You can download HTML5 games for offline play in some cases, not all.

Single-player titles built from static HTML, JavaScript, and asset files can be saved with Save Page As → Webpage, Complete, mirrored with wget --mirror, or pulled with HTTrack, then run locally through a small web server.

Multiplayer titles (Krunker, Bullet Force, .io games) and games that fetch level data, ads, or scores from a server cannot run offline by any method.

The cleanest offline path is the one developers build in — a Progressive Web App (PWA) that installs from the browser's address bar. You can download many HTML5 games for offline play, but not all.

Single-player titles that load only static HTML, JavaScript, and asset files can run from a local folder.

Multiplayer games — including Krunker, Bullet Force, and most .io titles — and games that fetch level data, scoreboards, or ad slots from a server cannot run offline, regardless of how cleanly you mirror their files. The distinction is what the game does after page load.

A small platformer that loads index.html, a JavaScript bundle, sprite sheets, and audio files makes no further network calls once running — it is a perfect offline candidate.

A browser FPS like Krunker or a shooter like Bullet Force opens a WebSocket to a game server, fetches matchmaking, and validates the client; nothing about saving the HTML changes that.

The same applies to most titles in the .io games category, which are multiplayer-first by design. "Download" in this context means mirroring a web build to disk so it can launch from a local file path or a local server, not extracting a single executable.

Verdict: "Single-player static HTML5 games download cleanly. Anything with a live server connection — multiplayer, leaderboards, ads, level streaming — does not." For a single-page HTML5 game, use your browser's Save Page As → Webpage, Complete.