KRAB ZNF explorer is a web-based tool for comprehensive characterization of the mRNA expression status of KRAB-ZNF transcription factors in the data from The Cancer Genome Atlas study. Key functionalities cover a comparative analysis of KRAB-ZNF expression between normal and cancer tissues, an association of KRAB-ZNF expression with various pathological features, including survival analysis, association with global DNA methylation status, analyses of KRAB-ZNF isoform expressions and analysis of KRAB-ZNF levels in normal tissues.