On May 11, 2017, Pledis Entertainment released a video teaser on Seventeen's Instagram page in preparation for Al1.[1] The video features member Vernon wandering around a deserted road with a compass in his hand. Over the next five days, twelve similar trailers, one for each member, were released on Seventeen's social media accounts.[2] While revealing teasers, Seventeen announced the tour that would accompany the album titled 'Diamond Edge', due to start in July.[3]
On May 17, they revealed the tracklist for the album.[4]
After a month of its release, Al1 sold over 250,000 copies and topped both the weekly Gaon Album Chart for the chart issued on May 27, 2017, and the monthly chart recorded for May.[6][7] The album also debuted and peaked at number two on the World Albums chart for the week ending on May 25, having sold 2,000 units in the United States.[8] The album peaked at number three on Japan's Oricon Albums Chart, the group's highest entry until then.[9]