The 828-meter (2,717-foot) Burj Khalifa in Dubai, United Arab Emirates, is the highest man-made skyscraper in the world. On January 9, 2010, the skyscraper officially opened and was dubbed the "tallest building in the world" and the tallest self-supported construction. The Tokyo Skytree, at 634 meters (2,080 feet) tall, is the world's tallest skyscraper. The second-tallest structure in the world is the 679-meter-tall (2,227-foot) Merdeka 118 in Kuala Lumpur, Malaysia. United States, is the tallest guyed structure, standing at 630 meters (2,060 feet).

the meaning of a tower, a building, and a structure
whether an official opening is required before a structure, building, or tower is assessed; if a structure, building, or tower that is still under construction should be included in any assessment; and whether structures that are built in and rising above water should have their below-water height included in any evaluation.
if a guyed building, structure, or tower is evaluated in the same class as self-supporting structures.
Within the recognized concept of a building, the following elements have generated additional debate:
If a structure is solely deemed habitable based on its height, could communication towers including observation galleries be classified as "habitable" in this context? What about rooftop antennas, viewing platforms, or any other architectural features that do not constitute a habitable space

The Burj Khalifa, a skyscraper in Dubai, is the highest artificial structure. Its height reached 829.8 meters (2,722 feet) on January 17, 2009.[2] It was constructed higher by April 8, 2008, than the KVLY-TV mast in North Dakota, USA.In September of that year, it officially overtook Poland's Warsaw radio mast, which stood at 646.38 meters (2,120.7 feet) from 1974 until 1991, to hold the title of highest building ever constructed. Since 1954, gauyed lattice towers, including these masts, have been the world record holder for height.
With its height of 610 meters (2,000 feet) above the ocean surface, the Petronius Platform held the title of the world's highest freestanding building until the Burj Khalifa overtook it in 2010. This was confirmed by Guinness World Records in 2007. But there is disagreement over whether underwater

When Taipei 101 in Taipei, Taiwan, first completed in 2004, it broke records in three of the four skyscraper categories. The Burj Khalifa, which debuted in 2010, was still the world's tallest inhabited structure at 509.2 m (1,671 ft) measured by its architectural height (spire). The Shanghai World Financial Center, with heights of 487 and 474 m (1,598 and 1,555 ft), had eclipsed its top at 449.2 m (1,474 ft) and highest inhabited floor at 439.2 m (1,441 ft). At 527 meters (1,729 feet), Willis Tower (previously Sears Tower) held the record for the highest skyscraper in the world from the top of its antenna.
The Burj Khalifa shattered all four height records.