CSGO’s demo viewer’s new update is fantastic addition

By Nick Johnson


Oct 19, 2020

Reading time: 3 min

With all of Counter-Strike: Globals Offensive’s small changes over the past several weeks, the update to the game’s demo viewer went unnoticed by the game’s player base. But after testing using all different types of demo files, the verdict is in.

CSOG’s new and improved demo viewer is one of the best quality of life changes Valve has made to the game in years.

Before breaking down the technical details around how it works, let’s just say that players won’t even have time to grab a drink when fast-forwarding or rewinding demos before CSGO has the demo ready to play. Before the update, they could have cooked an entire mean. 

The game’s demo files have a massive amount of information inside of them. They have data on player positions, velocity, momentum, and direction. Server demos, like the ones available from websites, contain every single “event” that happens in a CSGO match starting from the very first server tick.

At any point in a demo, someone with the right amount of technical knowledge can pull this information out and put it into a table or use it to improve tactics. The demo files themselves are incredible in just how much information they hold. But prior to CSGO’s demo update, every player hated watching demos. That doesn’t seem to make much sense, especially for players who are dedicated enough to want to innovate in Counter-Strike. The problem was that CSGO’s demo viewer had a lot to do at once, and the way it originally did its job was very, very slow.

CSGO’s new demo viewer functions make demo reviews almost painless

A demo isn’t a YouTube video. If some wanted to fast-forward on YouTube, all they have to do is click on the timeline and they’re immediately moved there. But CSGO demos don’t function that way, and they still don’t after the update.

Every time a player watches a demo and wants to move forward or backward inside the demo, CSGO’s engine couldn’t just skip to the round or kill that they wanted to see. Instead, Counter-Strike’s programming made it so the engine had to play back the entire demo, including all of that other information on bullet positions and the angles player were holding prior to that point.

To use YouTube as an example, that would mean that the user couldn’t just skip to a timestamp, but instead had to start the entire video over again and wait for it to “fast-forward” to where the user wanted to go.

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That’s all changed now.

Let’s be clear, CSGO’s demo viewer still isn’t YouTube. Players are much better off going with one of the many third-party viewers that can help log and save information that the player wants from the demo in the first place. But now, most likely connected to CSGO’s recent coaching exploits, CSGO’s developers have “indexed” each demo, meaning that instead of having to reload a demo from the beginning, CSGO’s Source engine can follow breadcrumbs to the closest indexed point before reading the demo from there. It sounds complicated, but the update added what are essentially bookmarks to its demo files. 

In WIN.gg’s testing, that means that demos consistently loaded faster when moving in either direction as it looked for the closest bookmark to get to instead of having only the beginning and end to choose from. The demo index update made watching player demos much faster, but the client did suffer several crashes during the testing. That may or may not be related to the indexing function.

Counter-Stike’s replays were always an inch away from crashing the game. But even if the crashes were related to the indexing, getting back to where a player was before the crash now takes seconds instead of minutes.

Overall, it’s a welcome update. Even with the unfortunate exploit as the driving force behind the update, the game is better for it.