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KoalaSync Help & Troubleshooting
Start with the problem or question you have. These guides cover invites, browser access, video detection, encrypted chat, playback synchronization, supported devices, privacy, and release verification.
Choose a help topic
Playback & chat
Fix the selected player, room chat, or synchronization.
Using KoalaSync
Understand what the extension does and supports.
Privacy & trust
See what is shared and how official builds are verified.
The invite opens, but nothing happens
- 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.
- If you installed, enabled, or updated KoalaSync after opening the invite, reload the invite page once so the extension can connect to it.
- 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. - 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. - 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.
The extension must be detected on the invite page.
If the page still offers an install button even though KoalaSync is installed, the usual causes are a different browser profile, blocked website access, or a page that was opened before the extension became available.
The video tab does not appear
- Keep the video page open and reload it once.
- Close and reopen the KoalaSync popup, then check Select Video again.
- Open KoalaSync Settings and turn off Hide Clutter Tabs.
- Return to the tab selector. If the tab now appears, the site was filtered as clutter by mistake.
- If the tab is still missing, verify website access using the site-access guide.
Tell us which domain was classified incorrectly.
For a false clutter match, report the domain, whether the tab appears with the filter disabled, and whether the page contains a visible HTML5 video. A domain such as video.example.com is usually enough; do not publish a private URL containing account or session details.
The tab appears, but KoalaSync finds no usable video
- 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.
Chat does not work, or one person cannot see it
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. Older versions can still join a room and synchronize playback, but they do not support room chat.
- 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.
- 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.
- 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.
- 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. - 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.
Chat is live only.
There is no server-side message history. Someone who joins later sees only messages sent after they joined. Keep the invite link private: it contains the chat secret used to decrypt messages in that room.
Everyone is connected, but playback does not sync
- Update KoalaSync in every browser and confirm everyone uses the same extension version.
- Make sure each participant selected the correct local video tab.
- Reload the video page after changing website access, then select the tab again.
- Test play, pause, and seeking separately and note which action fails.
- Before anyone leaves the room, collect a debug report from every affected participant.
Does KoalaSync send the video to my friends?
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.
Which devices and browsers are supported?
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.
- Website compatibility depends on the browser and the site's video player. Websites can change their players, DRM behavior, or browser restrictions at any time.
- Protected, customized, or non-HTML5 players may need site-specific support even in a supported browser.
Why does the browser show such a broad warning?
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.
What data leaves my browser?
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.
Why should I trust KoalaSync?
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.
Advanced: verify signed build provenance
Install the GitHub CLI, download the release ZIP, and run:
gh attestation verify koalasync-chrome.zip \
--repo Shik3i/KoalaSyncTo verify the current Docker image:
gh attestation verify oci://ghcr.io/shik3i/koalasync:latest \
--repo Shik3i/KoalaSync
What an attestation proves, and what it does not.
An attestation proves the origin and build workflow of the GitHub release ZIP or GHCR image with that exact digest. It does not guarantee that software has no bugs or vulnerabilities. It also does not by itself prove that a package downloaded from a browser store is byte-for-byte identical to a GitHub release ZIP.
Create a useful GitHub issue
- Open KoalaSync, switch to Status, and click Copy Logs while the problem is still visible.
- Open the KoalaSync GitHub bug-report form and sign in to GitHub if requested.
- Describe the exact steps that reproduce the problem, what you expected, and what happened instead.
- Add your browser, operating system, KoalaSync version, and the affected website or domain.
- Paste the debug report, add a screenshot if useful, and review everything before publishing.
GitHub issues are public.
The copied report can include page titles and URLs, peer and room identifiers, participant names, and a custom server URL. Remove anything private. Never publish an invite link, room password, chat secret, account token, or a URL containing private session parameters.