Review: Free and low-cost Wi-Fi stumblers for the Mac

On the bottom of the Discover screen, you can toggle scanning on and off, adjust scanning interval, and click the Details button as an alternative to double-clicking a network to bring up the graphs and additional details. On the bottom right, you can also type in a search phrase to filter the list of networks.

On the Survey screen of NetSpot you can perform map-based surveys in order to generate heatmaps to visualize signal coverage and other parameters on a floor map of your choice. Keep in mind, the free edition has many limitations, including only capturing open or unsecured networks, surveying one zone or floor plan per project, and only two visualizations are given at the end.

Setting up a survey is straightforward. You select a floor plan map, set calibration, configure which networks to capture, and set scanning type. Like most other surveying programs, you walk around the area to be surveyed while clicking where you are on the map.

Once you’re done, you can select which SSIDs to include in the visualizations from the list on the left. On the bottom you see the color-coded legend and can select other visualizations to view on the map. In the free edition, you only have the signal and SNR visualizations.

In the PRO edition, you have many more visualizations to choose from: quality of access points, noise level, signal-to-interference ratio, frequency band coverage, PHY mode coverage, and troubleshooting. The PRO edition also adds visualizations for a couple of different download and upload speeds, if active scanning was selected.

On the top of the Survey screen, you see the same buttons on the top. The Export button allows PRO or Enterprise users to generate reports and heatmap images.

From the Survey menu on the NetSpot toolbar, you save your survey project and manage other project and zone settings, which are mostly available only in the PRO or Enterprise editions, though the Free edition does allow basic saving of the survey project. From the NetSpot toolbar you can also access the Preferences of the application, which includes various settings for the discover and survey functions.

WiFi Explorer

WiFi Explorer is a general Wi-Fi stumbler developed by Adrian Granados, available for $6.99 via the App Store. It runs on Mac OS X 10.7 and later. It only works with the internal AirPort card; USB Wi-Fi adapters aren’t supported.

Once you open WiFi Explorer, you immediately see the list of SSIDs on an attractive GUI. You’ll see the usual network details, including noise and SNR, and can add/remove more details via right-clicking on the columns. By default, the signal levels are shown in percentages, but you can change to dBm via the Preferences.

Selecting a network from the list will show further details, including a graph for that particular SSID, on the bottom portion of the screen. You can toggle between signal, signal and noise, and SNR for the graph. All graph options include a small convenient secondary graph on the right showing the levels on other access points operating on the same channel, if there are any.

On the bottom portion of the screen, you can also tab through additional screens. The Signal Strength tab shows a graph of the signals from all access points. The Channels tab shows a channel graph of both frequency bands. The Advanced Details tab shows additional details on the network currently selected from the list above. This includes supported rates, HT capabilities and operation, and other advanced details.

On the left portion of the main screen, you can utilize their pre-configured filters. For instance, you can choose to view only access points with a particular SSID, those using a certain 802.11 standard, SSIDs from a particular radio, SSIDs from access points using a certain vendor, or SSIDs that are within a defined signal range.

+ ALSO ON NETWORK WORLD Review: Android-based Wi-Fi stumblers +

On the top of the screen you can also filter based upon open, secure, or ad-hoc networks. You can also type into the text field to quickly filter upon a desired SSID name. Additionally, on the top of the screen you can toggle scanning on and off, and see the connection details for the AirPort card.

From the toolbar, you can access the application Preferences, which include scanning settings, columns to be displayed, and advanced settings. From the File menu, you can open, save, and export the network details. Accessing the Help brings up a traditional help window, containing great documentation, which is also accessible offline. It includes some good general Wi-Fi troubleshooting information as well.

WiFi Scanner

WiFi Scanner is a general Wi-Fi stumbler with network scanning capabilities as well, available from the Apple App Store for $6.99. It is developed by AccessAgility, which also offers a cloud-based Wi-Fi monitoring solution and is working on a desktop version of their scanner for Windows too. Currently, their WiFi Scanner application runs on Mac OS X 10.6 and later, but for all features you must have 10.7 or later.

When you open WiFi Scanner, you’ll see the network list and all their details right away on the main screen. It includes all the usual SSID and network details, with signal and noise levels shown in dBm values.

On the bottom portion of the main screen, you can tab between different pages of information. First is the SSID Details tab, showing the same details from the list along with a couple more and a signal/noise graph with SNR reading as well.

The RSSI vs. Time tab shows a signal graph of all SSIDs, with the selected network conveniently highlighted. The 2.4 and 5 GHz tabs show channel graphs of their respective band. The Signal Rank tab shows a bar chart of the SSID signals from best to worse. The Speed Test tab allows you to run download and upload bandwidth tests on the network you’re currently connected to and then tracks the results on a graph.

On the top portion of the main screen, you find some scanning and filtering settings. You can optionally stop scanning and then restart to capture multiple scanning sessions that you can switch between from the left portion of the screen, which keeps a running list of the sessions.

On the very top of the screen, you find two other main tabs. The Connected SSID tab shows you basically the same information as the SSID Details sub-tab, but shows additional security details and a larger graph. The Who’s On My Network tab, you can perform IP scanning to see the list of devices and IP addresses detected on the network you’re currently connected to. You can then click a device to name it and give it an icon and also view it’s Media Access Control address, hostname, vendor, and last and first seen date/time.

From the WiFi Scanner toolbar, you can access the Preferences. From there you can customize the details shown on the network list and graphs, customize speed test settings, define the IP address range for the IP scanner, and configure a remote GPS connection.

On the File menu of the toolbar you’ll see several exporting and reporting options to save your results in CSV or HTML files, optionally with the graph images as well. However, keep in mind you can’t save the data and re-open with the WiFi Scanner application. The Help shortcut brings up thorough and useful documentation, but it’s not available offline, though you can download from their website.

Eric Geier is a freelance tech writer—keep up with his writings on Facebook or Twitter. He’s also the founder of NoWiresSecurity providing a cloud-based Wi-Fi security service, and On Spot Techs providing RF site surveying and other IT services.