Why exclusive fullscreen breaks the overlay
Exclusive fullscreen hands the entire screen to one game and skips the Windows desktop compositor. That compositor is what every Windows overlay rides on: Discord call popups, Steam overlay, Xbox Game Bar, and Kaption all draw through it. With no compositor in the loop, the overlay either flickers as Windows context-switches between the game and the desktop, or disappears entirely until you alt-tab.
This is a Windows behaviour, not a bug in Kaption. There is no way for a normal desktop app to draw stable pixels over an exclusive-fullscreen swap chain without injecting code into the game process, and we deliberately do not do that, because the whole point of Kaption is staying outside the game.
- Borderless and Windowed mode keep the desktop compositor active.
- Exclusive fullscreen disables it and breaks every overlay, not only Kaption.
- Modern hardware shows no measurable performance loss in borderless mode.
How to switch in Genshin Impact
In Genshin Impact, open Settings → Graphics → Display Mode and pick "Borderless Window" or "Windowed". Apply the change and the game keeps running. You can also press Alt+Enter from the game window in most cases. It toggles between fullscreen and the last windowed mode.
How to switch in Honkai: Star Rail
Star Rail uses the same convention. Open Settings → Graphics → Display Mode and choose Borderless Window. Alt+Enter also works at any time. If the option is greyed out, leave to the title screen first and try again. Some patches lock the mode mid-mission.
After you switch, check the dialogue area
Borderless mode can shift the dialogue box by a few pixels compared to exclusive fullscreen. If your dialogue area was set before you switched, click Detect automatically on the Game and subtitles page, or Adjust the frame to draw it yourself. Kaption saves it for each game, so you do this once.
Why we do not "fix this in the app"
A small number of overlays, such as Discord, Steam and MSI Afterburner, do work in exclusive fullscreen. They achieve that by injecting a DLL into the game process and hooking its DirectX swap chain. That approach is exactly what HoYoverse anti-cheat systems are built to flag, and Kaption has a strict no-injection policy: no DLL hooks, no game memory reads, no process attach. Borderless mode is the safe path that keeps Kaption outside the game.
Step by step
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Open in-game graphics settings
Pause the game and open the Graphics or Video Settings page.
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Change Display Mode to Borderless or Windowed
Either option works. Borderless looks identical to fullscreen on most setups.
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Apply, then verify with Alt+Enter
Alt+Enter should toggle into fullscreen and back. If it forces exclusive mode, leave the toggle off.
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Restart Kaption translation
On Home, click Stop, then Start translating (or press Ctrl+Shift+S twice in the game). Subtitles should now sit cleanly above the dialogue with no flicker.
Questions
How do I make Genshin Impact borderless?
Open Settings → Graphics → Display Mode and choose Borderless Window, or press Alt+Enter in the game window to leave fullscreen. Star Rail works the same way.
Will I lose performance in borderless mode?
On Windows 10/11 with a modern GPU the difference is not measurable in normal play. DX12 titles run a "borderless optimization" path that closes most of the gap, and DX11 titles like Genshin Impact and Honkai: Star Rail are already GPU-bound enough that the compositor cost is in the noise.
Why does Discord overlay work in fullscreen but Kaption does not?
Discord and Steam ship a DirectX hook injected into the game process. That is a deliberate engineering choice with real risk: anti-cheat systems flag DLL injection, and Kaption is built on a no-injection policy. We trade exclusive-fullscreen support for a tool that stays outside the game.
Does Alt+Enter always work?
Most of the time yes, but a few patches restrict it to the title screen. If pressing Alt+Enter does nothing, change Display Mode in the in-game settings instead.
I switched to borderless and the subtitle is in the wrong place.
Set the dialogue area again: click Detect automatically on the Game and subtitles page. Borderless mode can shift the dialogue box a few pixels, and the area is saved per game, so you only do this once after the switch.
