[8] Free Solo received acclaim from critics and numerous accolades, including winning Best Documentary Feature at the 91st Academy Awards.

[9][10] Climber Alex Honnold has been dreaming of free-soloing the 3,000 feet (900 m) rock wall of El Capitan in Yosemite National Park, a feat no one has performed.

In the fall of 2016, Alex sprains his ankle on El Capitan while traditional climbing (i.e., using ropes and protection equipment) on the first section of Freerider, the giant multi-pitch slab known as Freeblast and graded at 5.11b (6c).

Both the crew and Sanni suggest abandoning the plan, and Alex admits he does not want his friends to see him die if he falls while free soloing.

After giving up on his plan to free solo El Capitan that season, Alex and Sanni buy a house in Las Vegas.

Prior to filming, directors Elizabeth Chai Vasarhelyi and Jimmy Chin struggled with the ethical ramifications and decisions behind creating Free Solo, knowing Honnold could die on camera.

[11] Ultimately, they decided to go through with the film and devoted some time to documenting its own production process, with Chin and his camera crew discussing the challenge of not endangering climber Alex Honnold by distracting him or putting any pressure at all on him to attempt the climb.

[24] Peter Debruge of Variety praised the pacing of the film, saying: "Apart from a slow stretch around the hour mark, the filmmakers keep things lively (with a big assist from Marco Beltrami's pulse-quickening score, the nail-biting opposite of Tim McGraw's soaring end-credits single, "Gravity").

"[25] Richard Lawson of Vanity Fair called the film "bracingly made" and felt the filmmakers properly conveyed the challenges and dangers faced by Honnold in his endeavors: "Free Solo's detailed, transfixing portrait of their hero will at least show some sort of barrier to entry, communicating to those eager wannabes that very few people indeed are built quite like Alex Honnold.

"[26] Michael Hale of Sight and Sound praised the filming techniques and resulting effect, saying that an image reminiscent of Greek mythology is evoked as Honnold is captured scaling the immense wall of El Capitan.