PurposeThe current study seeks to examine the impact of web marketing (through the company's website) on corporate social responsibility (CSR) and firms' performance across companies listed in the Muscat Stock Exchange (MSX), Oman.Design/methodology/approachThis research analyses qualitative and exploratory data taken from companies' website, annual reports (the financial year 2019), Google search and CSR report from 69 out of total 117 listed companies in the MSX to analyze the impact of web marketing on CSR and firms' performance proxied by return of assets (ROA), return of equity (ROE) and Tobin's Q (TQ).FindingsWeb marketing on CSR positively affects firms' performance. Especially, the positive effect of web marketing on firms' performance is stronger for listed companies. Web marketing enhances financial performance proxied by ROA, ROE and TQ.Practical implicationsThe research findings provide new insights that are able to enlighten governing bodies in Oman to make standardized compulsory CSR spending (say, 0.5% on profit after tax) by listed companies in MSX.Originality/valueThis research presents evidence that web marketing on CSR can increase firms' performance and brand image among stakeholders. This is the first study to examine the impact of web marketing on CSR and firms' performance using empirical data in Oman.