KoalaSync Help & Troubleshooting

The person who created the room is the host. Under Room → Host Control, the host can enable Only I can control playback. The host can then use Give control beside individual participants to make them controllers, and Revoke to remove that role.

• Hosts and granted controllers can move the shared room with play, pause, seek, Force Sync, and episode-lobby actions.
• A guest action that conflicts with Host Control may briefly affect only that guest's local player before KoalaSync restores the shared state.
• A guest can choose Watch on my own to enter Solo mode. Host commands are then ignored locally until the guest clicks Resync.
• If the host leaves while others remain, another participant becomes host and control returns to everyone.

Auto-Sync Next Episode is enabled by default under Settings → Playback & Sync. On supported sites, KoalaSync detects a recognizable episode change, pauses, and opens an Episode Lobby while participants load the same episode. Playback starts together when the lobby is ready.

• Use Skip & Play anyway if you do not want to wait.
• A timeout or participants leaving can cancel the lobby; use manual selection and Force Sync afterward.
• The feature depends on usable episode titles. It is not available for ordinary single videos, and some services expose too little episode information.
• Choosing Do not send for media titles prevents creation of an episode lobby. Send episode ID can preserve episode matching without sharing the full media title when an episode ID is detectable.

Open Settings → Playback & Sync → Audio Processing. Enable Audio Processing and the compressor, then start with a preset such as Recommended, Dynamic Range, Vocal Enhancement, or Smooth. Selecting Custom exposes the compressor controls.

• Audio Processing affects only your selected video in your browser. It is not shared or synchronized with the room.
• It changes audio dynamics, not the room's playback timing.
• The Equalizer is marked Coming soon and is not currently available.
• If a site replaces its player or audio stops behaving normally, reload the page and reselect the tab; disable Audio Processing to compare.

1. Open the invite in the same desktop browser profile where KoalaSync is installed. Extensions installed in another browser or profile cannot receive the join request.
2. If you installed, enabled, or updated KoalaSync after opening the invite, reload the invite page once so the extension can connect to it.
3. Confirm that KoalaSync is allowed to run on sync.koalastuff.net. If the browser blocks access, follow the site-access guide, then reload the invite.
4. Ask the sender to open KoalaSync and copy the invite link again. Use the complete link without removing anything after #; that part contains the room credentials and current chat secret.
5. Wait for the join page to report success. Joining the room does not select a video automatically, so open KoalaSync afterward and choose your local video tab under Sync.

1. Keep the video page open and reload it once.
2. Close and reopen the KoalaSync popup, then check Select Video again.
3. Open KoalaSync Settings and turn off Hide Clutter Tabs.
4. Return to the tab selector. If the tab now appears, the site was filtered as clutter by mistake.
5. If the tab is still missing, verify website access using the site-access guide.

• Select the exact tab containing the visible player, not a login, search, or media-library tab.
• Start the video once. Some websites create their video element only after playback begins.
• Open the KoalaSync Status tab and inspect Video Debug Info.
• If the report says NO VIDEO ELEMENT, note the video count and whether Shadow DOM was detected.
• Temporarily disable other extensions that modify the player, then reload and test again.
• Protected, heavily customized, or non-HTML5 players may require site-specific support.

Room chat was introduced in KoalaSync 3.0.0. Every participant who wants to send or read chat messages needs version 3.0.0 or newer. Supported pre-3.0 versions may still synchronize playback, but they do not support room chat.

Chat is optional and appears on the selected video page. Under Settings → Room Chat, you can start it as a floating bubble or open overlay, dock it left or right, detach it, choose its size, control chat notifications, and keep quick reactions in chat or also show them over the video.

1. Update KoalaSync in every browser. Open the extension and check the version in the top-right corner. Each participant needs version 3.0.0 or newer.
2. After updating, the room creator should leave the old room and click Create New Room. This creates a new chat encryption secret and includes it in the new invite link.
3. Send that newly copied invite link to your friends. Each friend must leave the old room and join through the link so their extension receives the same chat encryption secret.
4. Do not join by typing only the room ID and password, and do not reuse an old invite link beginning with #join:. Both can connect playback synchronization, but neither contains the chat secret.
5. Each participant must select their local video tab, then open Settings → Room Chat and turn on Enable Room Chat. The chat appears on the selected video page, not inside the extension popup.

Open Settings → Privacy. Tab titles and media titles have separate controls:

• Send tab title: shares or withholds the title shown by the selected browser tab.
• Send full title: shares the media title detected from the player.
• Send episode ID: shares only a detected identifier such as S01E04. If no episode ID can be detected, no useful full title is substituted.
• Do not send: withholds the media title.

Reducing title sharing can make automatic tab matching and episode coordination less informative. Disabling media-title sharing also prevents Auto-Sync Next Episode from creating a lobby.

KoalaSync uses the official relay by default. If you or someone you trust operates a compatible KoalaSync relay, open Room → Manual Connect / Advanced, choose Custom, enter its WebSocket URL, then join or create a room.

• Use a wss:// URL for a relay on the public internet. Plain ws:// is intended for local testing on localhost.
• All participants in a room must connect to the same relay. An invite created on a custom relay includes that relay address for current KoalaSync clients.
• The operator of a custom relay controls its hosting, logging, retention, updates, and availability. The official relay's privacy policy does not describe third-party instances.
• If the custom URL is rejected or the connection fails, confirm the complete WebSocket URL with its operator. A normal website URL is not always the relay URL.

See the self-hosting overview. Deployment instructions are intended for the person operating the server; ordinary participants only need the supplied relay URL.

1. Make sure everyone uses a currently supported KoalaSync version. Different supported versions can work together, but optional features may not be available to everyone.
2. Make sure each participant selected the correct local video tab.
3. Reload the video page after changing website access, then select the tab again.
4. Test play, pause, and seeking separately and note which action fails.
5. If the Status tab says Disconnected or Failed, click Retry. For a custom relay, confirm its URL and availability with the operator.
6. If KoalaSync reports Duplicate Identity, open Settings → Troubleshooting and click Regenerate Peer ID.
7. Before anyone leaves the room, collect a debug report from every affected participant.

No. KoalaSync does not stream, upload, proxy, download, or redistribute video content. It only sends the live room and playback events needed to keep actions such as play, pause, and seeking synchronized.

• Everyone watches the video locally in their own browser on the original website.
• Each participant needs their own valid access to the website or streaming service.
• KoalaSync does not bypass subscriptions, logins, DRM, regional restrictions, or platform rules.
• Subtitles, audio tracks, fullscreen, and video quality remain local choices when the video player supports them.

KoalaSync is currently a desktop browser extension. It supports Google Chrome, Mozilla Firefox, Microsoft Edge, Opera, Brave, Vivaldi, and other compatible Chromium-based desktop browsers on Windows, macOS, Linux, and ChromeOS.

• There is currently no KoalaSync mobile app for phones or tablets.
• There is currently no Safari extension.
• KoalaSync targets visible HTML5 video players. Protected, customized, cross-origin, or non-HTML5 players may expose only part of the information or controls KoalaSync needs.
• The project's compatibility matrix currently lists playback sync as working for YouTube, Twitch, Netflix, Emby, Jellyfin, Disney+, Prime Video, and Vix. These project records are not a compatibility guarantee and do not currently include test dates or extension versions.
• Title and episode support varies: Netflix exposes no usable media title in the recorded tests; Disney+ exposes only a partial title; automatic episode sync is recorded for Emby, Jellyfin, and Vix.
• Plex, Max, Crunchyroll, Vimeo, Dailymotion, and ARD/ZDF are currently listed as not tested, not as supported or unsupported.
• Website compatibility can change when a service changes its player, DRM behavior, page structure, or browser restrictions.

View the current tested-services matrix

Browsers may say that KoalaSync can “read and change all your data on all websites.” The wording is broad because KoalaSync is designed to work with video players across many different websites instead of a short fixed list.

KoalaSync injects its synchronization script into the video tab you actively select. On that tab it needs to find and control the video element, synchronize play, pause, and seeking, and display the optional room chat overlay. Open tab titles are read to populate the tab selector. KoalaSync does not create a general browsing or watch history.

Read the complete permission and data-handling explanation

KoalaSync only connects to a relay while you are actively in a room. During that session, the relay temporarily processes the data required to connect participants and synchronize playback.

• Room and presence: room ID, peer ID, display name, connection state, and the information needed to join the room.
• Playback synchronization: actions and state such as play, pause, seeking, and the current playback position.
• Titles: tab or media titles may be shared with room participants depending on your title privacy settings. They can be limited or disabled.
• Room chat: message text is encrypted in the extension before transmission. The relay receives ciphertext and delivery metadata, but not the chat secret or readable message text.
• Stored locally: preferences, current room credentials, and the chat secret are stored in the browser. The chat secret is not sent to the relay. Decrypted chat entries remain only in the current page overlay and are not written to browser storage.
• Operational logs: the relay may log technical connection and security information such as IP addresses, protocol versions, socket or peer identifiers, and shortened room identifiers. Retention depends on the server infrastructure and configuration.

KoalaSync does not create a persistent browsing, room, synchronization, chat, or watch history. Browser or operating-system notifications may retain notification text according to their own settings.

Read the complete privacy policy

Trust should not depend on promises alone. The KoalaSync browser extension, relay server, build scripts, release workflow, and Dockerfile used for official GitHub releases are public under the MIT License.

Official extension ZIPs on GitHub Releases and Docker images on GitHub Container Registry are built by the public GitHub Actions release workflow. Signed SLSA provenance attestations connect each artifact's exact digest to this repository, its release tag and commit, and the workflow that built it.

You can install KoalaSync from an official browser store, download the Chrome or Firefox ZIP from GitHub Releases, build the extension yourself, or run your own relay server. Manual ZIP installation uses your browser's developer or manual extension installation process.

gh attestation verify koalasync-chrome.zip \
  --repo Shik3i/KoalaSync

gh attestation verify oci://ghcr.io/shik3i/koalasync:latest \
  --repo Shik3i/KoalaSync

1. Open KoalaSync and switch to Status while the problem is still visible. Check Connection Status, Video Debug Info, Full Action History, and the last 50 connection logs.
2. Click Copy Logs. The copied debug report combines the relevant status, room, participant, video, action, and log details for troubleshooting.
3. Open the KoalaSync GitHub bug-report form and sign in to GitHub if requested.
4. Describe the exact steps that reproduce the problem, what you expected, and what happened instead.
5. Add your browser, operating system, KoalaSync version, and the affected website or domain.
6. Paste the debug report, add a screenshot if useful, and review everything before publishing.