Data outliers pose significant challenges in data processing and machine learning (ML) by distorting outcomes and leading to suboptimal model performance, making outlier detection an essential step in any data pipeline. The text explores various outlier detection methods, such as Z-score, clustering, and interquartile range (IQR), which help identify anomalies in datasets. Additionally, it reviews several outlier detection tools, including Encord Active, Lightly, Aquarium, Voxel51, Deepchecks, and Arize, highlighting their features, benefits, and best-use scenarios. These tools employ advanced techniques to streamline data processing and ML workflows, offering functionalities like active learning, data curation, model monitoring, and anomaly detection across diverse data types. Choosing the right tool involves considering factors like ease of use, scalability, flexibility, visualization capabilities, and integration with existing systems to ensure accurate statistics and reliable model performance.