Fluorimeters are widely utilized for the quantitation of biological compounds in solution, with applications ranging from environmental/agricultural water monitoring to DNA sequencing. These devices measure fluorescence by exciting a sample with an integrated light source and collecting the emitted light using either filtered detectors or embedded spectrometers. Historically laboratory fluorimeters utilized spectrometers due to their high resolution and sensitivity. In contrast, portable and handheld fluorimeters were filter-based to reduce the unit’s overall size and power consumption. Recent developments in spectrometer miniaturization, such as the AvaSpec-Mini from Avantes have significantly reduced the barriers to full-spectrum analysis, allowing for laboratory-grade measurements in the field. In this application note, we will explore the benefits of miniature spectrometers for portable fluorimeters by briefly reviewing the fundamentals of fluorescence spectroscopy with a particular emphasis on the impacts on fluorimeter design.