People judge charts in half a second — long before they read a number. These nine habits separate charts that persuade from charts that get screenshots and doubt.
- Start the y-axis at zero (for bars). Truncated axes are the #1 credibility killer. Line charts may start elsewhere when the story is change, not magnitude.
- Write a title that states the finding. "Churn fell 40% after the redesign" beats "Churn by month, 2024-2026". The chart answers; the title asks the question.
- Limit colors to one accent. Highlight the bar that matters; gray the rest. Rainbow palettes imply meaning that usually isn't there.
- Label directly when possible. Value labels on bars and points beat forcing readers to squint at an axis.
- Cap your categories. 5-12 bars, 3-6 pie slices, 5-15 line points. More than that, aggregate into "Other" or split charts.
- Sort with intent. Bars sorted by value (not alphabet) make the ranking instantly visible. Time series stay chronological.
- Round numbers on axes. "1.2k / 2.4k / 3.6k" reads faster than "1237 / 2441 / 3612".
- One chart, one message. If you're explaining two things, use two charts.
- Export at 2× resolution. A crisp chart signals care; a blurry one undermines the data behind it. (GPT Chart exports at 2× by default.)
Apply all nine in one place: paste your data into the GPT Chart tool, pick the right chart type, choose a restrained palette, and download a crisp PNG. That's a deck-ready chart in under a minute.