diff --git a/src/plugins/platforms/wasm/qtloader.js b/src/plugins/platforms/wasm/qtloader.js
index 4ce27de6a54..5f3f2d1a91c 100644
--- a/src/plugins/platforms/wasm/qtloader.js
+++ b/src/plugins/platforms/wasm/qtloader.js
@@ -29,6 +29,23 @@
  *      The path is set to 'qt' by default, and is relative to the path of the web page's html file.
  *      This property is not in use when static linking is used, since this build mode includes all
  *      libraries and plugins in the wasm file.
+ * - preload: [string]: Array of file paths to json-encoded files which specifying which files to preload.
+ *      The preloaded files will be downloaded at application startup and copied to the in-memory file
+ *      system provided by Emscripten.
+ *
+ *      Each json file must contain an array of source, destination objects:
+ *      [
+ *           {
+ *               "source": "path/to/source",
+ *               "destination": "/path/to/destination"
+ *           },
+ *           ...
+ *      ]
+ *      The source path is relative to the html file path. The destination path must be
+ *      an absolute path.
+ *
+ *      $QTDIR may be used as a placeholder for the "qtdir" configuration property (see @qtdir), for instance:
+ *          "source": "$QTDIR/plugins/imageformats/libqjpeg.so"
  *
  * @return Promise<instance: EmscriptenModule>
  *      The promise is resolved when the module has been instantiated and its main function has been
@@ -49,6 +66,16 @@ async function qtLoad(config)
             throw new Error('ENV must be exported if environment variables are passed');
     };
 
+    const throwIfFsUsedButNotExported = (instance, config) =>
+    {
+        const environment = config.environment;
+        if (!environment || Object.keys(environment).length === 0)
+            return;
+        const isFsExported = typeof instance.FS === 'object';
+        if (!isFsExported)
+            throw new Error('FS must be exported if preload is used');
+    };
+
     if (typeof config !== 'object')
         throw new Error('config is required, expected an object');
     if (typeof config.qt !== 'object')
@@ -57,6 +84,7 @@ async function qtLoad(config)
         throw new Error('config.qt.entryFunction is required, expected a function');
 
     config.qt.qtdir ??= 'qt';
+    config.qt.preload ??= [];
 
     config.qtContainerElements = config.qt.containerElements;
     delete config.qt.containerElements;
@@ -91,6 +119,30 @@ async function qtLoad(config)
         throwIfEnvUsedButNotExported(instance, config);
         for (const [name, value] of Object.entries(config.qt.environment ?? {}))
             instance.ENV[name] = value;
+
+        const makeDirs = (FS, filePath) => {
+            const parts = filePath.split("/");
+            let path = "/";
+            for (let i = 0; i < parts.length - 1; ++i) {
+                const part = parts[i];
+                if (part == "")
+                    continue;
+                path += part + "/";
+                try {
+                    FS.mkdir(path);
+                } catch (error) {
+                    const EEXIST = 20;
+                    if (error.errno != EEXIST)
+                        throw error;
+                }
+            }
+        }
+
+        throwIfFsUsedButNotExported(instance, config);
+        for ({destination, data} of self.preloadData) {
+            makeDirs(instance.FS, destination);
+            instance.FS.writeFile(destination, new Uint8Array(data));
+        }
     };
 
     config.onRuntimeInitialized = () => config.qt.onLoaded?.();
@@ -137,6 +189,22 @@ async function qtLoad(config)
         });
     };
 
+    const fetchPreloadFiles = async () => {
+        const fetchJson = async path => (await fetch(path)).json();
+        const fetchArrayBuffer = async path => (await fetch(path)).arrayBuffer();
+        const loadFiles = async (paths) => {
+            const source = paths['source'].replace('$QTDIR', config.qt.qtdir);
+            return {
+                destination: paths['destination'],
+                data: await fetchArrayBuffer(source)
+            };
+        }
+        const fileList = (await Promise.all(config.qt.preload.map(fetchJson))).flat();
+        self.preloadData = (await Promise.all(fileList.map(loadFiles))).flat();
+    }
+
+    await fetchPreloadFiles();
+
     // Call app/emscripten module entry function. It may either come from the emscripten
     // runtime script or be customized as needed.
     const instance = await Promise.race(
diff --git a/tests/manual/wasm/qtloader_integration/CMakeLists.txt b/tests/manual/wasm/qtloader_integration/CMakeLists.txt
index 24c5607cd88..2603a05135c 100644
--- a/tests/manual/wasm/qtloader_integration/CMakeLists.txt
+++ b/tests/manual/wasm/qtloader_integration/CMakeLists.txt
@@ -37,3 +37,9 @@ add_custom_command(
     COMMAND ${CMAKE_COMMAND} -E copy
             ${CMAKE_CURRENT_SOURCE_DIR}/test_body.js
             ${CMAKE_CURRENT_BINARY_DIR}/test_body.js)
+
+add_custom_command(
+    TARGET tst_qtloader_integration POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy
+            ${CMAKE_CURRENT_SOURCE_DIR}/preload.json
+            ${CMAKE_CURRENT_BINARY_DIR}/preload.json)
diff --git a/tests/manual/wasm/qtloader_integration/main.cpp b/tests/manual/wasm/qtloader_integration/main.cpp
index ed8a57bcc6e..b9bed0d49b0 100644
--- a/tests/manual/wasm/qtloader_integration/main.cpp
+++ b/tests/manual/wasm/qtloader_integration/main.cpp
@@ -49,6 +49,21 @@ std::string logicalDpi()
     return out.str();
 }
 
+std::string preloadedFiles()
+{
+    QStringList files = QDir("/preload").entryList(QDir::Files);
+    std::ostringstream out;
+    out << "[";
+    const char *separator = "";
+    for (const auto &file : files) {
+        out << separator;
+        out << file.toStdString();
+        separator = ",";
+    }
+    out << "]";
+    return out.str();
+}
+
 void crash()
 {
     std::abort();
@@ -145,6 +160,7 @@ EMSCRIPTEN_BINDINGS(qtLoaderIntegrationTest)
 
     emscripten::function("screenInformation", &screenInformation);
     emscripten::function("logicalDpi", &logicalDpi);
+    emscripten::function("preloadedFiles", &preloadedFiles);
     emscripten::function("crash", &crash);
     emscripten::function("exitApp", &exitApp);
     emscripten::function("produceOutput", &produceOutput);
diff --git a/tests/manual/wasm/qtloader_integration/preload.json b/tests/manual/wasm/qtloader_integration/preload.json
new file mode 100644
index 00000000000..d7e09911ff8
--- /dev/null
+++ b/tests/manual/wasm/qtloader_integration/preload.json
@@ -0,0 +1,10 @@
+[
+    {
+        "source": "qtloader.js",
+        "destination": "/preload/qtloader.js"
+    },
+    {
+        "source": "$QTDIR/qtlogo.svg",
+        "destination": "/preload/qtlogo.svg"
+    }
+]
diff --git a/tests/manual/wasm/qtloader_integration/test_body.js b/tests/manual/wasm/qtloader_integration/test_body.js
index 385a3816d3f..233c64f2f60 100644
--- a/tests/manual/wasm/qtloader_integration/test_body.js
+++ b/tests/manual/wasm/qtloader_integration/test_body.js
@@ -439,6 +439,20 @@ export class QtLoaderIntegrationTests
         assert.equal('ExitStatus', exception.name);
     }
 
+    async preloadFiles()
+    {
+        const instance = await qtLoad({
+            arguments: ["--no-gui"],
+            qt: {
+                preload: ['preload.json'],
+                qtdir: '.',
+            }
+        });
+        const preloadedFiles = instance.preloadedFiles();
+        // Verify that preloaded file list matches files specified in preload.json
+        assert.equal("[qtloader.js,qtlogo.svg]", preloadedFiles);
+    }
+
     #callTestInstanceApi(instance, apiName)
     {
         return eval(instance[apiName]());