diff --git a/.changeset/plenty-lizards-cheat.md b/.changeset/plenty-lizards-cheat.md
new file mode 100644
index 000000000000..155bfa87f781
--- /dev/null
+++ b/.changeset/plenty-lizards-cheat.md
@@ -0,0 +1,8 @@
+---
+"@gradio/lite": patch
+"@gradio/wasm": patch
+"@self/tootils": patch
+"gradio": patch
+---
+
+fix:Fix Lite to work on FireFox
diff --git a/.config/playwright.config.js b/.config/playwright.config.js
index 6b5f971c16b6..01d9b1ce1215 100644
--- a/.config/playwright.config.js
+++ b/.config/playwright.config.js
@@ -56,7 +56,18 @@ const lite = defineConfig(base, {
 	],
 	workers: 1,
 	retries: 3,
-	timeout: 60000
+	timeout: 60000,
+	projects: [
+		{
+			name: "chromium",
+			use: { ...devices["Desktop Chrome"] }
+		},
+		{
+			name: "firefox",
+			use: { ...devices["Desktop Firefox"] },
+			testIgnore: "**/kitchen_sink.*" // This test requires the camera permission but it's not supported on FireFox: https://github.com/microsoft/playwright/issues/11714
+		}
+	]
 });
 
 export default !!process.env.GRADIO_E2E_TEST_LITE ? lite : normal;
diff --git a/gradio/processing_utils.py b/gradio/processing_utils.py
index 783b93591790..b833d721bbe1 100644
--- a/gradio/processing_utils.py
+++ b/gradio/processing_utils.py
@@ -95,7 +95,13 @@ async def handle_async_request(
         ) -> httpx.Response:
             url = str(request.url)
             method = request.method
+
             headers = dict(request.headers)
+            # User-agent header is automatically set by the browser.
+            # More importantly, setting it causes an error on FireFox where a preflight request is made and it leads to a CORS error.
+            # Maybe related to https://bugzilla.mozilla.org/show_bug.cgi?id=1629921
+            del headers["user-agent"]
+
             body = None if method in ["GET", "HEAD"] else await request.aread()
             response = await pyodide.http.pyfetch(
                 url, method=method, headers=headers, body=body
diff --git a/js/lite/src/fetch.ts b/js/lite/src/fetch.ts
index 4cc63f45c662..3349df65acff 100644
--- a/js/lite/src/fetch.ts
+++ b/js/lite/src/fetch.ts
@@ -44,12 +44,14 @@ export async function wasm_proxied_fetch(
 		headers[key] = value;
 	});
 
+	const body = request.body ?? new Uint8Array(await request.arrayBuffer()); // request.body can't be read on FireFox, so fallback to arrayBuffer().
+
 	const response = await workerProxy.httpRequest({
 		path: url.pathname,
 		query_string: url.searchParams.toString(), // The `query_string` field in the ASGI spec must not contain the leading `?`.
 		method,
 		headers,
-		body: request.body
+		body
 	});
 	return new Response(response.body, {
 		status: response.status,
diff --git a/js/spa/test/file_component_events.spec.ts b/js/spa/test/file_component_events.spec.ts
index 48fdca532ebc..f20072b97443 100644
--- a/js/spa/test/file_component_events.spec.ts
+++ b/js/spa/test/file_component_events.spec.ts
@@ -11,12 +11,14 @@ async function error_modal_showed(page) {
 test("File component properly dispatches load event for the single file case.", async ({
 	page
 }) => {
-	await page
-		.getByRole("button", { name: "Drop File Here - or - Click to Upload" })
-		.first()
-		.click();
-	const uploader = await page.locator("input[type=file]").first();
-	await uploader.setInputFiles(["./test/files/cheetah1.jpg"]);
+	const [fileChooser] = await Promise.all([
+		page.waitForEvent("filechooser"),
+		page
+			.getByRole("button", { name: "Drop File Here - or - Click to Upload" })
+			.first()
+			.click()
+	]);
+	await fileChooser.setFiles(["./test/files/cheetah1.jpg"]);
 
 	await expect(page.getByLabel("# Load Upload Single File")).toHaveValue("1");
 
diff --git a/js/spa/test/gallery_component_events.spec.ts b/js/spa/test/gallery_component_events.spec.ts
index a0bc9c82b9b7..8e34acc0afa0 100644
--- a/js/spa/test/gallery_component_events.spec.ts
+++ b/js/spa/test/gallery_component_events.spec.ts
@@ -33,12 +33,14 @@ test("Gallery select event returns the right value and the download button works
 test("Gallery click-to-upload, upload and change events work correctly", async ({
 	page
 }) => {
-	await page
-		.getByRole("button", { name: "Drop Media Here - or - Click to Upload" })
-		.first()
-		.click();
-	const uploader = await page.locator("input[type=file]").first();
-	await uploader.setInputFiles([
+	const [fileChooser] = await Promise.all([
+		page.waitForEvent("filechooser"),
+		page
+			.getByRole("button", { name: "Drop Media Here - or - Click to Upload" })
+			.first()
+			.click()
+	]);
+	await fileChooser.setFiles([
 		"./test/files/cheetah1.jpg",
 		"./test/files/cheetah1.jpg"
 	]);
diff --git a/js/spa/test/outbreak_forecast.spec.ts b/js/spa/test/outbreak_forecast.spec.ts
index b0e638904b02..d7a86747d137 100644
--- a/js/spa/test/outbreak_forecast.spec.ts
+++ b/js/spa/test/outbreak_forecast.spec.ts
@@ -1,4 +1,4 @@
-import { test, expect } from "@self/tootils";
+import { test, expect, is_lite } from "@self/tootils";
 
 test("selecting matplotlib should show matplotlib image and pressing clear should clear output", async ({
 	page
@@ -20,8 +20,14 @@ test("selecting matplotlib should show matplotlib image and pressing clear shoul
 });
 
 test("selecting plotly should show plotly plot and pressing clear should clear output", async ({
-	page
+	page,
+	browserName
 }) => {
+	test.fixme(
+		browserName === "firefox" && is_lite,
+		"Plotly component can't be located on Lite on FireFox in the CI env for some reason"
+	);
+
 	await page.getByLabel("Plot Type").click();
 	await page.getByRole("option", { name: "Plotly" }).click();
 	await page.getByLabel("Month").click();
@@ -29,9 +35,12 @@ test("selecting plotly should show plotly plot and pressing clear should clear o
 	await page.getByLabel("Social Distancing?").check();
 
 	await page.click("text=Submit");
-	await expect(page.locator(".js-plotly-plot")).toHaveCount(1);
+
+	const plotly_plot = page.getByTestId("plotly");
+	await expect(plotly_plot).toHaveCount(1);
+
 	await page.getByRole("button", { name: "Clear" }).click();
-	await expect(page.locator(".js-plotly-plot")).toHaveCount(0);
+	await expect(plotly_plot).toHaveCount(0);
 });
 
 test("selecting altair should show altair plot and pressing clear should clear output", async ({
@@ -45,7 +54,7 @@ test("selecting altair should show altair plot and pressing clear should clear o
 
 	await page.click("text=Submit");
 
-	const altair = await page.getByTestId("altair");
+	const altair = page.getByTestId("altair");
 	await expect(altair).toHaveCount(1);
 
 	await page.getByRole("button", { name: "Clear" }).click();
@@ -63,7 +72,7 @@ test("selecting bokeh should show bokeh plot and pressing clear should clear out
 
 	await page.click("text=Submit");
 
-	const altair = await page.getByTestId("bokeh");
+	const altair = page.getByTestId("bokeh");
 	await expect(altair).toHaveCount(1);
 
 	await page.getByRole("button", { name: "Clear" }).click();
@@ -71,8 +80,14 @@ test("selecting bokeh should show bokeh plot and pressing clear should clear out
 });
 
 test("switching between all 4 plot types and pressing submit should update output component to corresponding plot type", async ({
-	page
+	page,
+	browserName
 }) => {
+	test.fixme(
+		browserName === "firefox" && is_lite,
+		"Plotly component can't be located on Lite on FireFox in the CI env for some reason"
+	);
+
 	//Matplotlib
 	await page.getByLabel("Plot Type").click();
 	await page.getByRole("option", { name: "Matplotlib" }).click();
@@ -91,7 +106,8 @@ test("switching between all 4 plot types and pressing submit should update outpu
 	await page.getByRole("option", { name: "Plotly" }).click();
 
 	await page.click("text=Submit");
-	await expect(page.locator(".js-plotly-plot")).toHaveCount(1);
+	const plotly = page.getByTestId("plotly");
+	await expect(plotly).toHaveCount(1);
 
 	//Altair
 	await page.getByLabel("Plot Type").click();
diff --git a/js/tootils/src/index.ts b/js/tootils/src/index.ts
index bc5bce7cbf77..25d7e58a001a 100644
--- a/js/tootils/src/index.ts
+++ b/js/tootils/src/index.ts
@@ -21,7 +21,7 @@ const ROOT_DIR = path.resolve(
 	"../../../.."
 );
 
-const is_lite = !!process.env.GRADIO_E2E_TEST_LITE;
+export const is_lite = !!process.env.GRADIO_E2E_TEST_LITE;
 
 const test_normal = base.extend<{ setup: void }>({
 	setup: [
diff --git a/js/wasm/src/cross-origin-worker.ts b/js/wasm/src/cross-origin-worker.ts
index 12c11f3f3b05..5a6b257d092e 100644
--- a/js/wasm/src/cross-origin-worker.ts
+++ b/js/wasm/src/cross-origin-worker.ts
@@ -26,20 +26,32 @@ function get_blob_url(url: URL): string {
 	return worker_blob_url;
 }
 
+function is_same_origin(url: URL): boolean {
+	return url.origin === window.location.origin;
+}
+
 export class CrossOriginWorkerMaker {
 	public readonly worker: Worker | SharedWorker;
 
 	constructor(url: URL, options?: WorkerOptions & { shared?: boolean }) {
 		const { shared = false, ...workerOptions } = options ?? {};
 
-		try {
+		if (is_same_origin(url)) {
+			console.debug(
+				`Loading a worker script from the same origin: ${url.toString()}.`
+			);
 			// This is the normal way to load a worker script, which is the best straightforward if possible.
 			this.worker = shared
 				? new SharedWorker(url, workerOptions)
 				: new Worker(url, workerOptions);
-		} catch (e) {
+
+			// NOTE: We use here `if-else` checking the origin instead of `try-catch`
+			// because the `try-catch` approach doesn't work on some browsers like FireFox.
+			// In the cross-origin case, FireFox throws a SecurityError asynchronously after the worker is created,
+			// so we can't catch the error synchronously.
+		} else {
 			console.debug(
-				`Failed to load a worker script from ${url.toString()}. Trying to load a cross-origin worker...`
+				`Loading a worker script from a different origin: ${url.toString()}.`
 			);
 			const worker_blob_url = get_blob_url(url);
 			this.worker = shared