A demo is the game's own recording of a match: every player's position, every grenade and every round's money, tick by tick. Prefire reads one and turns the few things worth knowing about a player into pictures you can take in during the warmup.
From match room to study
- You find a match on FACEIT. With the browser extension set up and the Windows app signed in, the app hears about your match room and looks the match up through Prefire's server. While the map is being voted it tells you Match found.
- The map gets picked. The app says Match found on Inferno (or whichever map it is) and puts both rosters on screen, your opponents first.
- You pick who to study. Usually their AWPer, or whoever anchors the site you like taking.
- Prefire finds that player's last match on this map, fetches its demo from FACEIT and reads it on your PC. This step needs an active trial or plan.
- The picture arrives. Positions and Kill spots are on screen as soon as the demo is open. Top HEs, Top flashes and Force buys need a second pass over the demo, which runs in the background while you look at the first two, and usually takes a few seconds.
- You play. Minimise Prefire to the tray, where it draws nothing, and alt-tab back to it in a tactical timeout if you want another look.
You can skip the first three steps: drop any .dem file on the window and pick the player yourself.
The same, in your browser
Click Watch demo in a match room, signed in at prefireapp.com/web. The extension sends the demo's link to Prefire's server instead of downloading the file. The server fetches the demo, reads it once (one demo at a time, so yours may wait in a short queue) and keeps the results, and the study opens in a new tab. Anyone who opens that demo later gets it at once. The server deletes the demo as soon as it has read it.
Where the numbers come from
Every number in a view is read from the demo, with the same engine in the Windows app and in the web app, so the two always agree.
| View | What it reads from the demo |
|---|---|
| Positions | Where the player stood on every tick of every live round, split by side. Warmup, freeze time and time spent dead are left out. |
| Top HEs | Every HE grenade the player threw, where they threw it from, where it burst, and the damage it did to enemies. |
| Top flashes | Every flashbang the player threw, who it blinded and for how long, and the kills it helped their team make. |
| Kill spots | Where the player stood for each kill, with the weapon, split by side. |
| Force buys | Every round's money at buy time, what the player and their team bought, and a 2D replay of the rounds worth watching. |
The five views explained says how each one is ranked and worked out.
What Prefire never does
It never attaches to Counter-Strike 2, reads its memory, draws over it or runs inside it. It reads finished matches only: demos you could download yourself from the match room.