Enzymatic hydrolysis is becoming a more commonly used method to create high value products from traditionally low value marine by-products. However, improvement to processing is hampered by a lack of ways to characterize the reaction in real time. Current methods of analysis rely on taking offline samples, deactivating the enzymes, and performing analysis on the products afterwards. Nuclear magnetic resonance benchtop spectroscopy was investigated as a method for online process monitoring of enzymatic hydrolysis. Online and offline NMR measurements were performed for enzymatic hydrolysis reactions on red cod, salmon and shrimp. Both the online and offline measurements were able to follow the reaction process and showed good agreement in their calculated reaction rate. Application of the methodology to several types of raw materials indicates the technique is robust with regards to sample type. Advantages and disadvantages of low-field versus high-field NMR spectroscopy are discussed as well as practical considerations needed in order to apply the method industrially.