# Tables in Markdown

> Tables can lose structure when documents are converted or passed to AI tools. Learn how to make row and column boundaries explicit, then verify the result in your target tool.

## Basic syntax

A table is just pipes and dashes: a header row, a divider of hyphens, then your data. Colons in the divider set column alignment.

```markdown
| Metric    | Q2   | Q3   |
|:----------|-----:|-----:|
| Retention | 91%  | 95%  |
| Churn     | 2.4% | 2.1% |
```

| Metric | Q2 | Q3 |
|---|---|---|
| Retention | 91% | 95% |
| Churn | 2.4% | 2.1% |

## Why explicit structure can help

Pipes and header labels make the intended row and column boundaries explicit. That can reduce ambiguity compared with flattening the same data into prose, but it does not guarantee that a model will preserve every relationship. Test complex tables with representative data in the converter, editor, or AI tool you plan to use.

:::tip
**Tip.** Keep one fact per cell. Merged cells and multi-line cells are the most common cause of tables collapsing during conversion.
:::

:::caution
**Not ideal for:** deeply nested or spanned tables. If your source has merged header cells, expect even good tools to need a manual cleanup pass.
:::