diff --git a/website/src/lib/components/Data.svelte b/website/src/lib/components/Data.svelte
index 469bb33b..62b6ff0e 100644
--- a/website/src/lib/components/Data.svelte
+++ b/website/src/lib/components/Data.svelte
@@ -1,9 +1,9 @@
 <script lang="ts">
 	import GPX from './GPX.svelte';
 
-	import { files } from '$lib/stores';
+	import { fileCollection } from '$lib/stores';
 </script>
 
-{#each $files as file}
+{#each $fileCollection.files as file}
 	<GPX {file} />
 {/each}
diff --git a/website/src/lib/components/ElevationProfile.svelte b/website/src/lib/components/ElevationProfile.svelte
index d76de02a..8db73bff 100644
--- a/website/src/lib/components/ElevationProfile.svelte
+++ b/website/src/lib/components/ElevationProfile.svelte
@@ -6,7 +6,7 @@
 	import Chart from 'chart.js/auto';
 	import mapboxgl from 'mapbox-gl';
 
-	import { map, files, fileOrder, selectedFiles } from '$lib/stores';
+	import { map, fileCollection, fileOrder, selectedFiles } from '$lib/stores';
 
 	import { onDestroy, onMount } from 'svelte';
 	import {
@@ -75,10 +75,10 @@
 			},
 			tooltip: {
 				callbacks: {
-					title: function (context) {
+					title: function () {
 						return '';
 					},
-					label: function (context) {
+					label: function (context: Chart.TooltipContext) {
 						let point = context.raw;
 						if (context.datasetIndex === 0) {
 							let elevation = point.y.toFixed(0);
@@ -104,7 +104,7 @@
 							return `Power: ${power} W`;
 						}
 					},
-					afterBody: function (contexts) {
+					afterBody: function (contexts: Chart.TooltipContext[]) {
 						let context = contexts.filter((context) => context.datasetIndex === 0);
 						if (context.length === 0) return;
 						let point = context[0].raw;
@@ -124,7 +124,13 @@
 		stacked: false
 	};
 
-	let datasets = {
+	let datasets: {
+		[key: string]: {
+			id: string;
+			label: string;
+			units: string;
+		};
+	} = {
 		speed: {
 			id: 'speed',
 			label: 'Speed',
@@ -179,7 +185,7 @@
 				{
 					id: 'toggleMarker',
 					events: ['mouseout'],
-					afterEvent: function (chart, args) {
+					afterEvent: function (chart: Chart, args: { event: Chart.ChartEvent }) {
 						if (args.event.type === 'mouseout') {
 							if ($map && marker) {
 								marker.remove();
@@ -194,7 +200,7 @@
 
 	$: if (chart) {
 		let gpxFiles = new GPXFiles(Array.from($selectedFiles));
-		let order = $fileOrder.length == 0 ? $files : $fileOrder;
+		let order = $fileOrder.length == 0 ? $fileCollection.files : $fileOrder;
 		gpxFiles.files.sort(function (a, b) {
 			return order.indexOf(a) - order.indexOf(b);
 		});
diff --git a/website/src/lib/components/FileList.svelte b/website/src/lib/components/FileList.svelte
index b4330daa..9f91474c 100644
--- a/website/src/lib/components/FileList.svelte
+++ b/website/src/lib/components/FileList.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { fileOrder, files, selectedFiles, selectFiles } from '$lib/stores';
+	import { fileOrder, fileCollection, selectedFiles, selectFiles } from '$lib/stores';
 
 	import { ScrollArea } from '$lib/components/ui/scroll-area/index';
 	import Sortable from 'sortablejs/Sortable';
@@ -30,7 +30,7 @@
 
 	function selectAllFiles() {
 		selectedFiles.update((selectedFiles) => {
-			get(files).forEach((file) => {
+			get(fileCollection).files.forEach((file) => {
 				selectedFiles.add(file);
 			});
 			return selectedFiles;
@@ -53,12 +53,12 @@
 			avoidImplicitDeselect: true,
 			onSelect: (e) => {
 				const index = parseInt(e.item.getAttribute('data-id'));
-				addSelectFile($files[index]);
+				addSelectFile($fileCollection.files[index]);
 				if (!e.originalEvent.shiftKey && $selectedFiles.size > 1) {
 					$selectedFiles.forEach((file) => {
-						if (file !== $files[index]) {
+						if (file !== $fileCollection.files[index]) {
 							deselectFile(file);
-							const index = $files.indexOf(file);
+							const index = $fileCollection.files.indexOf(file);
 							Sortable.utils.deselect(buttons[index]);
 						}
 					});
@@ -66,10 +66,12 @@
 			},
 			onDeselect: (e) => {
 				const index = parseInt(e.item.getAttribute('data-id'));
-				deselectFile($files[index]);
+				deselectFile($fileCollection.files[index]);
 			},
 			onSort: () => {
-				$fileOrder = sortable.toArray().map((index) => $files[parseInt(index)]);
+				$fileOrder = sortable
+					.toArray()
+					.map((index: string) => $fileCollection.files[parseInt(index)]);
 			}
 		});
 	});
@@ -82,23 +84,23 @@
 						Sortable.utils.deselect(button);
 					}
 				});
-				const index = $files.indexOf(file);
+				const index = $fileCollection.files.indexOf(file);
 				Sortable.utils.select(buttons[index]);
 				selectFile(file);
 			},
 			addSelect: (file: GPXFile) => {
-				const index = $files.indexOf(file);
+				const index = $fileCollection.files.indexOf(file);
 				Sortable.utils.select(buttons[index]);
 				addSelectFile(file);
 			},
 			selectAllFiles: () => {
-				$files.forEach((file, index) => {
+				$fileCollection.files.forEach((file, index) => {
 					Sortable.utils.select(buttons[index]);
 				});
 				selectAllFiles();
 			},
 			removeSelect: (file: GPXFile) => {
-				const index = $files.indexOf(file);
+				const index = $fileCollection.files.indexOf(file);
 				Sortable.utils.deselect(buttons[index]);
 				deselectFile(file);
 			}
@@ -109,7 +111,7 @@
 <div class="absolute h-10 -translate-y-10 w-fit max-w-full bg-secondary rounded-t">
 	<ScrollArea orientation="horizontal" class="w-full h-full" scrollbarXClasses="h-2">
 		<div bind:this={tabs} class="flex flex-row gap-1">
-			{#each $files as file, index}
+			{#each $fileCollection.files as file, index}
 				<button
 					bind:this={buttons[index]}
 					data-id={index}
diff --git a/website/src/lib/components/GPX.svelte b/website/src/lib/components/GPX.svelte
index b9be5bb4..432d556b 100644
--- a/website/src/lib/components/GPX.svelte
+++ b/website/src/lib/components/GPX.svelte
@@ -41,7 +41,7 @@
 <script lang="ts">
 	import { onDestroy, onMount } from 'svelte';
 	import { GPXFile } from 'gpx';
-	import { map, selectedFiles, selectFiles, files } from '$lib/stores';
+	import { map, selectedFiles, selectFiles, fileCollection } from '$lib/stores';
 	import { get } from 'svelte/store';
 
 	export let file: GPXFile;
@@ -127,7 +127,7 @@
 	onMount(() => {
 		addGPXLayer();
 		if ($map) {
-			if ($files.length == 1) {
+			if ($fileCollection.files.length == 1) {
 				$map.fitBounds([file.statistics.bounds.southWest, file.statistics.bounds.northEast], {
 					padding: 60,
 					linear: true,
diff --git a/website/src/lib/components/Menu.svelte b/website/src/lib/components/Menu.svelte
index f17f8c56..89962d17 100644
--- a/website/src/lib/components/Menu.svelte
+++ b/website/src/lib/components/Menu.svelte
@@ -15,7 +15,7 @@
 	} from 'lucide-svelte';
 
 	import {
-		files,
+		fileCollection,
 		selectedFiles,
 		duplicateSelectedFiles,
 		exportAllFiles,
@@ -62,7 +62,7 @@
 					<Menubar.Item on:click={exportSelectedFiles} disabled={$selectedFiles.size == 0}>
 						<Download size="16" class="mr-1" /> Export... <Menubar.Shortcut>⌘S</Menubar.Shortcut>
 					</Menubar.Item>
-					<Menubar.Item on:click={exportAllFiles} disabled={$files.length == 0}>
+					<Menubar.Item on:click={exportAllFiles} disabled={$fileCollection.files.length == 0}>
 						<Download size="16" class="mr-1" /> Export all... <Menubar.Shortcut
 							>⇧⌘S</Menubar.Shortcut
 						>
@@ -86,7 +86,7 @@
 					<Menubar.Item
 						class="text-destructive data-[highlighted]:text-destructive"
 						on:click={removeAllFiles}
-						disabled={$files.length == 0}
+						disabled={$fileCollection.files.length == 0}
 					>
 						<Trash2 size="16" class="mr-1" /> Delete all<Menubar.Shortcut>⇧⌘⌫</Menubar.Shortcut
 						></Menubar.Item
diff --git a/website/src/lib/stores.ts b/website/src/lib/stores.ts
index 3b7ee022..df4910c9 100644
--- a/website/src/lib/stores.ts
+++ b/website/src/lib/stores.ts
@@ -1,14 +1,21 @@
 import { writable, get } from 'svelte/store';
 
 import mapboxgl from 'mapbox-gl';
-import { GPXFile, buildGPX, parseGPX } from 'gpx';
+import { GPXFile, GPXFiles, buildGPX, parseGPX } from 'gpx';
 
 export const map = writable<mapboxgl.Map | null>(null);
-export const files = writable<GPXFile[]>([]);
+export const fileCollection = writable<GPXFiles>(new GPXFiles([]));
 export const fileOrder = writable<GPXFile[]>([]);
 export const selectedFiles = writable<Set<GPXFile>>(new Set());
 export const selectFiles = writable<{ [key: string]: (file?: GPXFile) => void }>({});
 
+export function addFile(file: GPXFile) {
+    fileCollection.update($files => {
+        $files.files.push(file);
+        return $files;
+    });
+}
+
 export function triggerFileInput() {
     const input = document.createElement('input');
     input.type = 'file';
@@ -25,15 +32,15 @@ export function triggerFileInput() {
 
 export async function loadFiles(list: FileList) {
     for (let i = 0; i < list.length; i++) {
-        await loadFile(list[i]);
-        if (i == 0) {
-            get(selectFiles).select(get(files)[get(files).length - 1]);
+        let file = await loadFile(list[i]);
+        if (i == 0 && file) {
+            get(selectFiles).select(file);
         }
     }
 }
 
 export async function loadFile(file: File) {
-    let result = await new Promise<void>((resolve) => {
+    let result = await new Promise<GPXFile | null>((resolve) => {
         const reader = new FileReader();
         reader.onload = () => {
             let data = reader.result?.toString() ?? null;
@@ -42,9 +49,11 @@ export async function loadFile(file: File) {
                 if (gpx.metadata.name === undefined) {
                     gpx.metadata['name'] = file.name.split('.').slice(0, -1).join('.');
                 }
-                files.update($files => [...$files, gpx]);
+                addFile(gpx);
+                resolve(gpx);
+            } else {
+                resolve(null);
             }
-            resolve();
         };
         reader.readAsText(file);
     });
@@ -59,15 +68,15 @@ export function duplicateSelectedFiles() {
 
 export function duplicateFile(file: GPXFile) {
     let clone = file.clone();
-    files.update($files => [...$files, clone]);
+    addFile(clone);
 }
 
 export function removeSelectedFiles() {
     let index = 0;
-    while (index < get(files).length) {
-        if (get(selectedFiles).has(get(files)[index])) {
-            files.update($files => {
-                $files.splice(index, 1);
+    while (index < get(fileCollection).files.length) {
+        if (get(selectedFiles).has(get(fileCollection).files[index])) {
+            fileCollection.update($files => {
+                $files.files.splice(index, 1);
                 return $files;
             });
         } else {
@@ -78,8 +87,8 @@ export function removeSelectedFiles() {
 }
 
 export function removeAllFiles() {
-    files.update($files => {
-        $files.splice(0, $files.length);
+    fileCollection.update($files => {
+        $files.files.splice(0, $files.files.length);
         return $files;
     });
     get(selectedFiles).clear();
@@ -90,8 +99,8 @@ export function exportSelectedFiles() {
 }
 
 export async function exportAllFiles() {
-    for (let i = 0; i < get(files).length; i++) {
-        exportFile(get(files)[i]);
+    for (let file of get(fileCollection).files) {
+        exportFile(file);
         await new Promise(resolve => setTimeout(resolve, 200));
     }
 }