Radio Frequency Interference (RFI) is a significant problem for radio astronomy observations, becoming increasingly difficult to mitigate as the number of radio transmitters increases. RFInder is a Python library that uses Casacore to read MS files (the standard format of radio astronomy data) to identify and visualize RFI in their observations. RFInder products include interactive HTML and GIF files that visualize the presence of RFI, the percentage of flagged visibilities due to RFI, and the estimated visibility noise. These visualizations can be used by astronomers to identify and characterize RFI in their observations and to assess the impact of RFI on their data quality. The impact of RFI on an interferometer varies depending on the lengths of its baselines and the observation frequency. RFInder shows the amount of flagged RFI depending on frequency and baseline length, as well as the predicted noise given the flags. RFInder is a command-line tool, available on the Python Packaging Index and GitHub, that integrates seamlessly into pipeline frameworks. CARACal, a radio interferometry data reduction pipeline, leverages RFInder as a component of its toolkit to manage RFI in various MeerKAT Large Survey Programs, thereby providing a layer of quality control for the data processing. RFInder has shown to be a valuable tool for radio astronomers as it can identify trends in RFI levels, such as whether RFI is increasing or decreasing, and new RFI sources over time. This is important because RFI can contaminate radio astronomical signals, reducing the quality of the scientific outcomes.