Step 1 : Open ES File Explore. Make you sure that root access is ON. (Check comment section for How to enable root access.)
Step 2 : Open the following directory and edit the WhatsApp_Preferences.
Path of Directory :data/data/com.whatsapp/shared_prefs/
Step 3 : Edit the WhatsApp_Preferences.xml file using the Editor.
Once you found the above mentioned location, you have to do find WhatsApp_Prefrences.xml file and modify, Below is the part of the file which you will have to modify so that you can add more than the existing whatsapp group limit. Look for “int name=”participants_size_limit”value=”100″ and replace the 100 by the maximum number of members/participants you would like to have in your Group, Here I’ve replaced by 1000 because I want 1000 members in the WhatsApp Group, You can keep the number depending on your needs. After changing it, save the file and close it.
Step 4 : Restart the device.
Step 5: Open WhatsApp and create new group and add members, you will see that the member limit is 5000 maximum participants.
WhatsApp recently introduced WhatsApp Groups API to create Groups, so you can programmatically create any number of groups when the limit of 256 is reached in a group, using the webhook feature you will be notified on real-time when someone joins or leave the group.
Using the Group Send API you can easily send a message to all the groups easily.
Follow the below steps to get started with WhatsApp Official Account in order to start using Group API