The changes come in the wake of the suicide of at least one teenage user who received online abuse through the site, The Independent reported.
A "report" button will be more prominently displayed and all reports of abuse will be reviewed within 24 hours, co-founders Ilja and Mark Terebin said in a statement.
Hannah Smith, 14, committed suicide after being harassed and bullied online by other users of Ask.fm. She was buried Friday.
The site also has been implicated in the death of Daniel Perry, 17, of Scotland. He killed himself after being blackmailed over Skype conversations, but investigators reportedly found he received messages through Ask.fm telling him to "kill yourself mate" and "you need to let a blade meet your throat."
In their statement, the Terebins said they engaged professional advisers to audit the site and its safety features.
Based on the audit, they said changes were being made to the areas of reporting and moderation, registration and corporate visibility."
Ask.fm said it would limit the number of features unregistered users could access. It also is creating a separate website for parents.