★Download YouTube Videos Without Install Any Software

follow these steps:

• Go to YouTube home.
• Select your videos that you want to download.
• Copy URL of this videos:

www.youtube.com/watch?v=QcIy9NiNbmo

• Add " ss "  before youtube in above URL:

www.ssyoutube.com/watch?v=QcIy9NiNbmo

• press enter.

• Now, you can download your selected video in 720p, 320p, etc.

or

• You can in screenshot-you can also Download Extension in browser. 
• Even you can download this video in IDM:

  Download Internet Download manager(IDM pre-activated)