Display omitted •Stoke shifted PL emission was exhibited by Gu2PbBr4.•Free exciton emission in Gu2PbI4.•PbI4 octahedron extends 2D chain influenced the light emission of Gu2PbI4.•Pb2+ led 1D confined anionic chain cause the blue shifted PL emission of Gu2PbBr4.•Self trapped states, high degree of distortion in excited lattice induces redshift in PL emission. 1D, 2D behaving systems of Guanidinium lead halides (Gu2PbX4, X = Br−,I−) were synthesized by simple solution technique. The structural and vibrational properties of the compounds are studied using powder X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy. Uv–Visible absorption studies revealed redshift of absorption edge on substituting bromide with iodide in Gu2PbX4. Photoluminescence (PL), PL excitation, Time resolved PL analysis indicates free exciton emission at 518 nm in Gu2PbI4 and self trapped exciton emission at 517 nm in Gu2PbBr4. The mechanism underlying this emission provides fruitful insights in realizing efficient phosphors for solid state lighting applications.