The Department for Work and Pensions (DWP) now requires all benefit-claiming jobseekers to use its Universal Jobmatch website.
Those who refuse can be sanctioned and lose their benefits.
Universal Jobmatch is an online site that matches unemployed people with jobs.
Employers are encouraged to post all jobs on it, while jobseekers can upload their CV and receive automatic notification when a matching job is posted.
Those who do not have internet access at home will be given it at their Jobcentre where possible.
Minister for Employment, Mark Hoban, said:
"Jobseekers who are serious about looking for work will get all the support they need from us. But in return for receiving Jobseekers Allowance they must prove they are doing everything they can to find a job.
"Universal Jobmatch has already proved a big success in getting people get off benefits and into work, and people are flocking to use it.
"If someone refuses to use a service that already has 460,000 employers posting jobs, you have to ask why - which is why we are now saying claimants must use it."
Last month Costa Coffee reported receiving over 1,700 applications for eight jobs in a new Nottingham cafe.
With many jobseekers requiring entry-level jobs, those companies that post these on Universal Jobmatch are likely to continue to receive huge numbers of applications, including some from unsuitable candidates.