This eCPG (expression Catalogue of Protein-coding genes) web tool includes extensive long-read expression data to identify the most abundantly expressed protein-coding transcripts. We identified 18,094 highly expressed representative protein-coding transcripts (Ref-Tx) out of 18,557 human protein-coding genes from GSE192955. A comparison with MANE-select transcripts revealed that 14,546 transcripts in the Ref-Tx list matched those in the MANE-select dataset. This result demonstrates better agreement between long-read transcriptome data and MANE-select transcripts. Given the importance of tissue-specific expression profiles for protein-coding transcripts, we developed this eCPG bioinformatic tool for expression visualization using the long-read dataset as well as GTEx gene expression information.