Plant bioactive-based nanomaterial is a rapidly growing class of nanostructures with immense potential in field of medicine, agriculture cosmetics, environmental remediation, food industry, bioengineering and electronics. These bio-nanomaterial are highly complex and diverse as their potential application are in synergy with their attributes and influence nanomaterial properties such as size, morphology, chemical composition, surface charge, and thermal. Here we discuss traditional and advanced techniques for characterizing plant bioactive-based nanomaterial, including UV-Visible Spectroscopy for monitoring nanoparticle formation through Surface Plasmon Resonance (SPR) peaks, Fourier Transform Infrared (FTIR) Spectroscopy for functional group identification and to determine their reactivity and biocompatibility where DLS and zeta potential measurements determine nanoparticle size distribution and colloidal stability, critical for drug delivery and environmental remediation. Thermo gravimetric Analysis (TGA) is used to investigate the thermal properties along with the organic content of the nanoparticles, while TEM and SEM provide high resolution imagery of nanoparticles. Using advanced structural analysis methods, such as X-ray Diffraction (XRD) for crystallographic studies, Atomic Force Microscopy (AFM) for surface topology, and X-Ray Photoelectron Spectroscopy (XPS) for surface chemistry, gaining a more complete understanding of how bioactive compounds interact with nanoparticles. In addition, Nanoparticle Tracking Analysis (NTA) for monitoring size and concentration, Scanning Mobility Particle Sizer (SMPS) for determining precise size and concentration, Brunauer-Emmett-Teller Analysis (BET) for measuring surface area, and Surface-Enhanced Raman Spectroscopy (SERS) for molecule identification. These high throughputs and in situ methods speed up the characterization, enabling real time monitoring of nanoparticle synthesis to the meet the standards of modern applications.