Abstract Introduction: Measurement of diet is difficult, and strategies which enable researchers to select the most appropriate dietary assessment tools (DATs) are required. The DIET@NET partnership aimed to create a central resource to improve the quality, consistency and comparability of dietary data. Method: Development of the Nutritools website was divided into 3 strands. 1) Creating Best Practice Guidelines (BPG) which enables researchers to choose the most appropriate DAT for their work. These were generated using the Delphi method which enabled integration of expert views. 2) Creating an interactive DAT e-library, with the DATs being identified through a systematic review of reviews. 3) Creating an online interface (Food Questionnaire Creator (FQC)) between food tables and DATs. Results: Nutritools consists of the interactive BPG comprising 43 guidelines, and a summary of the strengths and weaknesses of the DATs. The DAT e-library provides information regarding the tools and validation study characteristics, and results. Bubble chart and summary plots allow easier comparison between the DATs; and the FQC allows researchers to create new online food questionnaires or use existing DATs identified from the systematic review. Researchers can map their questionnaire to the latest food composition databases. Currently, the FQC only provides UK DATs and databases, however it has the capacity to include international tools and databases.Conclusion: The Nutritools website, www.nutritools.org, provides guidance to researchers undertaking studies that require dietary assessment. By providing guidance and access to validated DATs, the quality, consistency and comparability of dietary assessment in research can be improved. External funding details UK MRC: MR/L02019X/1