GTA 3 Browser Save Data, OPFS Cache and Local Storage Explained

The phrase “saved in the browser” can refer to several different things. In GTA III Browser, the largest persistent item is the compressed game archive stored in OPFS. Game preferences are much smaller. Save-game persistence is a separate subsystem and should not be confused with the archive cache.

The OPFS archive cache is not your game progress

OPFS stores the compressed GTA III archive so the site can reuse it later. Deleting that cache means the game data may need to be downloaded again, but it is conceptually different from a mission save or player progress file.

Think of OPFS here as the browser equivalent of keeping an installation package locally. It helps the runtime reconstruct its game filesystem when you start a fresh session.

What the browser remembers on the homepage

Small preferences such as the FPS limit and touch-control mode can be stored using browser local storage. These values are tiny compared with the game archive and can be reapplied when you return.

If you clear all site data, both these preferences and the OPFS archive may disappear because browsers group multiple storage technologies under the same site origin.

Current save persistence expectations

The re3 WebAssembly codebase includes browser save-system work, but persistence behavior can depend on the current build and runtime path. The project should not promise that every save created in every browser/device configuration is permanently backed up simply because the archive cache is persistent.

For important progress, treat browser-local storage as device/browser-specific unless you have explicitly verified a backup/export workflow in the current build.

The large archive cache lives in browser storage so later visits can avoid another full download.

Why browser profiles matter

OPFS and local storage are scoped to the browser origin and profile. Chrome Profile A and Chrome Profile B do not automatically share GTA III Browser storage. A normal browser window and a private/incognito window can also have different persistence behavior.

Likewise, opening a different domain or development URL creates a different origin, even if the site code looks identical.

What happens when you clear site data

Browser settings such as “clear cookies and site data” can remove origin storage. For this project, that can include the large cached archive, preferences and any other persistent files the browser associates with the site.

If your goal is only to troubleshoot graphics or a stale deployment, try a hard refresh first. Reserve site-data deletion for cases where storage itself is suspected.

Storage persistence and free disk space

The launcher can request persistent storage, but the browser remains in control of quotas and device storage. Running very low on disk space is risky for any large browser-based game cache.

Keep enough free space for the archive plus browser overhead. The active session may also use significant RAM during extraction, so disk capacity and memory capacity solve different problems.

A practical backup mindset

Separate three questions: “Is the game archive cached?”, “Are my settings remembered?” and “Is my game progress backed up?” A yes to one does not imply a yes to the other two.

As the browser save manager evolves, a reliable export/import path is the safest long-term model because it gives the player a file outside browser-managed storage.