The government said the internet was not a lawless environment
The law on "suicide websites" is to be rewritten to ensure people know they are illegal, the government has said.
It follows concerns people searching for information on suicide are more likely to find sites encouraging the act than offering support.
It is illegal under the 1961 Suicide Act to promote suicide, but no website operator has been prosecuted.
The law will be amended to make clear it applies online and to help service providers police the sites they host.
Justice Minister Maria Eagle said there was no "magic solution" to protecting vulnerable people online.
She said: "Updating the language of the Suicide Act, however, should help to reassure people that the internet is not a lawless environment and that we can meet the challenges of the digital world.
"It is important, particularly in an area of such wide public interest and concern, for the law to be expressed in terms that everyone can understand."
Ms Eagle said she hoped the changes would be in force by next year but warned there are "inherent difficulties" with policing "suicide websites" as most are based overseas.
In April, the British Medical Journal reported on a study in which researchers used four search engines to look for suicide-related sites.
The three most frequently occurring sites were all pro-suicide, prompting researchers to call for anti-suicide web pages to be prioritised.
An outright ban on suicide sites would have been unworkable, according to the Samaritans.
But the support service's public affairs manager, Anthony Langan, said the change in the law would be "a strong step" towards making the internet safer.
"The next step must be to understand how and why people use the internet to find out about issues like suicide, and develop our services in response to the results," he added.
Paul Kelly, trustee of Papyrus, a charity which works to tackle youth suicide, welcomed the move, saying it would encourage ISPs to be more active in taking down illegal content.
He urged ministers to tighten the law so it was harder for websites to publish material "promoting" suicide.
"In practice it's very easy to encourage others to take their own lives and it's very unlikely they are going to be prosecuted in a court of law," he said.
Since 2007, 23 young people have killed themselves in and around Bridgend in south Wales.
The constituency's MP, Madeleine Moon, said she welcomed "simplifying and modernising the language of the law" to make it "capable of reflecting the new ways of communicating and accessing information".