diff --git a/examples/02_gui.py b/examples/02_gui.py
index 70eb07542..5e09ef8ab 100644
--- a/examples/02_gui.py
+++ b/examples/02_gui.py
@@ -81,7 +81,9 @@ def main() -> None:
 
     @gui_upload_button.on_upload
     def _(_) -> None:
-        print(gui_upload_button.value.name)
+        """Callback for when a file is uploaded."""
+        file = gui_upload_button.value
+        print(file.name, len(file.content), "bytes")
 
     # Pre-generate a point cloud to send.
     point_positions = onp.random.uniform(low=-1.0, high=1.0, size=(5000, 3))
diff --git a/src/viser/client/src/components/UploadButton.tsx b/src/viser/client/src/components/UploadButton.tsx
new file mode 100644
index 000000000..108b3288d
--- /dev/null
+++ b/src/viser/client/src/components/UploadButton.tsx
@@ -0,0 +1,205 @@
+import { GuiAddUploadButtonMessage } from "../WebsocketMessages";
+import { computeRelativeLuminance } from "../ControlPanel/GuiState";
+import { GuiComponentContext } from "../ControlPanel/GuiComponentContext";
+import { v4 as uuid } from "uuid";
+import { Box, Image, Progress, useMantineTheme } from "@mantine/core";
+
+import { Button } from "@mantine/core";
+import React, { useContext } from "react";
+import { makeThrottledMessageSender } from "../WebsocketFunctions";
+import { ViewerContext, ViewerContextContents } from "../App";
+import { pack } from "msgpackr";
+import { IconCheck } from "@tabler/icons-react";
+import { notifications } from "@mantine/notifications";
+
+export default function UploadButtonComponent(conf: GuiAddUploadButtonMessage) {
+  // Handle GUI input types.
+  const viewer = useContext(ViewerContext)!;
+  const fileUploadRef = React.useRef<HTMLInputElement>(null);
+  const { isUploading, upload } = useFileUpload({
+    viewer,
+    componentId: conf.id,
+  });
+  const theme = useMantineTheme();
+
+  const inputColor =
+    computeRelativeLuminance(theme.fn.primaryColor()) > 50.0
+      ? theme.colors.gray[9]
+      : theme.white;
+  const disabled = conf.disabled || isUploading;
+  return (
+    <Box mx="xs" mb="0.5em">
+      <input
+        type="file"
+        style={{ display: "none" }}
+        id={`file_upload_${conf.id}`}
+        name="file"
+        accept={conf.mime_type}
+        ref={fileUploadRef}
+        onChange={(e) => {
+          const input = e.target as HTMLInputElement;
+          if (!input.files) return;
+          upload(input.files[0]);
+        }}
+      />
+      <Button
+        id={conf.id}
+        fullWidth
+        color={conf.color ?? undefined}
+        onClick={() => {
+          if (fileUploadRef.current === null) return;
+          fileUploadRef.current.value = fileUploadRef.current.defaultValue;
+          fileUploadRef.current.click();
+        }}
+        style={{ height: "2.125em" }}
+        styles={{ inner: { color: inputColor + " !important" } }}
+        disabled={disabled}
+        size="sm"
+        leftIcon={
+          conf.icon_base64 === null ? undefined : (
+            <Image
+              /*^In Safari, both the icon's height and width need to be set, otherwise the icon is clipped.*/
+              height="1em"
+              width="1em"
+              opacity={disabled ? 0.3 : 1.0}
+              mr="-0.125em"
+              sx={
+                inputColor === theme.white
+                  ? {
+                      // Make the color white.
+                      filter: !disabled ? "invert(1)" : undefined,
+                    }
+                  : // Icon will be black by default.
+                    undefined
+              }
+              src={"data:image/svg+xml;base64," + conf.icon_base64}
+            />
+          )
+        }
+      >
+        {conf.label}
+      </Button>
+    </Box>
+  );
+}
+
+function useFileUpload({
+  viewer,
+  componentId,
+}: {
+  componentId: string;
+  viewer: ViewerContextContents;
+}) {
+  const websocketRef = viewer.websocketRef;
+  const updateUploadState = viewer.useGui((state) => state.updateUploadState);
+  const uploadState = viewer.useGui(
+    (state) => state.uploadsInProgress[componentId],
+  );
+  const totalBytes = uploadState?.totalBytes;
+
+  // Cache total bytes string
+  const totalBytesString = React.useMemo(() => {
+    if (totalBytes === undefined) return "";
+    let displaySize = totalBytes;
+    const displayUnits = ["B", "K", "M", "G", "T", "P"];
+    let displayUnitIndex = 0;
+    while (displaySize >= 100 && displayUnitIndex < displayUnits.length - 1) {
+      displaySize /= 1024;
+      displayUnitIndex += 1;
+    }
+    return `${displaySize.toFixed(1)}${displayUnits[displayUnitIndex]}`;
+  }, [totalBytes]);
+
+  // Update notification status
+  React.useEffect(() => {
+    if (uploadState === undefined) return;
+    const { notificationId, filename } = uploadState;
+    if (uploadState.uploadedBytes === 0) {
+      // Show notification.
+      notifications.show({
+        id: notificationId,
+        title: "Uploading " + `${filename} (${totalBytesString})`,
+        message: <Progress size="sm" value={0} />,
+        autoClose: false,
+        withCloseButton: false,
+        loading: true,
+      });
+    } else {
+      // Update progress.
+      const progressValue = uploadState.uploadedBytes / uploadState.totalBytes;
+      const isDone = progressValue === 1.0;
+      notifications.update({
+        id: notificationId,
+        title: "Uploading " + `${filename} (${totalBytesString})`,
+        message: !isDone ? (
+          <Progress
+            size="sm"
+            // Default transition time is 100ms.
+            // In Mantine v7, the transitionDuration prop can be used.
+            styles={{ bar: { transition: "width 10ms linear" } }}
+            value={100 * progressValue}
+          />
+        ) : (
+          "File uploaded successfully."
+        ),
+        autoClose: isDone,
+        withCloseButton: isDone,
+        loading: !isDone,
+        icon: isDone ? <IconCheck /> : undefined,
+      });
+    }
+  }, [uploadState, totalBytesString]);
+
+  const isUploading =
+    uploadState !== undefined &&
+    uploadState.uploadedBytes < uploadState.totalBytes;
+
+  async function upload(file: File) {
+    const chunkSize = 512 * 1024; // bytes
+    const numChunks = Math.ceil(file.size / chunkSize);
+    const transferUuid = uuid();
+    const notificationId = "upload-" + transferUuid;
+
+    const send = (message: Parameters<typeof pack>[0]) =>
+      websocketRef.current?.send(pack(message));
+
+    // Begin upload by setting initial state
+    updateUploadState({
+      componentId: componentId,
+      uploadedBytes: 0,
+      totalBytes: file.size,
+      filename: file.name,
+      notificationId,
+    });
+
+    send({
+      type: "FileTransferStart",
+      source_component_id: componentId,
+      transfer_uuid: transferUuid,
+      filename: file.name,
+      mime_type: file.type,
+      size_bytes: file.size,
+      part_count: numChunks,
+    });
+
+    for (let i = 0; i < numChunks; i++) {
+      const start = i * chunkSize;
+      const end = (i + 1) * chunkSize;
+      const chunk = file.slice(start, end);
+      const buffer = await chunk.arrayBuffer();
+
+      send({
+        type: "FileTransferPart",
+        source_component_id: componentId,
+        transfer_uuid: transferUuid,
+        part: i,
+        content: new Uint8Array(buffer),
+      });
+    }
+  }
+
+  return {
+    isUploading,
+    upload,
+  };
+}