Yes, both Twilio Flex and SendBird offer a Free Trial.
Twilio Flex is designed for Large Enterprises and Medium Business.
SendBird is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Pricing for Twilio Flex Starts at $1/User whereas for SendBird Starts at $399/Month.
Some top alternatives to Twilio Flex includes CometChat, CloudTalk, Five9, 3CX, Genesys PureConnect, MSG91, Infobip, Cloudonix, CommPeak, CloudContactAI and Messenger Communication Platform.
Some top alternatives to SendBird includes CometChat, Plivo, Twilio Flex, MessageBird, MSG91, Infobip, PubNub, Stream Chat, ZEGOCLOUD and Messenger Communication Platform.