Telegram limits
Sending limits
A bot can send no more than ~30 messages per second and ~20 per minute to one group. The engine keeps the pace and retries on flood wait, so mass publishing only goes through the queue.
What is not allowed
Boosting, inviting by phone numbers, scraping other people’s audiences and messaging strangers are deliberately unsupported: they violate Telegram rules and lead to bans.
Sizes
Post text — up to 4096 characters, media caption — up to 1024, album — up to 10 files, photos up to 10 MB, files up to 50 MB via the dashboard (Bot API serves files up to 20 MB when re-uploading between bots).
two channels free, no card required