1. Copy & paste the Youtube URL into the Source textbox
2. Set the starting point of Box A a few seconds ahead of Box B
3. Press Unlag! to start the video
4. Mute audio from Box A
5. You may need to adjust the starting point of Box A to get the optimal experience (repeat steps 2 to 4)

1. Copy & paste the Youtube URL into the Source textbox
2. Set the starting point of Box B a few seconds ahead of Box A
3. Press Unlag! to start the Box
4. Mute audio from Box A
5. You may need to adjust the starting point of Box B to get the optimal experience (repeat steps 2 to 4)

Although YoutubeUnlagger corrects audio synchronisation based on your input, the optimal result depends on the browser that you use. For instance, if the starting points for Boxes A and B are set to 0 seconds and 2 seconds:

• Firefox, Google Chrome and Apple Safari browsers - Video B almost always starts at 2.5 seconds
• Opera browser - Video B almost always starts at 2 seconds
• Internet Explorer - The performance is very unpredictable. Video B sometimes starts 2 seconds ahead or behind of Video A

Based on the findings made, we recommend that if you want to start Box A or Box B video half a second early or late, using Firefox, Google Chrome or Safari would probably give the best result. However, if you want to adjust videoplay exactly by the second, Opera browser is the way to go.

The performance difference is not something YoutubeUnlagger has deliberately introduced. Rather, it has to do with javascript interpretation which is different between browsers.

Technically, this is not possible as YoutubeUnlagger is limited by Youtube's API parameters. However, due to javascript performance issue, you can possibly do that by playing the videos through either Firefox, Google Chrome or Safari. See "How do I get the best experience?" under FAQs.

There are several possible reasons to this issue:

• "http://" may have been omitted - Check that in the source textfield that "http://" is present in front of www.youtube.com/...
• A non Youtube video has been loaded - YoutubeUnlagger only supports Youtube videos. Support for non-Youtube videos may be included in future development
• If you still can't get your video to play, drop us an e-mail at webmaster [at] youtubeunlagger.com

YoutubeUnlagger will solely be an advertisement-supported service. No plans for premium version are in line.