The Liquid Contact Indicator (LCI) in an iPhone is a small, built-in sensor designed to show if the device has been exposed to water or any liquid containing water. Typically, the LCI is a tiny adhesive dot placed in various places inside the iPhone, such as the SIM card slot and other ingress points where moisture is likely to enter. The LCI is normally white or silver in color and changes to bright red if it comes into contact with water or liquid. This change is irreversible and used by Apple and repair technicians to assess water damage in the device.
To check if the LCI has changed color, the most common method is to locate it in the SIM card slot of the iPhone. This involves removing the SIM card tray using the SIM eject tool or a paperclip. When the tray is removed, shining a light or using a magnifying glass to look inside the SIM card slot should reveal the LCI. If the small dot visible there is white or silver, the phone has not been exposed to liquid. If the dot is red, this signals that the phone has likely been in contact with liquid, which may void the Apple warranty for water damage.
Note that starting from the iPhone 14 series, especially in U.S. models with eSIM and no physical SIM tray, there may not be an externally visible LCI. In such cases, Apple may rely on internal indicators not accessible to the user. On older models, the LCI is clearly visible in the SIM card slot. The LCI is sensitive to liquids like water, coffee, sodas, and other drinks, but will not be triggered by humidity or temperature changes within typical environmental ranges. Solvents like isopropyl alcohol do not activate the LCI. The color change happens because water dissolves the white coating revealing the red color beneath.
If your LCI is red, it means the phone has encountered liquid and this could cause damage such as corrosion, display issues, fogged cameras, or malfunctioning buttons and sensors like Face ID or Touch ID. Even a small drop of rain can trigger the LCI without necessarily causing immediate damage, but it indicates moisture exposure.
When checking the LCI, it is helpful to use a bright light source at an angle and a magnifying glass to clearly see the indicator. The color should be compared carefully as sometimes the red can appear faded or ambiguous, but generally, it is a clear bright red if water contact has occurred.
In summary, to check if an iPhone's Liquid Contact Indicator has changed color:
- Remove the phone case if applicable.
- Locate the SIM card tray on the side of the iPhone.
- Use the SIM eject tool or a paperclip to remove the SIM tray.
- Shine a flashlight into the empty SIM slot.
- Look for a small dot inside; it should normally be white or silver.
- If the dot is red, the LCI has been triggered, indicating water or liquid contact.
- On newer iPhones with no SIM tray, the LCI may be internal and not visible externally.
This method is the primary user-level way to check for signs of water exposure on iPhones and is widely used by Apple support and technicians to make warranty and repair decisions. The LCI's color change is a crucial indicator for liquid damage assessment.
Detailed information about the LCI, its location, appearance, conditions activating it, and how to check it is documented by Apple and various technology sources, confirming these points.