Video Timeline Marker for YouTube & Twitch by ErttyOuO

For video editors, highlight editors, stream clip organizers, and anyone who needs to record timestamps while watching videos.

While watching YouTube or Twitch, you often find a moment you want to clip, revisit, organize, or add notes to later. Video Timeline Marker for YouTube & Twitch saves you from opening a notepad and copying times by hand: press the 🔖 marker button on the playback page and the current timestamp and video details are saved instantly.

One click to record

The marker is created the instant you press the button. There is no second save step. The button appears in the channel row (next to Subscribe) and in the player control bar, and in the top-right corner in fullscreen. You can also add a marker for the currently playing video directly from the toolbar popup.

When the marker panel opens, the cursor jumps into the note field so you can start typing right away. Notes are saved automatically when you stop typing.

Fast keyboard workflow

• Enter: confirm and close the marker panel
• Shift + Enter: insert a new line in the note
• +: move the current marker +5 seconds
• -: move the current marker -5 seconds

The + / - shortcuts also work while the note field is focused. While you compose text with an IME (Chinese, Japanese, etc.), Enter is not intercepted during composition.

Twitch VODs use the player's actual playback time. For Twitch live streams, the extension calibrates from the stream's elapsed time shown on the page together with relative changes in player time, and shows the calibration status.

Timeline list

Markers for the same video or stream are automatically sorted along the media's own timeline, earliest first. Even if you jump around and create markers in a different order, you still get a clear, time-ordered list that is ready for editing work.

The popup groups markers by video or stream and supports exporting or deleting a single marker, a whole video, a batch, or everything. Deleting shows a confirmation dialog; for a single marker, it auto-confirms after 1 second of inactivity, and moving your mouse into the dialog pauses it so you can choose to keep the marker.

TXT export and import

• Export a single marker
• Export all markers of one video or stream
• Select several videos for batch export
• Export all markers
• Re-import TXT files exported by this extension, including the older format

Each video or stream produces its own separate TXT file, so markers from different videos are never mixed in one file.

Optional Google Drive sync

If you use several devices, you can choose to connect Google Drive so markers sync in both directions.

• Entirely optional and off by default. Every feature works without it.
• Requests only the drive.appdata scope. Data is stored in the hidden application-data folder of your own Google Drive, and the extension cannot access any other file in your Drive.
• Local first: adding or editing a marker never waits for the network.
• Deletions sync too, so deleted markers do not come back on another device.
• You can disconnect at any time from the popup. Disconnecting does not delete your local markers.

Privacy first

By default, all markers and notes are stored only in Firefox's local browser.storage.local.

Only after you actively connect Google Drive and complete Firefox and Google authorization is marker data sent to your own Google Drive. The extension has no developer-operated server, so the developer cannot access your sync data. It uses no analytics, telemetry, advertising SDK, or trackers, and does not sell or share any data.

Full privacy policy: https://github.com/ErttyOuO/video-timeline-marker-firefox/blob/main/PRIVACY_POLICY.md

Permissions

• Storage: keeps markers, notes, and sync settings locally.
• Downloads: used only when you actively export a TXT file.
• YouTube / Twitch site access: reads the information needed from playback pages (title, channel or streamer name, URL, and current playback time) and adds the marker interface to the page.
• Identity: used only when you connect Google Drive, for the Google sign-in authorization flow.
• Alarms: schedules low-frequency automatic sync (about every 15 minutes).
• Scripting: used only when you press "Add marker" in the popup on a tab that has not yet loaded the extension; it re-injects the extension's own bundled files.
• WebNavigation: used temporarily, only in a compatibility sign-in flow for certain Firefox-based browsers; it is not used to monitor general browsing.
• www.googleapis.com / oauth2.googleapis.com: used only after you enable Google Drive sync, for the Drive API and OAuth.

Current limitations

• The dedicated YouTube Shorts player interface is not supported.
• Twitch live streams use page-time calibration, which differs from VODs that use the player time directly.
• Twitch OAuth / Helix API is not used yet, so live markers are not automatically matched to the VOD created after the stream ends.
• This is an independent tool and is not officially affiliated with or endorsed by YouTube, Google, or Twitch.