port - The emulator port (ex: 5001)
+ * @public
+ */
+export function useStorageEmulator(
+  storage: StorageService,
+  host: string,
+  port: number
+): void {
+  useEmulatorInternal(storage as StorageServiceInternal, host, port);
+}
+
+export { StringFormat } from '../src/implementation/string';
 export * from './api';
 
 function factory(
diff --git a/packages/storage/package.json b/packages/storage/package.json
index 8a2ce2c9d22..a5502adf9d7 100644
--- a/packages/storage/package.json
+++ b/packages/storage/package.json
@@ -63,4 +63,4 @@
     "url": "https://github.com/firebase/firebase-js-sdk/issues"
   },
   "typings": "dist/index.d.ts"
-}
+}
\ No newline at end of file
diff --git a/packages/storage/src/implementation/location.ts b/packages/storage/src/implementation/location.ts
index 649203b7a32..a12084337fa 100644
--- a/packages/storage/src/implementation/location.ts
+++ b/packages/storage/src/implementation/location.ts
@@ -53,10 +53,10 @@ export class Location {
     return '/b/' + encode(this.bucket) + '/o';
   }
 
-  static makeFromBucketSpec(bucketString: string): Location {
+  static makeFromBucketSpec(bucketString: string, host: string): Location {
     let bucketLocation;
     try {
-      bucketLocation = Location.makeFromUrl(bucketString);
+      bucketLocation = Location.makeFromUrl(bucketString, host);
     } catch (e) {
       // Not valid URL, use as-is. This lets you put bare bucket names in
       // config.
@@ -69,7 +69,7 @@ export class Location {
     }
   }
 
-  static makeFromUrl(url: string): Location {
+  static makeFromUrl(url: string, host: string): Location {
     let location: Location | null = null;
     const bucketDomain = '([A-Za-z0-9.\\-_]+)';
 
@@ -86,7 +86,7 @@ export class Location {
       loc.path_ = decodeURIComponent(loc.path);
     }
     const version = 'v[A-Za-z0-9_]+';
-    const firebaseStorageHost = DEFAULT_HOST.replace(/[.]/g, '\\.');
+    const firebaseStorageHost = host.replace(/[.]/g, '\\.');
     const firebaseStoragePath = '(/([^?#]*).*)?$';
     const firebaseStorageRegExp = new RegExp(
       `^https?://${firebaseStorageHost}/${version}/b/${bucketDomain}/o${firebaseStoragePath}`,
@@ -95,7 +95,9 @@ export class Location {
     const firebaseStorageIndices = { bucket: 1, path: 3 };
 
     const cloudStorageHost =
-      '(?:storage.googleapis.com|storage.cloud.google.com)';
+      host === DEFAULT_HOST
+        ? '(?:storage.googleapis.com|storage.cloud.google.com)'
+        : host;
     const cloudStoragePath = '([^?#]*)';
     const cloudStorageRegExp = new RegExp(
       `^https?://${cloudStorageHost}/${bucketDomain}/${cloudStoragePath}`,
diff --git a/packages/storage/src/implementation/metadata.ts b/packages/storage/src/implementation/metadata.ts
index a877fad7c5a..14b9f6aa530 100644
--- a/packages/storage/src/implementation/metadata.ts
+++ b/packages/storage/src/implementation/metadata.ts
@@ -155,7 +155,8 @@ export function fromResourceString(
 
 export function downloadUrlFromResourceString(
   metadata: Metadata,
-  resourceString: string
+  resourceString: string,
+  host: string
 ): string | null {
   const obj = jsonObjectOrNull(resourceString);
   if (obj === null) {
@@ -176,7 +177,7 @@ export function downloadUrlFromResourceString(
     const bucket: string = metadata['bucket'] as string;
     const path: string = metadata['fullPath'] as string;
     const urlPart = '/b/' + encode(bucket) + '/o/' + encode(path);
-    const base = makeUrl(urlPart);
+    const base = makeUrl(urlPart, host);
     const queryString = makeQueryString({
       alt: 'media',
       token
diff --git a/packages/storage/src/implementation/requests.ts b/packages/storage/src/implementation/requests.ts
index bb90e6150d0..860927fcb9e 100644
--- a/packages/storage/src/implementation/requests.ts
+++ b/packages/storage/src/implementation/requests.ts
@@ -86,7 +86,11 @@ export function downloadUrlHandler(
   function handler(xhr: XhrIo, text: string): string | null {
     const metadata = fromResourceString(service, text, mappings);
     handlerCheck(metadata !== null);
-    return downloadUrlFromResourceString(metadata as Metadata, text);
+    return downloadUrlFromResourceString(
+      metadata as Metadata,
+      text,
+      service.host
+    );
   }
   return handler;
 }
@@ -143,7 +147,7 @@ export function getMetadata(
   mappings: Mappings
 ): RequestInfo<Metadata> {
   const urlPart = location.fullServerUrl();
-  const url = makeUrl(urlPart);
+  const url = makeUrl(urlPart, service.host);
   const method = 'GET';
   const timeout = service.maxOperationRetryTime;
   const requestInfo = new RequestInfo(
@@ -179,7 +183,7 @@ export function list(
     urlParams['maxResults'] = maxResults;
   }
   const urlPart = location.bucketOnlyServerUrl();
-  const url = makeUrl(urlPart);
+  const url = makeUrl(urlPart, service.host);
   const method = 'GET';
   const timeout = service.maxOperationRetryTime;
   const requestInfo = new RequestInfo(
@@ -199,7 +203,7 @@ export function getDownloadUrl(
   mappings: Mappings
 ): RequestInfo<string | null> {
   const urlPart = location.fullServerUrl();
-  const url = makeUrl(urlPart);
+  const url = makeUrl(urlPart, service.host);
   const method = 'GET';
   const timeout = service.maxOperationRetryTime;
   const requestInfo = new RequestInfo(
@@ -219,7 +223,7 @@ export function updateMetadata(
   mappings: Mappings
 ): RequestInfo<Metadata> {
   const urlPart = location.fullServerUrl();
-  const url = makeUrl(urlPart);
+  const url = makeUrl(urlPart, service.host);
   const method = 'PATCH';
   const body = toResourceString(metadata, mappings);
   const headers = { 'Content-Type': 'application/json; charset=utf-8' };
@@ -241,7 +245,7 @@ export function deleteObject(
   location: Location
 ): RequestInfo<void> {
   const urlPart = location.fullServerUrl();
-  const url = makeUrl(urlPart);
+  const url = makeUrl(urlPart, service.host);
   const method = 'DELETE';
   const timeout = service.maxOperationRetryTime;
 
@@ -321,7 +325,7 @@ export function multipartUpload(
     throw cannotSliceBlob();
   }
   const urlParams: UrlParams = { name: metadata_['fullPath']! };
-  const url = makeUrl(urlPart);
+  const url = makeUrl(urlPart, service.host);
   const method = 'POST';
   const timeout = service.maxUploadRetryTime;
   const requestInfo = new RequestInfo(
@@ -381,7 +385,7 @@ export function createResumableUpload(
   const urlPart = location.bucketOnlyServerUrl();
   const metadataForUpload = metadataForUpload_(location, blob, metadata);
   const urlParams: UrlParams = { name: metadataForUpload['fullPath']! };
-  const url = makeUrl(urlPart);
+  const url = makeUrl(urlPart, service.host);
   const method = 'POST';
   const headers = {
     'X-Goog-Upload-Protocol': 'resumable',
diff --git a/packages/storage/src/implementation/url.ts b/packages/storage/src/implementation/url.ts
index caea91f35b3..d25f3aedc51 100644
--- a/packages/storage/src/implementation/url.ts
+++ b/packages/storage/src/implementation/url.ts
@@ -18,11 +18,16 @@
 /**
  * @fileoverview Functions to create and manipulate URLs for the server API.
  */
-import { DEFAULT_HOST } from './constants';
 import { UrlParams } from './requestinfo';
 
-export function makeUrl(urlPart: string): string {
-  return `https://${DEFAULT_HOST}/v0${urlPart}`;
+export function makeUrl(urlPart: string, host: string): string {
+  const protocolMatch = host.match(/^(\w+):\/\/.+/);
+  const protocol = protocolMatch?.[1];
+  let origin = host;
+  if (protocol == null) {
+    origin = `https://${host}`;
+  }
+  return `${origin}/v0${urlPart}`;
 }
 
 export function makeQueryString(params: UrlParams): string {
diff --git a/packages/storage/src/reference.ts b/packages/storage/src/reference.ts
index db08e704c42..7431146bba3 100644
--- a/packages/storage/src/reference.ts
+++ b/packages/storage/src/reference.ts
@@ -60,7 +60,7 @@ export class Reference {
     if (location instanceof Location) {
       this._location = location;
     } else {
-      this._location = Location.makeFromUrl(location);
+      this._location = Location.makeFromUrl(location, _service.host);
     }
   }
 
diff --git a/packages/storage/src/service.ts b/packages/storage/src/service.ts
index 07a4dcdba54..b966a0a9a91 100644
--- a/packages/storage/src/service.ts
+++ b/packages/storage/src/service.ts
@@ -31,6 +31,7 @@ import {
 } from '@firebase/app-exp';
 import {
   CONFIG_STORAGE_BUCKET_KEY,
+  DEFAULT_HOST,
   DEFAULT_MAX_OPERATION_RETRY_TIME,
   DEFAULT_MAX_UPLOAD_RETRY_TIME
 } from '../src/implementation/constants';
@@ -120,12 +121,23 @@ export function ref(
   }
 }
 
-function extractBucket(config?: FirebaseOptions): Location | null {
+function extractBucket(
+  host: string,
+  config?: FirebaseOptions
+): Location | null {
   const bucketString = config?.[CONFIG_STORAGE_BUCKET_KEY];
   if (bucketString == null) {
     return null;
   }
-  return Location.makeFromBucketSpec(bucketString);
+  return Location.makeFromBucketSpec(bucketString, host);
+}
+
+export function useStorageEmulator(
+  storage: StorageService,
+  host: string,
+  port: number
+): void {
+  storage.host = `http://${host}:${port}`;
 }
 
 /**
@@ -134,7 +146,14 @@ function extractBucket(config?: FirebaseOptions): Location | null {
  * @param opt_url - gs:// url to a custom Storage Bucket
  */
 export class StorageService implements _FirebaseService {
-  readonly _bucket: Location | null = null;
+  _bucket: Location | null = null;
+  /**
+   * This string can be in the formats:
+   * - host
+   * - host:port
+   * - protocol://host:port
+   */
+  private _host: string = DEFAULT_HOST;
   protected readonly _appId: string | null = null;
   private readonly _requests: Set<Request<unknown>>;
   private _deleted: boolean = false;
@@ -155,9 +174,27 @@ export class StorageService implements _FirebaseService {
     this._maxUploadRetryTime = DEFAULT_MAX_UPLOAD_RETRY_TIME;
     this._requests = new Set();
     if (_url != null) {
-      this._bucket = Location.makeFromBucketSpec(_url);
+      this._bucket = Location.makeFromBucketSpec(_url, this._host);
+    } else {
+      this._bucket = extractBucket(this._host, this.app.options);
+    }
+  }
+
+  get host(): string {
+    return this._host;
+  }
+
+  /**
+   * Set host string for this service.
+   * @param host - host string in the form of host, host:port,
+   * or protocol://host:port
+   */
+  set host(host: string) {
+    this._host = host;
+    if (this._url != null) {
+      this._bucket = Location.makeFromBucketSpec(this._url, host);
     } else {
-      this._bucket = extractBucket(this.app.options);
+      this._bucket = extractBucket(host, this.app.options);
     }
   }
 
diff --git a/packages/storage/test/unit/requests.test.ts b/packages/storage/test/unit/requests.test.ts
index e3bf6a0d7f3..f12d1479d9f 100644
--- a/packages/storage/test/unit/requests.test.ts
+++ b/packages/storage/test/unit/requests.test.ts
@@ -200,7 +200,7 @@ describe('Firebase Storage > Requests', () => {
       const requestInfo = getMetadata(storageService, location, mappings);
       assertObjectIncludes(
         {
-          url: makeUrl(url),
+          url: makeUrl(url, storageService.host),
           method: 'GET',
           body: null,
           headers: {},
@@ -220,7 +220,7 @@ describe('Firebase Storage > Requests', () => {
     const requestInfo = list(storageService, locationRoot, '/');
     assertObjectIncludes(
       {
-        url: makeUrl(locationNormalNoObjUrl),
+        url: makeUrl(locationNormalNoObjUrl, storageService.host),
         method: 'GET',
         body: null,
         headers: {},
@@ -250,7 +250,7 @@ describe('Firebase Storage > Requests', () => {
       );
       assertObjectIncludes(
         {
-          url: makeUrl(locationNoObjectUrl),
+          url: makeUrl(locationNoObjectUrl, storageService.host),
           method: 'GET',
           body: null,
           headers: {},
@@ -317,7 +317,7 @@ describe('Firebase Storage > Requests', () => {
       const requestInfo = getDownloadUrl(storageService, location, mappings);
       assertObjectIncludes(
         {
-          url: makeUrl(url),
+          url: makeUrl(url, storageService.host),
           method: 'GET',
           body: null,
           headers: {},
@@ -352,7 +352,7 @@ describe('Firebase Storage > Requests', () => {
       );
       assertObjectIncludes(
         {
-          url: makeUrl(url),
+          url: makeUrl(url, storageService.host),
           method: 'PATCH',
           body: metadataString,
           headers: { 'Content-Type': metadataContentType },
@@ -383,7 +383,7 @@ describe('Firebase Storage > Requests', () => {
       const requestInfo = deleteObject(storageService, location);
       assertObjectIncludes(
         {
-          url: makeUrl(url),
+          url: makeUrl(url, storageService.host),
           method: 'DELETE',
           body: null,
           headers: {},
@@ -448,7 +448,7 @@ describe('Firebase Storage > Requests', () => {
 
       assertObjectIncludes(
         {
-          url: makeUrl(url),
+          url: makeUrl(url, storageService.host),
           method: 'POST',
           urlParams: { name: location.path },
           headers: {
@@ -493,7 +493,7 @@ describe('Firebase Storage > Requests', () => {
       );
       assertObjectIncludes(
         {
-          url: makeUrl(url),
+          url: makeUrl(url, storageService.host),
           method: 'POST',
           urlParams: { name: location.path },
           headers: {
diff --git a/packages/storage/test/unit/service.compat.test.ts b/packages/storage/test/unit/service.compat.test.ts
index 67886b9139a..9a79318cc2f 100644
--- a/packages/storage/test/unit/service.compat.test.ts
+++ b/packages/storage/test/unit/service.compat.test.ts
@@ -25,6 +25,8 @@ import { StorageService } from '../../src/service';
 import { FirebaseApp } from '@firebase/app-types';
 import { Provider } from '@firebase/component';
 import { FirebaseAuthInternalName } from '@firebase/auth-interop-types';
+import { TestingXhrIo } from './xhrio';
+import { Headers } from '../../src/implementation/xhrio';
 
 const fakeAppGs = testShared.makeFakeApp('gs://mybucket');
 const fakeAppGsEndingSlash = testShared.makeFakeApp('gs://mybucket/');
@@ -169,6 +171,31 @@ describe('Firebase Storage > Service', () => {
       }, 'storage/invalid-default-bucket');
     });
   });
+  describe('useStorageEmulator(service, host, port)', () => {
+    it('sets emulator host correctly', done => {
+      function newSend(
+        xhrio: TestingXhrIo,
+        url: string,
+        method: string,
+        body?: ArrayBufferView | Blob | string | null,
+        headers?: Headers
+      ): void {
+        // Expect emulator host to be in url of storage operations requests,
+        // in this case getDownloadURL.
+        expect(url).to.match(/^http:\/\/test\.host\.org:1234.+/);
+        xhrio.abort();
+        done();
+      }
+      const service = makeService(
+        testShared.fakeApp,
+        testShared.fakeAuthProvider,
+        testShared.makePool(newSend)
+      );
+      service.useEmulator('test.host.org', 1234);
+      expect(service._delegate.host).to.equal('http://test.host.org:1234');
+      void service.ref('test.png').getDownloadURL();
+    });
+  });
   describe('refFromURL', () => {
     const service = makeService(
       testShared.fakeApp,
diff --git a/packages/storage/test/unit/service.exp.test.ts b/packages/storage/test/unit/service.exp.test.ts
index eee6568e2ec..6f4d0a3d2f2 100644
--- a/packages/storage/test/unit/service.exp.test.ts
+++ b/packages/storage/test/unit/service.exp.test.ts
@@ -16,17 +16,20 @@
  */
 import { expect } from 'chai';
 import { TaskEvent } from '../../src/implementation/taskenums';
+import { Headers } from '../../src/implementation/xhrio';
 import { XhrIoPool } from '../../src/implementation/xhriopool';
-import { StorageService, ref } from '../../src/service';
+import { StorageService, ref, useStorageEmulator } from '../../src/service';
 import * as testShared from './testshared';
 import { DEFAULT_HOST } from '../../src/implementation/constants';
 import { FirebaseStorageError } from '../../src/implementation/error';
 import {
   Reference,
   getMetadata,
-  uploadBytesResumable
+  uploadBytesResumable,
+  getDownloadURL
 } from '../../src/reference';
 import { Location } from '../../src/implementation/location';
+import { TestingXhrIo } from './xhrio';
 
 const fakeAppGs = testShared.makeFakeApp('gs://mybucket');
 const fakeAppGsEndingSlash = testShared.makeFakeApp('gs://mybucket/');
@@ -217,6 +220,31 @@ GOOG4-RSA-SHA256`
       );
     });
   });
+  describe('useStorageEmulator(service, host, port)', () => {
+    it('sets emulator host correctly', done => {
+      function newSend(
+        xhrio: TestingXhrIo,
+        url: string,
+        method: string,
+        body?: ArrayBufferView | Blob | string | null,
+        headers?: Headers
+      ): void {
+        // Expect emulator host to be in url of storage operations requests,
+        // in this case getDownloadURL.
+        expect(url).to.match(/^http:\/\/test\.host\.org:1234.+/);
+        xhrio.abort();
+        done();
+      }
+      const service = new StorageService(
+        testShared.fakeApp,
+        testShared.fakeAuthProvider,
+        testShared.makePool(newSend)
+      );
+      useStorageEmulator(service, 'test.host.org', 1234);
+      expect(service.host).to.equal('http://test.host.org:1234');
+      void getDownloadURL(ref(service, 'test.png'));
+    });
+  });
   describe('ref(service, path)', () => {
     const service = new StorageService(
       testShared.fakeApp,