Use the `font-size` CSS property
Apply `font-size` inline with the `style` attribute
Define `font-size` in a CSS class
Set `font-size` in an external stylesheet
Use relative units like `em`
Use relative units like `rem`
Use percentage values for `font-size`
Increase heading tags such as `
` to `
`
Use the `` tag where supported
Adjust text size with JavaScript by changing `style.fontSize`