Web Interface

The AJAX-based web interface is used for the configuration of devices and sensors, as well as the review of monitoring results. The web interface is highly interactive and uses AJAX ("Asynchronous Javascript and XML") to deliver a powerful and easy-to-use user experience. While the user is logged in, the data on the screen is permanently refreshed (via Ajax calls) so it always shows the current monitoring results (refresh interval and method can be set by the user).

When you open the web interface, you will see PRTG's welcome page as default. This page helps you to add sensors manually, perform an automatic network search, review results, download the Windows-GUI or iPhone applications and get further help and support.


By clicking on "Review Results", you enter the tree-like device view which will be your starting point for everyday use. Please have a look at this screenshot of PRTG's device page in the web interface:


The main layout consists of a status bar at the top, the header area with the main menu and quick-search box below it and, finally, the main page content (all these elements are described in the next section).

When you navigate through PRTG's web interface you will always use one of the following five navigational paths:

  • The main menu provides access to many important aspects of the software.
  • The quick search is often the fastest way to navigate to an object.
  • Using the page's tabs, you can switch between various sub-pages for an object.
  • Many objects offer a context menu that will pop up when you right-click them.
  • And, finally, you are able to drill down into the object hierarchy of probes, groups, devices and sensors in the object tree shown above by merely clicking an sub-object of the currently displayed object (e.g. a sensor on the device page).

These five navigation paths put PRTG's complete functionality at your fingertips. Quite likely you are already familiar with these techniques from many other websites and web-based user interfaces.

Let's have a detailed look at PRTG's web interface -building blocks:

Global Status Bar


This bar is always shown above all pages. It shows the aggregated status of all sensors you have configured for monitoring. Depending on the sensors' status you will see colored squares with numbers (in the screenshot above, 23 sensors are in error (red), 3 show a warning state (yellow), 95 sensor show "OK" status (green), 129 sensors are paused (blue) and 40 sensors have an "Unusual" status (orange).

The four graphs show the number of alarms as well as three "Index" graphs for response time, CPU load und bandwidth traffic usage over the last 24 hours. These graphs are "index" graphs, similar to a stock index. The values are based on the readings of all sensors, groups or devices. They are computed by using statistical computations and by comparing the values to the highest and lowest readings ever recorded. For example, a CPU Load Index value of 90 % means that the average CPU load for all CPU sensors of your current configuration lies at 90 % of the highest ever measured CPU usage value.

Website Header Area, Search Box and Main Menu


Navigating through the web interface is performed using the main menu. Please take a few minutes to familiarize yourself with all menu items and sub-items. Menu item "Alarms" is highlighted with red color whenever there is an alarm. "Logs" and "ToDos" are highlighted with blue color if new messages or new ToDos are available. To search for any monitoring object, simply enter the name, part of the name, an IP address, a DNS name or a tag in the search box on the right and hit the enter key. A web page with all items that fit the search term will be returned - even displaying online help articles.

Page Header and Tabs


The individual page content starts below the website header area. Depending on the page's content you will see a menu and a few action links on the right. "Breadcrumbs" that will always show the path back to the homepage can be found below the heading. The yellow boxes display context sensitive help which can be hidden by clicking the small "x" on the top right.

Many pages have a tab-like interface. Using these tabs you can navigate to various sub-pages for an object:

"Overview" tab

All monitoring objects offer this tab providing a quick overview of all parameters and statuses.

"Live Data", "48 Hours", "30 Days", "365 Days" tabs

These three or four tabs show the group's, device's or sensor's historical graphs and data tables (note: live data is only available for sensors).

"Historic Data"

Shows an assistant to review or download historic sensor data. This function is available in "Sensor Details" view. See below for further explanations.

"Alarms" and "Log" tab

Shows a list of current alarms and historic events for an object (and its child objects).

"Settings" and "Notifications" tab

Allows you to edit an object's settings and notifications. The available settings depend on the kind of object you are editing.

"Channels" tab

This tab is available for sensors. Each sensor has one or more channels on which it gets data. In this tab, you can configure how a channel's values are processed. See Edit Sensor Settings for more details.

"Comments" tab

Provides a notepad for your own comments.

"History" tab

Shows a lifetime log for each object (who created it, who edited it etc.).

Please note that you will also see other tabs for other objects.

Overview Page for Groups, Devices and Sensors

Have a look at the following three screenshots showing the "Overview" tab of a group, a device and a sensor:

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You can see that all three share a common layout:

  • On the upper left you have the object's name, basic settings and sensor status.
  • Below that there is a list of child objects (devices for a group, sensors for a device and channels for a sensor).
  • On the right there are three or four graphs showing recent history. To zoom into a graph, simply click on it (or choose the appropriate tab).

For sensors you will see four graphs that show all "channels" of the sensor for the last 2 days, last 30 days and last 365 days plus a live graph. For groups and devices there are three graphs that show the alarms, CPU load index, traffic index and response time index (explained above) for the last 2 days, last 30 days and last 365 days. Details about index calculation are available in the Paessler knowledgebase at http://www.paessler.com/support/kb/prtg7/how_prtg_computes_index_graphs.

Box with Alerts

Every time a new event occurs while you are logged into the web interface of PRTG Network Monitor a box with alerts will show up in the lower right corner of your browser window:


Please keep an eye on these important messages which PRTG will display as it discovers changes in the network or requires your attention for other reasons. Simply click the text inside the colored bar to navigate to the detailed information page or click one of the "x" symbols to dismiss and hide the alert. In the user account settings you can control which events actually display the popup.

Context Menus

Although context menus may seem unusual for a web-based application, they are the key to user interface's ease of use. Almost all objects that appear as links in the user interface will show a context menu when your right-click them. Using it, you can access every relevant function of an object. Here are three sample context menus (for group, device and sensor). They are similar to any other context menu in a Windows environment:

Note: If you want to access the browser's own context menu, hold the CTRL key down when right-clicking.

Working with Lists and Multi Edit Menus

Throughout the web interface often you will see lists of items, e.g. sensors, devices, maps, reports etc. All these lists provide common functionality. Here are two sample lists (sensors and logs):



The following functions are available for lists:



What it does



Use the small triangular icons at the top or bottom to walk through a list page by page.



You can re-sort a list by clicking the header of the column you want to use as sorting index.

Date Range


When viewing log lists, you can click on "Date Range" to change the desired date range.

Item Count


Some lists offer the possibility to change the number of entries in the list by clicking on "Item Count".

Additionally some lists offer a column of checkboxes. The checkboxes are used to select two or more items from the list and work with the selected items. As soon as you select one or more checkboxes, an additional, green colored menu will show up:


Depending on the object type different functions are available. Some frequently used functions are available as quick buttons, other functions are available in the drop down menu:

Reviewing Historic Data

Additionally to sweeping reports that additionally can be scheduled for regular execution (see section Reports), you can view a report of the historic data for each single sensor, on demand.  Additionally, you can also export this data and download it for further processing in external applications. To get to the Historic Data reports, choose a sensor, right-click on it and from the context menu, select "Details...". In the sensor's detail view, click on the "Historic Data" tab to start the review.

You can select the following options:

  • Start: Enter the start date and time of the data you want to review.
  • End: Enter the end date and time of the data you want to review.
  • Average Interval: With this option, you can activate and set up averaging. Select an interval for which the average value should be calculated. You can choose between "No Interval" (no averaging will be performed), a few seconds, minutes, hours, or a whole day. A smaller interval will result in a more detailed report for this sensor. The best settings for you vary, depending on the Scanning Interval of the sensor, the selected date period and, of course, the intended use for the report. It might be useful to try different settings to see what the results look like.
  • File Format: This is the output format for the report. You can select between an HTML web page, an XML file and a CSV file (for import in Microsoft Excel, for example).
  • Include Percentiles: Activate this option to add a percentile value to the report. See section Calculating Percentiles for more information.

Click on "Start" to generate the Historic Data report. Please note: Depending on the selected output format, either a new browser window or tab will open and show an HTML web page, or the browser will start the download of an XML or CSV file. If you just generated an HTML web page report and it is still opened while you are generating another, no new browser window or tab will open, but instead the existing HTML web page will be refreshed and it will show the most recent report.


Keywords: Web Interface,Main Menu,Quick Search,Search Box,Tabs,Context Menu,Global Status Bar,Status Bar,Website Header Area,Search Box,Quick Search,Main Menu,Page Header,Lists