Fluffy, a reticulated python (not an Anaconda!!) currently holds the Guinness record for being the longest snake at 24 ft. Although there have been claims of snakes being as big as 40 ft, but none have been verified. BTW there’s a 50,000$ prize for live delivery of any snake above 30ft. 
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[youtube=http://www.youtube.com/watch?v=hnqXoexJZjg&w=448&h=252&hd=1]
Fluffy
24 feet !!!!!!!!!!!! That’s like 2 floors : 0
lol yup!!! Shame its dead now. 🙁 Though there can be as long as 30 ft in the wild.