AB Loop Player

© 2016–2026 Alexander Grahn

A media player based on HTML5, jQuery UI and JavaScript, with A-B repeat, fast/slow motion and bookmarking functionality for online video (YouTube) and local video and audio files in various formats: MP4/H.264, WebM, Ogg, MP3, AAC, FLAC, WAV.

Firefox or Chrome on a Laptop or PC recommended.

Features:

• The A-B loop window can be adjusted with a double-handled slider, by pressing <kbd>←</kbd> & <kbd>→</kbd> on the keyboard, or, more accurately, via two time input fields. Loop quantisation (self-adjustment of the loop length) for music sequences is also available. The tempo needs to be tapped or entered via context menu beforehand. Suggestion by P. Jänis (@pjanis).
• The entire A-B loop window can be moved by pressing <kbd>Ctrl</kbd> while moving one of the slider handles with the mouse or the arrow keys.
• Additional means for modifying loop duration and position are provided through buttons <kbd>«</kbd> <kbd>×½</kbd> <kbd>×2</kbd> <kbd>»</kbd>; contributed by P. Jänis (@pjanis).
• A-B loops can be saved as bookmarks for the current and for later sessions.
• Bookmarked A-B loops can be annotated individually with short description texts.
• Share player link with the current YouTube video or playlist, loop settings and playback rate using <kbd><img src="https://agrahn.gitlab.io/ABLoopPlayer/svg/share.svg" width="16px"/></kbd>.
• Bookmarks and player settings can be exported and transferred between computers and different web browsers with buttons <kbd><img src="https://agrahn.gitlab.io/ABLoopPlayer/svg/export.svg" width="16px"/></kbd> and <kbd><img src="https://agrahn.gitlab.io/ABLoopPlayer/svg/import.svg" width="16px"/></kbd>.
• Playback rates from slow to fast motion
• Resizable video display

Usage (recommended): Use it online on GitLab or GitHub Pages: Paste in a valid YouTube URL, video or playlist ID, or browse the hard disk for video/audio files in one of the supported formats.

Installation (optional): Download from GitLab and unzip the archive file. Open ABLoopPlayer.html in the browser. Note that some YT content may not be playable if ABLoopPlayer.html is installed locally on a computer or on a web server outside the U.S.