List of Chat Widget for website

Freemium

1. Chatango
2. tawk.to
3. Purechat
4. Widgetwhats
5. jivochat
6. purechat
7. tidio
8. chaport
9. chatra.io
10. smartsupp
11. Freshchat
12. clickdesk
13. liveagent
14. drift
15. mylivechat
16. userlike
17. crisp.chat
18. comm100

Premium 

1. olark 
2. chatbot
3. helpcrunch
4. snapengage
5. kayako
6. intercom
7. livechat
8. velaro
9. liveperson
10. livehelpnow
11. websitealive

Source:

• https://www.websitetooltester.com/en/blog/best-livechat-software/
• https://www.crazyegg.com/blog/live-chat-software-solutions/
• https://www.wpbeginner.com/showcase/7-best-live-chat-support-software-for-your-wordpress-site/