About CS2 Replays

What It Is

CS2 Replays is a web application for watching Counter-Strike 2 demo files round by round. You can see every player's position on the map in real time, track grenade trajectories, watch kill events unfold, and review match and player statistics — all from your browser.

It supports all active duty maps, works with demos from any platform (Matchmaking, FACEIT, ESEA, LAN), and can share replays as a link that anyone can open — including on mobile.

How It Works

When you drop a .dem or .dem.bz2 file onto the page, it is parsed entirely in your browser using WebAssembly — a near-native execution environment built into every modern browser. The parsing engine (demoparser2) is compiled from Rust to WASM and runs locally on your machine.

Your demo file never leaves your device. Nothing is uploaded to any server unless you explicitly click Share, at which point only the parsed replay data (not the raw .dem file) is uploaded so others can view it.

Once parsed, the viewer renders player positions and game events on Valve's official radar images using the same coordinate transform CS2 uses internally, giving pixel-accurate positioning at full 64-tick resolution.

Tech Stack

No framework, no bundler, no build step. The entire site is static HTML, CSS, and JS files served directly from Cloudflare's edge network.

Privacy First

The core design principle is that your replay data stays yours. Demo files are parsed locally. Steam sign-in stores only your Steam ID and username in your browser's localStorage — nothing is shared with third parties. Analytics are handled by Cloudflare Web Analytics, which is cookie-free and anonymous.

The site carries Google AdSense display ads to keep the viewer free. See the Privacy Policy for full details on data handling.

Why It Exists

CS2's built-in replay system requires launching the game, waiting for the demo to download through Steam, and navigating a clunky in-game UI. CS2 Replays is designed to be instant — drop a file, get a clean overhead view in seconds, share it with a link. Useful for post-match reviews, coach feedback, and quick clip analysis without loading the game.