diff --git a/README.md b/README.md
index 29e0e199..47333a37 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,8 @@
 [Help translate Materialious!](https://fink.inlang.com/github.com/WardPearce/Materialious)
 
 # Features
+- [Syncios integration!](https://github.com/WardPearce/syncious)
+  - Sync your watch progress between Invidious sessions.
 - Watch sync parties!
 - Sponsorblock built-in.
 - Return YouTube dislikes built-in.
@@ -247,7 +249,30 @@ http:
 ### Step 3:
 Modify/add `VITE_DEFAULT_RETURNYTDISLIKES_INSTANCE` for Materialious to be the reverse proxied URL of RYD-Proxy.
 
-## Step 5 (Optional): Self-host PeerJS
+## Step 5 (Optional, but recommended): Self-host Syncios
+Sync your watch progress between Invidious sessions.
+
+### Step 1: Docker compose
+Add the following to your docker compose
+
+```yaml
+services:
+  syncious:
+    image: wardpearce/syncious:latest
+    restart: unless-stopped
+    ports:
+      - 3004:80
+    environment:
+      syncious_postgre: '{"host": "invidious-db", "port": 5432, "database": "invidious", "user": "kemal", "password": "kemal"}'
+      syncious_allowed_origins: '["https://materialios.example.com"]'
+      syncious_debug: false
+
+      # No trailing backslashes!
+      syncious_invidious_instance: "https://invidious.example.com"
+      syncious_production_instance: "https://syncious.example.com"
+```
+
+## Step 6 (Optional): Self-host PeerJS
 [Read the official guide.](https://github.com/peers/peerjs-server?tab=readme-ov-file#docker)
 
 Add these additional environment variables to Materialious.
diff --git a/materialious/src/lib/Api/index.ts b/materialious/src/lib/Api/index.ts
index 277d0598..4d6fa107 100644
--- a/materialious/src/lib/Api/index.ts
+++ b/materialious/src/lib/Api/index.ts
@@ -3,7 +3,8 @@ import {
 	authStore,
 	deArrowInstanceStore,
 	deArrowThumbnailInstanceStore,
-	returnYTDislikesInstanceStore
+	returnYTDislikesInstanceStore,
+	synciousInstanceStore
 } from '../../store';
 import type {
 	Channel,
@@ -18,6 +19,7 @@ import type {
 	ReturnYTDislikes,
 	SearchSuggestion,
 	Subscription,
+	SynciousProgressModel,
 	Video,
 	VideoPlay
 } from './model';
@@ -301,3 +303,56 @@ export async function getThumbnail(videoId: string, time: number): Promise<strin
 	);
 	return URL.createObjectURL(await resp.blob());
 }
+
+export async function getVideoProgress(videoId: string): Promise<SynciousProgressModel[]> {
+	const resp = await fetchErrorHandle(
+		await fetch(
+			`${get(synciousInstanceStore)}/video/${encodeURIComponent(videoId)}`,
+			buildAuthHeaders()
+		)
+	);
+
+	return resp.json();
+}
+
+export async function saveVideoProgress(videoId: string, time: number) {
+	const headers: Record<string, Record<string, string>> = buildAuthHeaders();
+	headers['headers']['Content-type'] = 'application/json';
+
+	await fetchErrorHandle(
+		await fetch(
+			`${get(synciousInstanceStore)}/video/${encodeURIComponent(videoId)}`,
+			{
+				...headers,
+				method: "POST",
+				body: JSON.stringify({
+					time: time
+				})
+			}
+		)
+	);
+}
+
+export async function deleteVideoProgress(videoId: string) {
+	await fetchErrorHandle(
+		await fetch(
+			`${get(synciousInstanceStore)}/video/${videoId}`,
+			{
+				method: "DELETE",
+				...buildAuthHeaders()
+			}
+		)
+	);
+}
+
+export async function deleteAllVideoProgress() {
+	await fetchErrorHandle(
+		await fetch(
+			`${get(synciousInstanceStore)}/videos`,
+			{
+				method: "DELETE",
+				...buildAuthHeaders()
+			}
+		)
+	);
+}
\ No newline at end of file
diff --git a/materialious/src/lib/Api/model.ts b/materialious/src/lib/Api/model.ts
index dd1604b7..6fe6552f 100644
--- a/materialious/src/lib/Api/model.ts
+++ b/materialious/src/lib/Api/model.ts
@@ -250,3 +250,12 @@ export interface DeArrow {
 	randomTime: number;
 	videoDuration: number;
 }
+
+export interface SynciousProgressModel {
+	time: number;
+	video_id: string;
+}
+
+export interface SynciousSaveProgressModel {
+	time: number;
+}
diff --git a/materialious/src/lib/Player.svelte b/materialious/src/lib/Player.svelte
index 3be87ae7..a39784b8 100644
--- a/materialious/src/lib/Player.svelte
+++ b/materialious/src/lib/Player.svelte
@@ -8,14 +8,17 @@
 	import type { MediaTimeUpdateEvent, PlayerSrc } from 'vidstack';
 	import type { MediaPlayerElement } from 'vidstack/elements';
 	import {
+		authStore,
 		playerAlwaysLoopStore,
 		playerAutoPlayStore,
 		playerDashStore,
 		playerProxyVideosStore,
 		playerSavePlaybackPositionStore,
 		sponsorBlockCategoriesStore,
-		sponsorBlockUrlStore
+		sponsorBlockUrlStore,
+		synciousStore
 	} from '../store';
+	import { deleteVideoProgress, getVideoProgress, saveVideoProgress } from './Api';
 	import type { VideoPlay } from './Api/model';
 	import { getBestThumbnail, proxyVideoUrl, videoLength, type PhasedDescription } from './misc';
 	import { getDynamicTheme } from './theme';
@@ -114,8 +117,8 @@
 			}
 
 			if (get(playerDashStore)) {
-				player.addEventListener('dash-can-play', () => {
-					loadPlayerPos();
+				player.addEventListener('dash-can-play', async () => {
+					await loadPlayerPos();
 				});
 
 				src = [{ src: data.video.dashUrl + '?local=true', type: 'application/dash+xml' }];
@@ -180,31 +183,47 @@
 		document.documentElement.style.setProperty('--audio-bg', currentTheme['--surface']);
 	});
 
-	function loadPlayerPos() {
+	async function loadPlayerPos() {
 		if (playerPosSet) return;
 		playerPosSet = true;
 		if (get(playerSavePlaybackPositionStore)) {
-			try {
-				const playerPos = localStorage.getItem(`v_${data.video.videoId}`);
-				if (playerPos) {
-					player.currentTime = Number(playerPos);
-				}
-			} catch {}
+			if (get(synciousStore) && get(authStore)) {
+				try {
+					player.currentTime = (await getVideoProgress(data.video.videoId))[0].time;
+				} catch {}
+			} else {
+				try {
+					const playerPos = localStorage.getItem(`v_${data.video.videoId}`);
+					if (playerPos) {
+						player.currentTime = Number(playerPos);
+					}
+				} catch {}
+			}
 		}
 	}
 
 	function savePlayerPos() {
 		if (data.video.hlsUrl) return;
 
-		try {
-			if (get(playerSavePlaybackPositionStore) && player.currentTime) {
-				if (player.currentTime < player.duration - 10 && player.currentTime > 10) {
+		if (get(playerSavePlaybackPositionStore) && player.currentTime) {
+			if (player.currentTime < player.duration - 10 && player.currentTime > 10) {
+				try {
 					localStorage.setItem(`v_${data.video.videoId}`, player.currentTime.toString());
-				} else {
+				} catch {}
+
+				if (get(synciousStore) && get(authStore)) {
+					saveVideoProgress(data.video.videoId, player.currentTime);
+				}
+			} else {
+				try {
 					localStorage.removeItem(`v_${data.video.videoId}`);
+				} catch {}
+
+				if (get(synciousStore) && get(authStore)) {
+					deleteVideoProgress(data.video.videoId);
 				}
 			}
-		} catch {}
+		}
 	}
 
 	onDestroy(() => {
diff --git a/materialious/src/lib/Thumbnail.svelte b/materialious/src/lib/Thumbnail.svelte
index c80b1ca5..311edadd 100644
--- a/materialious/src/lib/Thumbnail.svelte
+++ b/materialious/src/lib/Thumbnail.svelte
@@ -3,14 +3,16 @@
 	import { _ } from 'svelte-i18n';
 	import { get } from 'svelte/store';
 	import {
+		authStore,
 		deArrowEnabledStore,
 		interfacePreviewVideoOnHoverStore,
 		playerProxyVideosStore,
 		playerSavePlaybackPositionStore,
 		syncPartyConnectionsStore,
-		syncPartyPeerStore
+		syncPartyPeerStore,
+		synciousStore
 	} from '../store';
-	import { getDeArrow, getThumbnail, getVideo } from './Api';
+	import { getDeArrow, getThumbnail, getVideo, getVideoProgress } from './Api';
 	import type { Notification, PlaylistPageVideo, Video, VideoBase, VideoPlay } from './Api/model';
 	import { cleanNumber, getBestThumbnail, proxyVideoUrl, videoLength } from './misc';
 	import type { PlayerEvents } from './player';
@@ -128,6 +130,12 @@
 		img.onerror = () => {
 			loading = false;
 		};
+
+		if (get(synciousStore) && get(authStore)) {
+			try {
+				progress = (await getVideoProgress(video.videoId))[0].time.toString();
+			} catch {}
+		}
 	});
 
 	function syncChangeVideo() {
diff --git a/materialious/src/routes/+layout.svelte b/materialious/src/routes/+layout.svelte
index 4752fb0f..cf5791bd 100644
--- a/materialious/src/routes/+layout.svelte
+++ b/materialious/src/routes/+layout.svelte
@@ -42,6 +42,8 @@
 		sponsorBlockUrlStore,
 		syncPartyConnectionsStore,
 		syncPartyPeerStore,
+		synciousInstanceStore,
+		synciousStore,
 		themeColorStore
 	} from '../store';
 
@@ -61,6 +63,7 @@
 	let notifications: Notification[] = [];
 
 	let sponsorBlockInstance = get(sponsorBlockUrlStore);
+	let synciousInstance = get(synciousInstanceStore);
 	let returnYTInstance = get(returnYTDislikesInstanceStore);
 	let deArrowUrl = get(deArrowInstanceStore);
 	let deArrowThumbnailUrl = get(deArrowThumbnailInstanceStore);
@@ -604,6 +607,36 @@
 		</nav>
 	</div>
 
+	<div class="settings">
+		<h6>Syncious</h6>
+
+		<form on:submit|preventDefault={() => synciousInstanceStore.set(synciousInstance)}>
+			<nav>
+				<div class="field label border max">
+					<input bind:value={synciousInstance} name="syncious-instance" type="text" />
+					<label for="syncious-instance">{$_('layout.instanceUrl')}</label>
+				</div>
+				<button class="square round">
+					<i>done</i>
+				</button>
+			</nav>
+		</form>
+
+		<nav class="no-padding">
+			<div class="max">
+				<p>{$_('enabled')}</p>
+			</div>
+			<label class="switch">
+				<input
+					bind:checked={$synciousStore}
+					on:click={() => synciousStore.set(!$synciousStore)}
+					type="checkbox"
+				/>
+				<span></span>
+			</label>
+		</nav>
+	</div>
+
 	<div class="settings">
 		<h6>Sponsorblock</h6>
 
diff --git a/materialious/src/routes/history/+page.svelte b/materialious/src/routes/history/+page.svelte
index f25a721b..eaa5b567 100644
--- a/materialious/src/routes/history/+page.svelte
+++ b/materialious/src/routes/history/+page.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { deleteHistory, getHistory, getVideo } from '$lib/Api';
+	import { deleteAllVideoProgress, deleteHistory, getHistory, getVideo } from '$lib/Api';
 	import type { VideoPlay } from '$lib/Api/model';
 	import PageLoading from '$lib/PageLoading.svelte';
 	import VideoList from '$lib/VideoList.svelte';
@@ -7,7 +7,8 @@
 	import { onMount } from 'svelte';
 	import { _ } from 'svelte-i18n';
 	import InfiniteLoading, { type InfiniteEvent } from 'svelte-infinite-loading';
-	import { activePageStore } from '../../store';
+	import { get } from 'svelte/store';
+	import { activePageStore, synciousStore } from '../../store';
 
 	activePageStore.set('history');
 
@@ -62,6 +63,11 @@
 	<button
 		on:click={async () => {
 			await deleteHistory();
+
+			if (get(synciousStore)) {
+				deleteAllVideoProgress();
+			}
+
 			history = [];
 			try {
 				Object.keys(localStorage).forEach((key) => {
diff --git a/materialious/src/store.ts b/materialious/src/store.ts
index ff329409..7d2f5dd1 100644
--- a/materialious/src/store.ts
+++ b/materialious/src/store.ts
@@ -3,10 +3,12 @@ import type { DataConnection } from 'peerjs';
 import { persisted } from 'svelte-persisted-store';
 import { writable, type Writable } from 'svelte/store';
 
-export const returnYTDislikesInstanceStore: Writable<string | null | undefined> = persisted(
-	'returnYTDislikesInstance',
-	import.meta.env.VITE_DEFAULT_RETURNYTDISLIKES_INSTANCE
+export const authStore: Writable<null | { username: string; token: string; }> = persisted(
+	'authToken',
+	null
 );
+
+
 export const darkModeStore: Writable<null | boolean> = persisted('darkMode', null);
 export const themeColorStore: Writable<null | string> = persisted('themeColor', null);
 
@@ -22,15 +24,20 @@ export const playerTheatreModeByDefaultStore = persisted('theatreModeByDefault',
 export const playerAutoplayNextByDefaultStore = persisted('autoplayNextByDefault', false);
 
 export const returnYtDislikesStore = persisted('returnYtDislikes', false);
+export const returnYTDislikesInstanceStore: Writable<string | null | undefined> = persisted(
+	'returnYTDislikesInstance',
+	import.meta.env.VITE_DEFAULT_RETURNYTDISLIKES_INSTANCE
+);
+
+export const synciousStore = persisted('syncious', true);
+export const synciousInstanceStore: Writable<string | null | undefined> = persisted(
+	'synciousInstance',
+	import.meta.env.VITE_DEFAULT_SYNCIOUS_INSTANCE
+);
 
 export const interfaceSearchSuggestionsStore = persisted('searchSuggestions', true);
 export const interfacePreviewVideoOnHoverStore = persisted('previewVideoOnHover', true);
 
-export const authStore: Writable<null | { username: string; token: string; }> = persisted(
-	'authToken',
-	null
-);
-
 export const sponsorBlockStore = persisted('sponsorBlock', true);
 export const sponsorBlockUrlStore: Writable<string | null | undefined> = persisted(
 	'sponsorBlockUrl',