Two benzothiazole based Schiff bases 5-(diethylamino)-2-(((6-methoxybenzo[d]thiazol-2-yl)imino)methyl)phenol (probe 1) and N-(4-(dimethylamino)benzylidene)-6-methoxybenzo[d]thiazol-2-amine (probe 2) were efficiently synthesized and structurally characterized. Molecular structure of probe 1 is obtained by single crystal X-ray analysis. The presence of hydroxyl substituent on phenyl moiety makes probe 1 as ESIPT (Excited State Intramolecular Proton Transfer) probe and the absence of hydroxyl on phenyl moiety differs probe 2 as PET (Photo Induced Electron Transfer) probe towards sensing of H+ ions. Probe 1 selectively detects H+ ions colorimetrically with reversible changes on adding a base like TEA. Besides H+ ions, probe 2 detects Cr(III) ions with a colorimetric response. The addition of TEA leads to reversible changes with primary protonation and these changes were irreversible with second protonation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim