There are too many records and disputes.
There might have been a record on the largest anaconda ever, but it is continuously disputed. This is because people claim that they have seen something bigger. There are also different criteria to be considered. Some anacondas that were captured went as long as 28 feet with a girth of 44 inches, but were not the heaviest on record. There was another anaconda caught weighing over 500 pounds. There were even some claims that they have seen anacondas that are as large as human beings. There may or may not be true. Hence, the scientific community will always take these claims with a grain of salt.