Travel v5.9.6
Does China Railway 12306 work on iPhone Duo?
It works, but with black bars. China Railway 12306 5.9.6 is built with the iOS 26.5 SDK, so iPhone Duo runs it in a phone-sized window on the inner display.
At a glance
- Inner display (7.6″)
- Black bars
- Outer display (5.4″)
- Works normally
- Built with
- iOS 26.5 SDK
- Version 5.9.6, read Oct 25, 2026
- iPad version
- Yes
- Layout already handles big screens
- Latest version
- v5.9.6
- Jun 26, 2026
- Duo in release notes
- Not yet
About China Railway 12306
China Railway 12306 is made by 中国铁道科学研究院集团有限公司 and first came out on the App Store in September 2013. It has 1,043 ratings on the US App Store, averaging 2 stars. Version 5.9.6 came out on Jun 26, 2026 and needs iOS 11.0 or later. It's free to download.
From its App Store listing:
中国铁路出品，人民铁路为人民，买火车票就用铁路12306！铁路12306网站（含手机客户端）是中国铁路唯一官方火车票网络售票平台，从未授权任何第三方平台发售火车票。 我们的特色： 【售票无加价】不收取加速包费用，不捆绑保险销售，不收取会员费，让您购票放心。 【信息更准确】晚点、停运信息，列车出发、到达信息，车厢、车型信息，第一时间获知，让您出行安心。 【功能更全面】火车票、机票、汽车票、网络订餐、酒店住宿、旅游等近百项功能，让您旅行无忧。 【服务更温馨】满足老年人的大字版，满足视障等特殊人群的无障碍版，让您使用便捷。 主要产品及服务： 【火车票预订】 1. 无票候补。车票售完不用慌，无票候补帮您忙。提交候补需求，当因退票、改签或新增列车等产生可供发售的车票时，自动为您出票。 2. 选座选铺。喜欢靠窗看风景？喜欢靠过道便捷？喜欢上铺清净？喜欢下铺方便？选座选铺一键指定心意座/铺位。 3. 智…
On the inner display
Apps built with older SDKs are placed in a phone-sized safe area on a black background. Everything works; you just don't get the bigger screen.
In Split View
iPhone Duo is the first iPhone that can show two apps side by side, and every app takes part — including China Railway 12306. Open it on the inner display, then add a second app next to it. You can save the pair and come back to it later.
Duo-specific features
None confirmed yet. Duo-specific features include side toolbars, layouts that react to the fold, and content on the outer display while the app is open inside.
Evidence & history
App build,
Version 5.9.6 is built with the iOS 26.5 SDK
Apple runs apps built with the iOS 26 SDK or earlier in a phone-sized window on the inner display.
- : Not confirmed yet → Black bars — built with the iOS 26.5 SDK
Latest release notes
Version 5.9.6 · Jun 26, 2026
【新版本特性】 1.页面焕新升级，优化功能布局； 2.提升产品体验，解决已知BUG。
Questions
Does China Railway 12306 work on iPhone Duo?
It works, but with black bars. China Railway 12306 5.9.6 is built with the iOS 26.5 SDK, so iPhone Duo runs it in a phone-sized window on the inner display.
Does China Railway 12306 work on the outer display?
Yes. iPhone Duo's 5.4-inch outer display behaves like a regular iPhone screen, so every iPhone app works there as usual.
Can I use China Railway 12306 in Split View on iPhone Duo?
Yes. On iPhone Duo every app can be placed side by side with another app on the inner display — developers don't need to opt in. How comfortable it feels at half width depends on the app's layout.
Why does China Railway 12306 have black bars on iPhone Duo?
Apps built with the iOS 26 SDK or earlier run in a phone-sized window on the inner display, and iOS 27 builds can still leave some space empty. The bars disappear once the developer rebuilds the app with the iOS 27.1 SDK — you only need to update the app.
When will China Railway 12306 fill iPhone Duo's inner display?
When its developer releases an update built with the iOS 27.1 SDK or later. We read the SDK of every new version of China Railway 12306 within about a day of its release and update this page.
What can I do about the black bars until then?
Use China Railway 12306 on the outer display, where it works like on any iPhone, or put it in Split View next to another app on the inner display so less of the screen goes unused.