#YSK you can browse many genomes (including the human genome) base by base in your web browser: http://genome-euro.ucsc.edu/cgi-bin/hgTracks?db=hg38&lastVirtModeType=default&lastVirtModeExtraState=&virtModeType=default&virtMode=0&nonVirtPosition=&position=chr1%3A1%2D248956422&hgsid=234349412_5UAE4f0bbj8opTwOqN3kzClh2eFa