Emoji renders as [?] boxes on iOS 26 simulator (Xcode 26)

[Mile-Away]

Description

Emoji characters render as [?] placeholder boxes in React Native <Text> components on the iOS 26 simulator (Xcode 26.3, build 17C529). This affects all emoji — inline, standalone, flag sequences, and Unicode escape sequences.

Safari running in the same simulator renders emoji correctly, confirming the font (AppleColorEmoji) is present and registered. The issue is specific to React Native's CoreText text rendering path.

Steps to reproduce

1. Create a new React Native project (tested with RN 0.84.1 via @react-native-community/cli)
2. Add emoji to a <Text> component:

   <Text>Hello 🚀 World 🎨 Test ✅</Text>
   <Text>Pure emoji: 😀😃😄😁😆😅🤣😂</Text>
   <Text>Flags: 🇺🇸 🇨🇳 🇯🇵 🇬🇧</Text>

3. Run on iOS 26 simulator (any device — iPhone 16, iPhone 17 Pro, etc.)
4. All emoji appear as [?] boxes

Expected behavior

Emoji should render using the AppleColorEmoji font, as they do in Safari and native UIKit apps on the same simulator.

Actual behavior

All emoji render as [?] replacement characters/boxes.

Environment

• React Native: 0.84.1 (also reproduced on 0.83.2)
• JS Engine: Hermes (also tested with JSC — same result)
• Architecture: New Architecture / Fabric (also tested with Old Architecture — same result)
• Xcode: 26.3 (build 17C529)
• iOS Simulator: 26.3.1 (23D8133)
• macOS: Darwin 25.3.0 (arm64)

Investigation done

• ✅ Confirmed AppleColorEmoji-160px.ttc exists in the simulator runtime at CoreAddition/AppleColorEmoji-160px.ttc
• ✅ Confirmed font is registered (CTFontManagerRegisterFontsForURL returns "already exists")
• ✅ Confirmed Safari in the same simulator renders emoji correctly
• ✅ Tested Hermes vs JSC — no difference
• ✅ Tested New Architecture vs Old Architecture — no difference
• ✅ Tested RN 0.83.2 and 0.84.1 — both affected
• ✅ Attempted RCTSetDefaultFontHandler with AppleColorEmoji in cascade list — no effect
• ❌ Unable to test on iOS 18 simulator (Xcode 26 only ships iOS 26 runtime)

Notes

• This may be an iOS 26 simulator-specific issue (real devices may be unaffected)
• The root cause appears to be in how React Native's native text rendering (via CoreText/TextKit) resolves the emoji font cascade on iOS 26
• No older iOS simulator runtimes are available through Xcode 26 to compare

[react-native-bot]

Warning

Missing reproducer: We could not detect a reproducible example in your issue report. Reproducers are mandatory and we can accept only one of those as a valid reproducer:

• For majority of bugs: send us a Pull Request with the RNTesterPlayground.js edited to reproduce your bug.
• If your bug is UI related: a Snack
• If your bug is build/upgrade related: a project using our Reproducer Template

You can read more about about it on our website: How to report a bug.

[Mile-Away]

Reproducer

https://github.com/Mile-Away/rn-ios26-emoji-reproducer

Created from the official reproducer template. The App.tsx contains various emoji rendering tests (inline, pure sequences, flags, skin tone modifiers, heart variants).

To reproduce:

cd ReproducerApp
yarn install
cd ios && bundle install && bundle exec pod install && cd ..
yarn ios

Run on any iOS 26 simulator device. All emoji will render as [?] boxes instead of colorful emoji glyphs.

[Mile-Away]

Update: Confirmed simulator-only issue

Tested on a physical iPhone 17 Pro Max (iOS 26) — all emoji render correctly. This confirms the bug is iOS 26 Simulator only, not affecting real devices.

The issue appears to be in how the iOS 26 Simulator's CoreText font cascade handles AppleColorEmoji when used through React Native's native text rendering path (UIKit/CoreText). Safari in the same simulator renders emoji fine, suggesting WebKit has its own font fallback that bypasses this issue.

TL;DR: Simulator bug only. Real devices are unaffected.

[CllDMR]

Having same issue. Images from Safari with example website.