The Cause of Duplicate Text Messages on Android
Several problems can cause an Android device to send duplicate text messages but typically the issue tends to fall into several broad categories.
An issue with your Wi-Fi or mobile data networkAn incorrect setting in the messaging appA problem with the messaging appA problem with your Android device
In most cases, duplicate text messages are caused by the first two of these four problems. If that’s the case, it can be resolved quickly. Problems with an app or device, however, are more difficult to fix.
How to Fix Duplicate Text Messages on Android
Follow the steps below to stop sending duplicate text messages on Android. Be sure to follow the list in order, as the most likely solutions are placed first. The setting is located under Settings > Chat Features in the Messages app. Third-party messaging apps usually have a similar feature, though the feature may be labeled differently. This feature resends a message as an SMS/MMS message if it believes the message failed to send over Wi-Fi or mobile data. An Android device may incorrectly do so even when a message was successfully sent, causing a duplicate message. The setting is located under Settings > Chat Features in the Messages app. Third-party messaging apps usually have a similar feature, though it may be labeled differently. Chat Features uses Wi-Fi or mobile data to send a message instead of SMS services. This is usually preferred but could cause duplicates if your Android device mistakenly tries to do both at once. The setting is located in the Settings app under Apps > Messages > Storage & cache. The cache is used to store a variety of configuration data for an app. Clearing it will fix temporary problems causing duplicate messages.