Gloomcore is an internet aesthetic primarily composed of liminal and dreamlike imagery of forests, beaches, and other similar landscapes. It often expresses elements of the odd and otherworldly through these liminal/dreamlike themes and emphasizes the connection between the natural and the surreal. Gloomcore is primarily an aesthetic of visuals, not fashion or music. Individuals who partake in Gloomcore often enjoy the strange as a whole, and find beauty in silence: skies, coastlines and forests, all shrouded in fog.

Gloomcore's visuals adhere to two specific guidelines. The first is that the visuals are to involve natural or semi-natural landscapes; the second is that the visuals must retain a dreamlike and/or liminal quality to them. Overall, the visuals should give off a tranquil (yet perhaps still on edge) sort of emotion to the viewer. Common visuals include:

Gloomcore has much looser guidelines to its fashion than other aesthetics have. It encompasses several overall qualities, and within those qualities, can have much variation. The fashion takes inspiration from the fashion styles associated with Goblincore and Forestpunk , as well as general alternative fashion.

Overall, the fashion is meant to be comfortable and often warm, since the climates seen in the visuals are often quite cold. Items from each category (tops, bottoms, etc.) are commonly layered on top of each other rather than worn alone. Gloomcore fashion mainly utilizes muted shades of green, brown, gray, and sometimes black, similar to the visuals, but may occasionally contain a "pop" of a different color. The silhouette is meant to be androgynous, oversized, and boxy. The fashion mostly uses matte fabrics, mostly with a smooth texture, though occasionally with a more "rustic" texture. The materials used are usually natural fibers such as cotton, as well as materials like sheep's wool and real leather, since these materials are more sturdy than synthetic wool and pleather. The fabrics used are rarely printed unless they're pieces such as skirts.

Outfits may include any of the following pieces from each of these categories. Pieces outside of these categories may also be used but are rarer to see.

Gloomcore as a whole is related to the concept of being at peace in places that are not truly peaceful, so activities that help one achieve this feeling are the most common among those who partake in the aesthetic. These activities include:

Because of the nature of this aesthetic, the music associated with Gloomcore is soft and dreamlike, while also involving elements related to nature and occasionally having lyrics related to activities associated with Gloomcore. Most Gloomcore music is mysterious and delicate with ambiance from nature sounds (e.g. rain), perfect for meditating or "glooming" to.