To adjust the text size, use the built-in zoom function in the browser. Press Ctrl++ to increase or Ctrl+- to shrink.

Alternatively

Internet Explorer

Select View → Text size→ Select size.

Mozilla Firefox

Select View  → Scaling → Select larger font or less font.

Opera

Select Opera-icon → Page→ Zoom → Select size.

Chrome

Select Tools-icon → Zoom, click + and -.

Safari

Select Page-icon → Zoom → Zoom in or Zoom out.