Bar Chart

A bar chart compares a value across distinct categories by drawing one bar per category, where the bar's length encodes the number. Because our eyes judge length precisely, it is the most reliable chart for comparisons like sales by region, votes by party, or visits by browser.

Two rules make or break it. First, the value axis should start at zero — bars are read by length, so cutting off the bottom exaggerates differences and misleads. Second, sorting bars by size (rather than alphabetically) usually makes the ranking far easier to read. A pie chart tries to do the same job with angles, which the eye reads worse, so a bar chart is often the better choice.