# Previewing
Under-the-hood, Whisk uses a HTTP server to show the contents in previews (both in-app and external). This allows for closer simulation to what content will look like on a server. It only allows connections from your localhost machine by default; see the Preview Server App Security documentation for more details.
# In-App Web Preview
Whisk's Web Preview is powered by WebKit (opens new window), the same rendering engine found within Safari. Because of this, it is fast and standards compliant.
The Options section in the Tools Inspector allows you to edit when you want it to refresh. You can manually reload via the Reload toolbar button, or Command-R.
To debug the Web Preview, you can show the Developer Tools to get access to the Web Inspector.
# Browser Preview
# Desktop Browsers
Whisk can show your document in browsers installed on your computer. It is a good idea to test for compatibility in at least these three browsers:
- Safari
- Chrome
- Firefox
To preview to a browser, hit the Preview button in the Toolbar. The Toolbar has a pop up button that can reveal other browsers. The last one chosen becomes the default for the browser preview, and can be quickly shown via Command-Return.
# iOS Devices
Whisk can also preview to iOS devices directly using the Hype Reflect (opens new window) application. This was originally developed as part of Tumult Hype (opens new window). Read the Hype Reflect documentation (opens new window) to learn more.