The use of online tools has become more prominent as the global lockdown of education institutions in order to slow the spread of the novel coronavirus pandemic (COVID-19). Teachers all over the world resorted to continue the teaching and learning process online using different online tools. In this study, the preferred online tools, and the relationship between the factors of TESL teachers’ use of online tools and their behavioural intention are investigated. A survey was conducted on 56 Malaysian TESL teachers using purposive sampling technique. The data were collected through online survey questionnaires assigned using Google Forms. The findings showed the top 3 major online tools used by TESL teachers were WhatsApp (80.4%), Google Form (71.4%), while Quizizz and YouTube both achieved a 62.5% among the 56 respondents. Regression analysis showed that Performance Expectancy, Effort Expectancy, Social Influence, and Facilitating Condition were positive predictors of teachers’ Behavioural Intention to use online tools, with Effort Expectancy being the factor that affects Behavioural Intention the most. Since the findings pointed out that Effort Expectancy was the main factor that influences teachers’ online teaching and learning experience, the ministry of education and online tools developers should ensure the online tools are user friendly to reduce teachers’ burden and hence, encouraging the use of online tools.