In response to its rise in popularity, the app added a feature that allows users to import their chat history from WhatsApp, from both individual and group discussions. This means if you're making the switch, you won't have to lose past conversations and you can continue from where you left off, as long as each WhatsApp user has a Telegram account.
On iOS, the feature arrived with Telegram's version 7.4, and it's available for Android, too.
Chat histories can also be imported from Line and KakaoTalk.
How to import your chat history
To move a chat from WhatsApp on iOS, open the Contact Info or Group Info page, tap Export Chat, then choose Telegram in the Share menu. WhatsApp for iOS also lets you export chats directly from the chat list. To do so, swipe left on a chat, then choose '…' > Export Chat.
On Android, open a WhatsApp chat, tap on the three dots and choose More > Export Chat, then choose Telegram in the Share menu.
You can choose to import your chats with or without shared media.
The messages and media don't need to occupy extra space on your phone, either, says Telegram.
"Older apps make you store all data on your device – but Telegram can take up virtually no space while letting you access all your messages, photos and videos anytime you need them."
To free up space and control your cache size, Telegram advises doing so in Settings > Data and Storage > Storage Usage.
Any imported messages will have a small "imported" label on them and will tell you when they were sent, and when they were moved over to Telegram. These can be seen by all chat participants.
It's also useful to note that messages will appear in the order in which they were imported, rather than when they were originally sent.