No, your Galaxy S21 Ultra case won't fit the OnePlus 13
The Galaxy S21 Ultra (165.1×75.6mm) and OnePlus 13 (162.9×76.5mm) differ too much for cases to be compatible.
Does a Galaxy S21 Ultra Case Fit OnePlus 13?
Last verified: March 2026
No, a Galaxy S21 Ultra case will not fit the OnePlus 13. The phones have different dimensions that make cases incompatible.
Your Galaxy S21 Ultra case will NOT fit the OnePlus 13. Here's why:
- •Camera module layout is different — cutout won't align
| Spec | Galaxy S21 Ultra | OnePlus 13 | Diff |
|---|---|---|---|
| Height | 165.1mm | 162.9mm | Galaxy S21 Ultra +2.2mm |
| Width | 75.6mm | 76.5mm | OnePlus 13 +0.9mm |
| Thickness | 8.9mm | 8.5mm | Galaxy S21 Ultra +0.4mm |
| Camera Layout | vertical-quad | circular-triple | Different |
| Port | usb-c | usb-c | Same |
Button & Port Alignment
- •New phone has alert slider — old case has no cutout for it
Since your Galaxy S21 Ultra case won't work with the OnePlus 13, here are the highest-rated cases that will:
Ringke
Ringke Fusion-X MagSafe for OnePlus 13
$23.99
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Size Comparison
Wireless Charging & MagSafe
Wireless chargers work with both phones, but magnetic snap varies.
- Both devices support wireless charging. Standard Qi/Qi2 chargers work with either phone.
Galaxy S21 Ultra
Qi only
15W max
OnePlus 13
Qi only
15W max
MagSafe cases are NOT cross-compatible between these devices — the case body is shaped to each phone, even though the internal magnet ring may be the same.
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Frequently Asked Questions
Are Galaxy S21 Ultra and OnePlus 13 the same size?
Galaxy S21 Ultra measures 165.1×75.6×8.9mm while OnePlus 13 measures 162.9×76.5×8.5mm. They are different sizes.
Can I use a Galaxy S21 Ultra screen protector on OnePlus 13?
Edge types differ (curved vs flat) — screen protector won't adhere properly.
What's different between Galaxy S21 Ultra and OnePlus 13 dimensions?
The height differs by 2.2mm, the width by 0.9mm, and thickness by 0.4mm. The camera module layout is also different.
Do I need a new case for OnePlus 13?
Yes, you'll need a new case. The OnePlus 13 has different dimensions than the Galaxy S21 Ultra, so cases are not interchangeable.
Will Galaxy S21 Ultra accessories work with OnePlus 13?
Chargers and cables are compatible since both phones use the same usb-c port. Both support wireless charging, so wireless chargers work with either phone. Cases and screen protectors depend on exact dimensions — check our compatibility results above.
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