Make sure you choose the right augment at the right time.
Death Ray is a powerful poke and a strong area of denial tool. Use it in combination with Gravity Field to control your enemy's position.
Focus on preventing Cho'Gath from reaching his max size.
Purchasing a few HP items decreases the chances of Cho'Gath killing you quickly.
Rupture has a smoke cloud indicating the area it will strike. Try to watch out for it to prevent Cho'Gath from being able to combo his abilities.
The stat comparisons shown on this page show several influential Viktor vs. Cho'Gath matchup stats that may help you appreciate the distinctions between the pair. Viktor’s KDA ratio ([kills + assists] / deaths) of NaN is more than Cho'Gath’s ratio of NaN, showing that Viktor may be more central to his team's team fighting potential than Cho'Gath..
Viktor often has a similar longest kill spree as his enemy does. Commonly, he takes less damage than Cho'Gath. This is usually reflective of differing health capacities, yet it can also illustrate that the one champion has less mobility and thus is not able to escape further damage when poked or engaged.
Both LoL champions are great champions. Both champs have their strengths, weaknesses, and counters. In League's current meta, Viktor usually fairs equally well when playing against Cho'Gath, with a 50.3% win rate. Thus, Viktor makes an ok counter to Cho'Gath.
While Viktor does have a higher win rate than Cho'Gath, when they face off with one another, Viktor also has a much greater difficulty level that makes him a more challenging character to pick up and master. You should be careful when picking Viktor into Cho'Gathas his relative depth means that you may not be able to unleash his full potential without a significant amount of practice beforehand.
Furthermore, Viktor also has almost no amount of CC and other utility, a similar amount to Cho'Gath. This makes her just as valuable during teamfights, especially when trying to counter champions with a ton of burst damage.
While there isn't a single best champion overall in League of Legends, in Viktor vs Cho'Gath matchups, Viktor is the better champion with a similar win rate, more champion depth, and a similar amount of utility to help out your teammates during late stage team fights.
Viktor is a decent counter for Cho'Gath. You will do well by focussing your gameplay on increasing your gold and cs and taking out objectives. If you can do that, you should be able to stand on your own as Viktor against Cho'Gath.
If you would like to learn all of the intricacies of Viktor to counter Cho'Gath during both the lane and mid / late game phases of League of Legends, you should continue reading to pick up a few extra tricks and insights into this matchup. If you pay attention to the build and suggestions shown above, you should increase your win rate by a lot and be closer to League of Legends pro players.
Viktor most often picks up a similar amount of CS as Cho'Gath. Champs who typically don't earn many minion kills usualy don't have to have much CS to be valuable teammates, such as supports. They are able to scale well off of their abilities and first items alone. Yet, champions with a lot of CS, such as hyper-carries, often require several high cost items to be effective. In either situation, try to surpass the values displayed on this page to do well.
The most important items to focus on in your Viktor versus Cho'Gath build include Rabadon's Deathcap, Shadowflame, and Luden's Companion. When Viktor used at least these three items in his build, he did a lot better vs. Cho'Gath than with most other typical item sets. In fact, Viktor had an average win rate of 50.3% when countering Cho'Gath with this counter build.
To have the best likelihood of defeating Cho'Gath as Viktor, you should use the First Strike, Magical Footwear, Biscuit Delivery, Cosmic Insight, Manaflow Band, and Transcendence runes from the Inspiration and Sorcery rune sets. Of all the rune builds players used for Viktor vs Cho'Gath LoL games, this composite of runes resulted in the best win rate. Notably, these runes provided a 50.3% win rate overall.
By default, tips, stats, and builds on how to beat Cho'Gath as Viktor are displayed for all skill levels, merged. To narrow the statistics and builds to a particular skill level, you can use the selection menu above.