How to reduce input lag in CS:GO

Lower your resolution and in-game settings. It may not look as pretty, but your inputs will thank you by being snappier.

I had the same issue, and what worked for me was disabling 'Fullscreen Optimizations' on the CS:GO exe file. Right-click on CS:GO in your Steam library, go to properties, browse local files, find the CS:GO executable, right-click, go to compatibility, and check the box for disable fullscreen optimizations. Also, make sure you're playing in true fullscreen mode for the best performance. Lastly, a high refresh rate monitor and a good gaming mouse can drastically reduce perceived input lag.

Okay, first thing's first, make sure V-Sync is off in your graphics settings. It's notorious for causing input lag. Also, check out your launch options in Steam for CS:GO; adding '-high' can prioritize CS:GO in your CPU, improving responsiveness. Another tip is to set your Nvidia or AMD graphics settings for maximum performance. And don't forget to keep your drivers up to date, seriously, it can make a difference.