This is usually caused by adjusting the browser's zoom level. Try making sure your browser is set to 100% zoom (ctrl-0 or cmd-0 in chrome). If that doesn't work, then I'd recommend working through the troubleshooting steps on the wiki . Edit: Of particular interest in those troubleshooting steps is is that only chrome and Firefox are supported by Roll20. Other browsers may work, but no bug fixes can be done for other browsers.