Free solo climbing, also known as Soloing, is a form of free climbing and solo climbing where the climber (or free soloist) performs alone and without using any ropes, harnesses or other protective equipment, relying entirely on his or her ability instead.
Unlike in bouldering, soloists typically climb above safe heights, where a fall would always result in serious injury or death.
In ordinary free climbing, safety gear is used to protect from falls, although not to assist the ascent.
Reasons for free soloing given by high-profile climbers include the simplicity and speed with which one can climb, for example Alex Honnold's two-hour-and-fifty-minute ascent of the 2,224-foot (678 m) Regular Northwest Face route on Yosemite's Half Dome, a route normally demanding multiple days.
The practice is mostly confined to routes familiar to the climber, whose difficulty lies well within the climber's abilities.
However, inherent risks such as loose rocks or sudden change in weather are always present.
Some high-profile climbers have died while free soloing, including John Bachar, Derek Hersey, Vik Hendrickson, Robert Steele, Dwight Bishop, Jimmy Ray Forrester, Jimmy Jewell, Tony Wilmott, and John Taylor.
The sport has produced a number of well-known practitioners, made famous by photos of a climber totally alone and unprotected on sheer cliffs.
Two of the most famous free soloists, Alain Robert ("The French Spider-Man"), and Dan Goodwin ("Skyscraperman"), have also scaled dozens of skyscrapers around the world — a sport known as buildering (not to be confused with bouldering) — without using any safety equipment.
In June 2017, Alex Honnold made international news with the first free-solo ascent of El Capitan in Yosemite, on a route rated 5.13a in the Yosemite Decimal System.
Some climbers who are known for their regular practice of free solo climbing include: Hansjörg Auer, John Bachar, Patrick Berhault, Thomas Bubendorfer, Matt Bush, Renaldo Clarke, Peter Croft, Steph Davis, Bill Denz, Tim Deroehn, Catherine Destivelle, Patrick Edlinger, Eric Escoffier, Dan Goodwin, Mike Graham, Wolfgang Güllich, Colin Haley, Derek Hersey, Alex Honnold, Alexander Huber, Jimmy Jewell, Eric Jones, Kevin Jorgeson, Ally Law, Matt Lloyd, Dave Mac Leod, Dan Osman, Dean Potter, Paul Preuss, Andreas Proft, Herbert Ranggetiner, Michael Reardon, Alain Robert, Tobin Sorenson, Will Stanhope, Ueli Steck, Slavko Svetičič, Miroslav Šmíd, Akihira Tawara, John Yablonski, Maurizio Zanolla, and Brad Gobright.
Some climbers who occasionally or rarely free solo climbed, but have been influential to the practice, include: Pierre Allain, Henry Barber, Lynn Hill, Ron Kauk, Jean-Christophe Lafaille, John Long, Dave Mac Leod and Reinhold Messner.