DNA strands can be analyzed at the single-molecule level by isolating them inside nanoscale holes. The strategy is used for the label-free and portable sequencing with nanopores. Nanochannels can also be applied to map genomes with high resolution, as shown by Jeffet et al. in this issue of ACS Nano. Here, we compare the two strategies in terms of biophysical similarities and differences and describe that both are complementary and can improve the DNA analysis for genomic research and diagnostics.