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Will Bosi

Known as the youngest Brit to climb 9a, Will Bosi is one of the most impressive and rapidly growing climbers of our time. Since breaking into the spotlight in 2018, he has dominated the IFSC competition circuit as well as having incredible achievements in climbing, becoming the first Brit to successfully finish a 9b+, King Capella and becoming the second person to climb the hardest boulder in the world, Burden of Dreams.


United Kingdom

Date Of Birth



Sport Climbing & Bouldering

Hardest Sport

9b+ (5.15c)

Hardest Boulder


Hardest Trad


Will Bosi

Ascent Log

ClimbTypeSuggested GradeDate of AscentNotes
Burden of DreamsBoulder9A/V1712th Apr 2023Will said BofD was a hard 9A/V17. Video and Instagram Post
AlphaneBoulder9A/V1731st Oct 2022A soft 9A boulder. Video and Instagram Post
Return of the SleepwalkerBoulder9A/V1720th Feb 2024Instagram Post
Honey BadgerBoulder8C+/V1610th Aug 2022Honey Badger felt harder than Alphane. Video
EphyraBoulder8C+/V168th Nov 2022Instagram Post and Video
Isles of Wonder SDSBoulder8C/V1521st May 2023Proposed a 8C rather than an 8C+. Video
Ulls de BruixaBoulder8C/V1511th Feb 2021Instagram Post and Video
BulbasaurBoulder8C/V157th Apr 2022Video
TranceBoulder8C/V159th Jun 2022Video
Beautiful MindBoulder8C/V1514th Jul 2022Video
The Wild SouthBoulder8C/V1526th Apr 2023Suggested it could be of an 8C+. Video
SerenataBoulder8C/V153rd Sep 2020Video
Foundations EdgeBoulder8C/V1523rd Sep 2021Climber Magazine
DriftBoulder8C/V1527th Mar 2022Video
Pata LedovceBoulder8C/V154th Apr 2022Video
Ghost RiderBoulder8C/V159th Apr 2022Instagram Post
Tekuté ŠtěstíBoulder8C/V1511th Apr 2022Video
IcebergBoulder8C/V1512th Apr 2022Video
Silent SingerBoulder8C/V156th Jun 2022Video
OutliersBoulder8C/V1512th Jun 2022Video
Forgotten GemBoulder8C/V156th Nov 2022Instagram Post
DreamtimeBoulder8C/V156th Dec 2022Video
Ultra InstinctBoulder8C/V158th Jun 2023Video
King CapellaSport Route9b9th Mar 2021FA. Bosi initially proposed a 9b+ grade but Megos and Schubert downgraded it to a 9b. Instagram Post and Video
La CapellaSport Route9b5th Feb 2020Second 9b by a British climber and first one for Will.
La Furia de JabaliSport Route9a+4th Feb 2021Will’s first FA. Instagram Post
Brandenburg GateSport Route9a+7th Nov 2021Video
Free at LastSport Route9a+25th Jun 2022Instagram Post
First LeySport Route9a+24th Feb 2021Video
MutationSport Route9a+Oct 2021First repeat after 23 years!

Kit Bag

Climbing Career

Learning the Ropes & Competition

In the heart of Edinburgh, Scotland, a six-year-old Will Bosi discovered a passion that would shape the trajectory of his life. Nestled in the shadows of the city’s craggy peaks, he and his brother embarked on a thrilling exploration of the vertical world. Will wasn’t just climbing; he was evolving into a phenomenon.

Will Bosi comp climbing
Will in his comp days ©Henning Schlottmann

By the ripe age of 14, his fingers had clenched the crags of 7c, 7c+, and even 8a grades.  Around the same time, he qualified for the Great Britain junior team and finished fourth in his first IFSC World Youth Championships in Singapore.

Bosi took first place on the podium at the European Youth Cup in 2013 with two silver medals in the lead and speed disciplines, as well as claiming his first 8a, 8b, and 8b+ successful climbs.

Outdoor Climbing

I think it’s fair to say that where Bosi has excelled is in his outdoor climbing. He began making a name for himself in the outdoor climbing world at the age of 16 in 2015, when he climbed his first 8b+ (V14) boulder, Monk Life, in North Eastern England. Later that year, Bosi set another milestone in his climbing career by becoming the youngest British climber to redpoint Steve McLure’s Rainshadow (9a), which was also his longest project at the time, taking him eight days to complete.

Five years later, after numerous accomplishments in his home country and abroad, Will made history by completing the fourth ascent of La Capella (9b), becoming only the second Brit to do so. Adam Ondra led the first ascent of the 15-meter-long route bolted in 1995 by David and Charles Brasco in 2011, followed by Stefano Ghisolfi and Daniel Woods.

Climber Will Bosi on  La Capella
Bosi making the fourth ascent of La Capella 9b

Despite his apparent focus on crushing the outside scene, Bossi did not ignore the IFSC circuit, making the finals in the majority of European and World championships in lead, bouldering, and speed. Will began preparing for the 2020 Tokyo Olympics, which were unfortunately postponed due to the COVID pandemic. His quest for Olympic gold came to an end at the European Continental Championships, where he was denied the final Olympic spot.

Notable Ascents

Burden of Dreams

In Spring 2023, Will visited Nalle Hukkataival’s Burden of Dreams in Finland. This nerve-racking 9A/V17 boulder upped Bosi’s game, taking him more than 20 days to realize the second ascent seven years after Hukkataival’s FA.

“This definitely has been the biggest challenge I’ve ever taken on in bouldering,” he told Climbing Magazine shortly after the ascent, adding that it took “over double the days Alphane took.”

Hard bouldering problems
Will Bosi on Burden of Dreams ©Diego Borello

Will trained for 10 sessions on Aidan Roberts’ 3D-printed replica in order to lock the 8-move climb. He needed 14 more sessions to send it, making it his longest time spent on a boulder problem.

His first attempts on the boulder were live-streamed in March, and he nearly nailed the crux move on the first try. Will described the experience by saying that there are many factors involved in solving this problem, with his skin being the most problematic.

While projecting with a live audience, Bosi said that he enjoyed the experience, and he most definitely felt the hype of the people watching from all over the world.

Bosi solved Burden of Dreams on a warm spring day on April 12th after attempting several variants to get past the sharp, crystal-studded crimps, including taping his fingers. His ascent of BofD has put him on the list of one of the best boulderers in the world.

In the same interview for Climbing, he was asked how it felt compared to his most recent climb of Alphane, and he said, “I’d say it’s above Alphane in terms of difficulty, so if it’s solid 9A then Alphane would be soft 9A.”

With Budren of Dreams and Alphane under his belt, Will Bosi is the second person to have sent two V17 boulders up until now, and as he told, “ I think I’ve learned that I am capable of more than I thought I was and I’m looking forward to finding my own BoDs in the future.” So we’d better watch out for his next big achievement real soon. 

King Capella

On March 9, 2021, at just 22 years old, Will rose to the top of the world’s best climbers, finishing King Capella. Will proposed a grade of 9b+, which meant he was joining Adam Ondra and another five select few who have had the opportunity to redpoint this grade.

Will Bosi climbing King Capella
Bosi making the FA of King Capella 9b ©BandofBirds

Bosi returned to Suriana, where he completed La Capella earlier that year, during a trip to Spain that began in December 2020 as part of his preparations for the next Olympic cycle. Aside from King Capella, he also accomplished two first ascents on La Furia de Jabali (9b) and Last Night (9a).

King Capella, which he FAd after 10 sessions, was unquestionably his greatest achievement for this trip. He describes the route as a powerful and fingery climb with a series of boulder problems stacked on top of each other.

In an interview with Climbing Magazine, Bossi expressed his awe at his realization, “With powerful moves that don’t let up and having big all points off moves, King Capella was like I got to be Chris Sharma for a day, it was amazing!”

Alex Megos and Jakob Schubert made the second and third ascent of King Capella, proposing a grade of 9b.


Video Library


Born and raised in Jiu Valley, Romania, I am a true mountain enthusiast, absorbing knowledge from each sport the area offers. Snowboarder in the winter and a hiker and climber in the summer, I love spending my days up in the Carpathians. I have had a passion for writing ever since I laid my hands on my first keyboard, and I always have a curiosity for gear and great stories. I split my time between various jobs and hobbies, including being a full-time psychologist, repairing skis in the winter, and working with kids at my local gym whenever I have time.

Miho Nonaka
Dean Potter

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