Governments are wrestling over measures to better control illegal or dangerous content on social media, with the European Union set to unveil its own package on Tuesday.
Britain's measures, which will be introduced in legislation next year, could lead to blocking sites that break the rules.
Dowden said criminal sanctions for directors remained an option that could be enacted through secondary legislation if companies
did not take the new rules seriously.
"These measures make this the toughest and most comprehensive online safety regime, and they will have a clear and immediate effect," he told lawmakers on Tuesday.
Popular platforms will also be required to have clear policies for content that, while not illegal, could cause harm such as disseminating misinformation about Covid vaccines.
said it had long called for government and industry to work together on the "complex challenge" of protecting people from harm without undermining freedom of expression.
"We already have strict policies against harmful content on our platforms, but regulations are needed so that private companies
aren't making so many important decisions alone," said Rebecca Stimson, the head of UK public policy.
Fast growing video-sharing platform TikTok, owned by China's Bytedance, said it was looking forward to working with the government to continue to strengthen online safety.
"At TikTok, safety isn't a bolt-on or a nice-to-have, it's our starting point to building a creative, diverse community," a TikTok
Ben McOwen Wilson, managing director of Google's YouTube UK, said the safety of its online communities was its top priority and that it had not waited for legislation before acting.
"We have worked with industry, community groups and the government to tackle harmful content," he said.
British media regulator Ofcom will be given the power to fine companies
up to 18 million pounds ($24 million) or 10 per cent of global turnover, whichever is higher, for breaking the rules.
It will also be able to block non-compliant services from being accessed in Britain.
Online journalism and reader comments on news publishers' websites will be exempt to safeguard freedom of expression.
Business Standard has always strived hard to provide up-to-date information and commentary on developments that are of interest to you and have wider political and economic implications for the country and the world. Your encouragement and constant feedback on how to improve our offering have only made our resolve and commitment to these ideals stronger. Even during these difficult times arising out of Covid-19, we continue to remain committed to keeping you informed and updated with credible news, authoritative views and incisive commentary on topical issues of relevance.
We, however, have a request.
As we battle the economic impact of the pandemic, we need your support even more, so that we can continue to offer you more quality content. Our subscription model has seen an encouraging response from many of you, who have subscribed to our online content. More subscription to our online content can only help us achieve the goals of offering you even better and more relevant content. We believe in free, fair and credible journalism. Your support through more subscriptions can help us practise the journalism to which we are committed.
Support quality journalism and subscribe to Business Standard.