The article reviews the properties and experimental tuning methods of planar hyperbolic polaritons in 2D van der Waals (2D vdW) materials. Planar hyperbolic polaritons are anisotropic electromagnetic modes mediated by phonons, plasmons, or excitons, which have attracted significant attention due to their fundamental physics and potential applications in nanophotonics. The review highlights the prevalence of such media in biaxial and uniaxial 2D and 1D vdW crystals and discusses the untapped opportunities they offer for functional polaritons, such as ferromagnetic, ferroelectric, and piezoelectric properties. The article also explores the unique propagation characteristics of these polaritons, including ray-like propagation and magic angles corresponding to topological transitions. Experimental observations of planar hyperbolic polaritons in materials like α-MoO3, WTe2, and black phosphorus are discussed, along with methods for tuning their properties through heterostructures, strain, electrostatic gates, intercalation, nanostructuring, and hypercrystals. The potential technological applications of these polaritons, including quantum and spin photonics, thermal management, sensing, subwavelength focusing, transformation optics, and polarization engineering, are also covered.The article reviews the properties and experimental tuning methods of planar hyperbolic polaritons in 2D van der Waals (2D vdW) materials. Planar hyperbolic polaritons are anisotropic electromagnetic modes mediated by phonons, plasmons, or excitons, which have attracted significant attention due to their fundamental physics and potential applications in nanophotonics. The review highlights the prevalence of such media in biaxial and uniaxial 2D and 1D vdW crystals and discusses the untapped opportunities they offer for functional polaritons, such as ferromagnetic, ferroelectric, and piezoelectric properties. The article also explores the unique propagation characteristics of these polaritons, including ray-like propagation and magic angles corresponding to topological transitions. Experimental observations of planar hyperbolic polaritons in materials like α-MoO3, WTe2, and black phosphorus are discussed, along with methods for tuning their properties through heterostructures, strain, electrostatic gates, intercalation, nanostructuring, and hypercrystals. The potential technological applications of these polaritons, including quantum and spin photonics, thermal management, sensing, subwavelength focusing, transformation optics, and polarization engineering, are also covered.