“Everything is finished in Raqa, our forces have taken full control of Raqa,” SDF spokesman Talal Sello told AFP.
“The military operations in Raqa have finished, but there are clearing operations now under way to uncover any sleeper cells there might be and remove mines,” he added.
“Soon there will be an official statement announcing the liberation of the city.”
The city’s capture comes after the SDF on Tuesday seized the last two remaining IS positions in Raqa, the national hospital and the municipal stadium.
On Monday, the SDF had taken the infamous Al-Naim traffic circle, dubbed the “Roundabout of Hell” by residents under IS rule because the jihadists used it for public beheadings and crucifixions.
The SDF, an alliance of Kurdish and Arab fighters, began their operation to drive IS from Raqa last November, spending months encircling the city before breaking into it in June.
Over the course of four months, they captured some 90 percent of the city, but operations were paused last week to allow local officials to negotiate the evacuation of thousands of trapped civilians.
Under the agreement, several hundred Syrian IS fighters and family members also left remaining jihadist positions, leaving only an estimated 300 foreign fighters in the city.
IS captured Raqa in 2014 and transformed it into the de facto Syrian capital of its self-styled “caliphate” in Syria and Iraq.
The city became synonymous with the worst of the group’s abuses, as well as a planning centre for jihadist attacks abroad.