As Post-Hardcore steadily gained mainstream influence in the 2000s through the popularization of Emo-Pop and the Warped Tour scene, artists such as Anthony Green and The Fall of Troy began to lead the sound in a more experimental and progressive direction while still retaining the increased commercial appeal of contemporary post-hardcore acts. This form of the genre would continue to develop before cementing its own niche in the community by the 2010s, with fans of guitarist Will Swan dubbing the subgenre after his name.

Greater focus is given to clean vocals, largely sung in higher registers with a style reminiscent of Green's work in Saosin and Circa Survive as well as Claudio Sanchez of Coheed and Cambria. Unclean or screamed vocals still remain present in Swancore, though certainly with less of a focus placed on them and other more aggressive aspects found in early Hardcore . Bands who do employ harsher vocals, however, also do so in a style reminiscent of early 2000s post-hardcore as opposed to the more guttural or high-pitched screams found in the concurrently popular sound of Metalcore.

Retaining earlier forms of post-hardcore's instrumental complexity, bands also began to incoporate cleaner and more technical instrumentation in the vein of Progressive Rock and Progressive Metal. Key figures fleshing out this intersection early-on included acts like The Sound of Animals Fighting, drawing the sound further from its hardcore origins and increasing intricacy. Further influence from progressive rock is also seen through the use of guitar and bass pedals, including pitch-shifting, delay, and fuzz, as well as, sometimes, inclusion of violin, flute, and other classical instrumentation. Another integral origin of the progressive post-hardcore sound is Math Rock, especially through uncommon time signatures and layered guitar riffs, though with less of a focus on dissonance as found in Noise Rock or Mathcore and instead on a cleaner, more accessible sound sometimes akin to Math Pop.

Moving into the early 2010s, progressive post-hardcore evolved into a more modern sound. With the creation of Swan's label Blue Swan Records in 2013, the subgenre was further streamlined and saw greater distinction from both its mid-2000s origins as well as other post-hardcore outfits that leaned towards the popular sounds of metalcore and Trancecore. Artists signed to Blue Swan such as Kurt Travis and Sergio Medina often collaborate across bands, lending to the subgenre's distinct and consistent sound actively attributed to Swan's work in Dance Gavin Dance. Bands signed to labels such as Rise Records and Equal Vision Records also employ the Swancore sound, though often with a greater emo-pop or Alternative Rock touch.