Collapse Launcher detects when a new game version or pre-download is available and gives you full control over when and how you download it. Two download technologies reduce the amount of data you need to transfer: Sophon (chunked differential downloads) and HDiffPatch (binary delta patches for Honkai Impact 3rd).Documentation Index
Fetch the complete documentation index at: https://mintlify.com/CollapseLauncher/Collapse/llms.txt
Use this file to discover all available pages before exploring further.
Preload (pre-download)
When miHoYo/HoYoverse makes a new version available for pre-download before its official release date, Collapse shows a notification bar on the home page.Starting a preload
Check for the preload notification
When a preload is available, a notification bar appears at the bottom of the home page showing the upcoming version number and a Pre-download button. The bar also indicates whether Sophon mode is active.
Click Pre-download
Click the Pre-download button to begin downloading the pre-release package. The button changes to a Pause control and the notification bar displays:
- Total download progress (size transferred / total)
- Per-file progress
- Download speed
- Estimated time remaining
Pause and resume
You can pause the download at any time using the Pause button. To resume, click Resume. The download continues from where it left off.
Delta patch detection (Honkai Impact 3rd)
For Honkai Impact 3rd, Collapse checks whether a delta patch (HDiffPatch) is available before showing the standard preload bar. If a delta patch is detected, the notification bar displays a message indicating that a smaller incremental patch will be applied at update time rather than a full package download. In this case, the Pre-download button is hidden because no separate pre-download step is required.Updates
When a new version is released and your installation is out of date, the Start button is replaced by an Update button.Sophon differential downloads
For games that support Sophon, Collapse downloads only the chunks of each file that have changed between your installed version and the new version. This significantly reduces download size compared to downloading full replacement packages. During a Sophon update, the progress display shows two layers:| Indicator | Meaning |
|---|---|
| Total progress | Overall percentage, speed, and estimated time across all files |
| Per-file progress | Speed and size for the individual file currently being processed |
HDiffPatch delta patches (Honkai Impact 3rd)
Honkai Impact 3rd updates can use HDiffPatch, a binary delta-patch format. Instead of downloading a full replacement file, Collapse downloads a small.hdiff patch and applies it to the existing file on disk. This results in much smaller update downloads — often under 1 GB even for significant version bumps.
When an HDiffPatch update is in progress, the standard progress display is used (not the Sophon grid). Any leftover .hdiff files are cleaned up by the repair tool if they are found after an update.
Standard package downloads
When Sophon is not available, Collapse falls back to downloading full replacement packages. The progress display shows total size and speed with a single progress ring.Update process
Package verification
Collapse verifies that downloaded packages are intact before applying them. If verification fails, it re-downloads the affected packages automatically.
Installation
Once all packages are verified, Collapse applies them to the game directory. For HDiffPatch, this involves patching existing files in place. For Sophon, changed chunks are written directly.
Post-update actions
Just like post-install, you can configure an automatic action to run after an update completes: launch the game, hibernate, restart, or shut down the PC. Configure this in Collapse settings before starting the update.Speed limiter
Collapse includes a global download speed limiter that applies to all downloads — installations, updates, preloads, and cache updates. To configure the speed limit:- Click the Download Settings button that appears on the home page during any active download.
- Set the maximum download speed. Setting the value to 0 disables the limit.
Update notifications
Collapse uses the Windows system tray to notify you of completed downloads when the launcher window is not in focus:| Event | Notification |
|---|---|
| Preload complete | Shown when preload finishes while window is unfocused |
| Game install complete | Shown when installation finishes while window is unfocused |
| Game update complete | Shown with the new version number while window is unfocused |
| Cache check complete | Shown with the count of files needing update |