A flash in climbing means completing a route or boulder problem on your very first attempt, with some prior knowledge of how to climb it. That prior knowledge is what separates a flash from an onsight, where you go in completely blind. You might have watched someone else climb the route, received tips about a tricky sequence, or studied a video beforehand. As long as you never physically attempted the climb before and you send it first try, it counts as a flash.
Flash vs. Onsight vs. Redpoint
These three terms describe a spectrum of how “pure” your send was. An onsight sits at the top: you climb a route on your first attempt with zero information, no watching others, no tips, nothing. A flash is one step down: still first try, but you had some kind of beta (climbing jargon for information about the moves). A redpoint means you eventually completed the route after previous failed attempts or practice runs.
Think of it this way. If a friend tells you “the third hold is a pinch, match hands there before reaching left,” and you then climb the route clean on your first go, that’s a flash. If nobody told you anything and you figured it out yourself on the first go, that’s an onsight. If you fell off twice before finally sending it, that’s a redpoint.
Among climbers, onsights are generally considered the most impressive style of ascent, followed by flashes, then redpoints. That said, a flash at your limit is still a serious achievement, and many climbers specifically chase flash sends as a way to test their ability to quickly read and execute movement on new terrain.
What Counts as “Prior Knowledge”
The line between a flash and an onsight comes down to what you knew before pulling on. Any of the following would make a successful first attempt a flash rather than an onsight:
- Watching someone else climb the route, even if they fell off partway through
- Receiving verbal tips about holds, body positions, or sequences
- Watching a video of the route being climbed
- Reading a guidebook description that details specific moves or crux sections
Simply knowing a route’s grade or general style doesn’t typically disqualify an onsight. The distinction matters most when the information gives you a tactical advantage you wouldn’t have had otherwise, like knowing to use a hidden foothold or skip a tempting but dead-end sequence.
How Flashing Works in Competitions
In official IFSC (International Federation of Sport Climbing) competitions, flash rounds are formally declared. When a round is designated as flash format, competitors are shown a demonstration of the routes or boulders before they start. Coaches and team officials are also allowed to share information about the climbs with competitors before, during, and after their attempts.
This contrasts with onsight rounds, where climbers get a limited observation period to look at the wall but can’t receive outside information or watch other competitors climb. In onsight format for bouldering, climbers can only touch the marked starting holds from the ground.
Under the 2025 IFSC World Cup scoring system for bouldering, a flash is worth the full 25 points for a top. Each additional attempt costs 0.1 points, so sending on your second try earns 24.9 points. That small penalty makes flashing a boulder a meaningful competitive advantage, especially when scores are tight.
Flashing in Bouldering vs. Route Climbing
The concept works the same in both disciplines, but the practical experience feels quite different. Bouldering problems are short, often four to eight moves, so a flash attempt usually comes down to whether you can read the movement correctly and execute it with enough power on your first burn. You might watch a few people try the problem, note which hand goes where, then step on and send it clean.
On a sport climbing route, flashing is harder in a different way. Routes can be 25 to 35 meters long with dozens of moves, and endurance becomes a factor. You might have beta for the crux section but still need to manage your pump (forearm fatigue) well enough to execute when you get there. Flashing a long route requires both good information and the fitness to use it under pressure.
The Etiquette Around Flash Attempts
One of the biggest unwritten rules in climbing is not to “spray beta,” which means giving unsolicited advice about how to climb something. This is especially relevant when someone is trying to flash or onsight a route. If you shout “use your left foot on that orange hold!” to a climber who didn’t ask, you’ve potentially ruined their onsight attempt and forced their send into flash territory, or worse, taken away the fun of figuring it out themselves.
The polite move is to ask if someone wants beta before offering it. Some climbers actively seek it out because they want the flash. Others prefer to work things out independently. At the crag or in the gym, a quick “do you want any tips?” respects both approaches. If someone is visibly projecting a route and grinding through attempts, they’re past the flash stage anyway, and sharing information is usually welcome at that point.
Why Climbers Care About Flashing
Tracking whether you flashed, onsighted, or redpointed a route is how climbers measure progress beyond just the grade number. Flashing a route at your limit means your movement reading, power, and tactics are all sharp enough to perform without rehearsal. Many climbers set flash goals that sit one or two grades below their redpoint max as a benchmark for overall ability.
There’s also a psychological element. Flash attempts carry a certain pressure because you know you only get one shot at it. Once you fall, the flash is gone forever on that route. That single-chance dynamic makes flashing feel distinct from projecting, where you can try as many times as you need. For a lot of climbers, the rush of pulling through an unfamiliar sequence without falling is one of the most satisfying experiences the sport offers.