Difference between "html.parser" vs "lxml"

1.     html.parser - BeautifulSoup(htmlmarkup, "html.parser")

• Advantages: 
• Batteries included
• Decent speed
• Built-in - no extra dependencies needed
• Lenient (as of Python 2.7.3 and 3.2.)
• Disadvantages: Not very lenient (before Python 2.7.3 or 3.2.2)

2.     lxml - BeautifulSoup(htmlmarkup, "lxml")

• Advantages: 
• Batteries included
• Very fast
• Lenient
• Works well when webpage has broken HTML
• Disadvantages: External C dependency

Documentation clearly mentioned. check this url here