Frequently Asked Questions

Yes — the core viewer is free and will stay free. No subscription, no trial, no credit card required. The site is supported by non-intrusive display ads. Premium features (cloud replay storage, team tools, advanced analytics) are on the roadmap, but the demo viewer, Steam sync, share links, and all current functionality are free forever.

Your .dem file is parsed entirely in your browser using WebAssembly — it never leaves your device. The only exception is if you choose to share a replay link: clicking Share uploads the parsed replay data (not the raw demo) to our servers so others can view it. Shared replays are stored for 7 days then automatically deleted.

Any modern browser with WebAssembly support: Chrome, Firefox, Edge, and Safari (iOS 16.4+). Chrome gives the best performance on desktop. Internet Explorer is not supported.

Yes. The viewer and shared replays both work on iOS and Android. Touch controls are supported for panning and zooming the map. Demo parsing on mobile is slower than desktop due to hardware constraints, but it works. Safari on iOS requires iOS 16.4 or later.

The viewer requires an internet connection to load the page and map images. Once loaded, demo parsing itself runs entirely in-browser and does not need a network connection. If you lose connectivity mid-session, an already-loaded demo will continue to play back normally.

In CS2: Main Menu → Your Matches → find the match → Download. This saves a .dem.bz2 file to your CS2 folder — usually Steam/steamapps/common/Counter-Strike Global Offensive/csgo on Windows, or ~/.steam/steam/steamapps/common/Counter-Strike Global Offensive/csgo on Linux. Both .dem and .dem.bz2 are supported — no need to decompress first. See the full Upload Guide for step-by-step instructions.

A .dem file is the raw CS2 demo. A .dem.bz2 is the same file compressed with bzip2 — this is what CS2 downloads from Valve's servers to save bandwidth (typically 30–60 MB instead of 100–200 MB uncompressed). CS2 Replays decompresses .bz2 files automatically in-browser, so you can drop either format directly.

Yes. Demo files are large (typically 30–120 MB compressed) and parsing them in-browser via WebAssembly takes 10–30 seconds depending on your device and match length. This is a one-time cost per demo — once parsed, scrubbing between rounds and playback are instant.

Yes — any standard CS2 .dem file works regardless of platform. Matchmaking, FACEIT, ESEA, and LAN demos are all supported. GOTV/observer demos are also supported.

A few things to try:

1. Make sure the file is a CS2 demo (.dem or .dem.bz2). CS:GO demos from before the CS2 update use a different format and are not supported.

2. Check the file isn't corrupted — re-download from CS2 or the platform it came from.

3. On mobile, very large demos (over 150 MB compressed) can run out of memory. Try a shorter match or use a desktop browser.

4. Make sure your browser is up to date — Chrome and Firefox both receive regular WebAssembly improvements.

Sign in with Steam, then open the Steam auth code page and click Create Authentication Code under Game Authentication Codes. Paste the code into your dashboard and the viewer will fetch your recent competitive matches automatically. See the full Steam Auth Code guide for screenshots and details.

No — the Game Auth Code is not your password and does not give access to your Steam account. It's a temporary token Steam generates specifically for match history API calls. Your login credentials never leave Steam. The code is used to fetch your recent match IDs from Valve's servers so we can download the demos for you. You can revoke it at any time from the same Steam page.

This usually means one of the following:

1. Your auth code has expired — codes are valid for about 24 hours. Go back to the Steam page and generate a fresh one.

2. Your CS2 match history privacy is set to private — set your game details to public in Steam profile privacy settings.

3. You haven't played any ranked competitive matches recently. Casual, deathmatch, and other modes are not included in the match history API.

Positions are parsed at full 64-tick resolution from the demo file and displayed on Valve's official radar images using the exact coordinate transform CS2 uses internally. The overlay is as accurate as the demo data itself — positions are not interpolated or estimated.

Load your demo, then click the Share button in the toolbar. This uploads the parsed replay data to our servers and generates a short link. Anyone with the link can view the replay in their browser — no account required. Shared replays expire after 7 days.

Yes. Any publicly available CS2 .dem file works — pro match demos from HLTV, Blast, or other tournament organisers can all be loaded. Just download the demo and drop it onto the viewer.