cs2d

Counter-Strike 2 is a competitive multiplayer shooter by Valve, the latest entry in the Counter-Strike series and one of the most played games in the world, with hundreds of thousands of concurrent players at any given moment and a thriving professional scene. After every match the game can record a demo: a full replay of everything that happened, which is exactly what makes deep post-match analysis possible.

I have played Counter-Strike since I was a kid, and analyzing those demos with friends after a PUG was always part of the fun. The problem was the tooling. Every existing analyzer had too much friction: install a database, spin up Docker, wire up config, all before you could watch a single round, and the visual side still felt like an afterthought.

I just wanted a simple way to review the comms and positioning of our matches, so I built the tool I always wished existed: instant to open, good-looking, and fully client-side. You drop a .dem file and rewatch the match round by round. No install, no upload, not a single byte leaving your machine. It is open source so it can grow with the CS2 community, and it is a first step toward building in esports.

2D replay

At its core is a round-by-round 2D replay of player movement, duels and timing, with a live scoreboard, killfeed and in-game chat, and auto-advance between rounds. The original player comms are replayed alongside the action, so you hear the calls exactly as they happened while you watch the round unfold.

Heatmaps and utility analysis

Beyond the replay, the analyzer turns a match into stats. Heatmaps for deaths, presence and utility can be filtered by side, player and round, with multi-floor support for maps like Nuke and Vertigo. There is a full breakdown of grenade trajectories for smokes, molotovs, HEs, flashes and decoys, plus flash effectiveness (who blinded whom and for how long) and HE / molotov damage dealt per player.

Economy

A per-round economy breakdown shows buy types, equipment value and money flow, so you can see where a team’s eco broke down or which force-buy swung the half.

Under the hood

The whole thing runs in the browser. The demo is read and parsed in a Web Worker by a custom Rust parser compiled to WebAssembly, built on top of source2-demo, so nothing is ever sent to a server. Uploads can be .dem, .gz, .zip or .zst (CS2 / Source 2), with decompression handled client-side before parsing.

The app is Vue 3, Vue Router and Vite, styled with Tailwind CSS v4 and Reka UI. An analyzed match can be exported as a compact .cs2dv file and reopened instantly without re-parsing the original demo, and a local history keeps your recently analyzed demos in the browser. The interface is translated into nine languages so far: English, Portuguese, Spanish, French, German, Russian, Polish, Turkish and Ukrainian.

There is also a built-in showcase to rewatch Counter-Strike Major playoff matches in 2D, map by map, with the replays bundled in the project. Fully open-source under MIT license, and contributions are welcome.