Your iPhone’s hidden field testing mode finally lets you bookmark network measurements for ease of use

If you’ve ever used your iPhone’s hidden field test mode to view signal strength in decibel-milliwatts, locate the tower you’re connected to, or determine the radio frequency you’re using, you no longer need to dig through all the confusing-looking data every time you need to check. Apple updated the Field Test interface in iOS 15, and one improvement gives you more control over the dashboard.

From the beginning, Field Test Mode has been a hidden feature of the iPhone, primarily used by radio technicians, network technicians, and field operators to measure network performance and diagnose any potential problems. While most of the information displayed in Field Test Mode looks like technical chatter, there are a few points that regular iPhone users may find useful.

Some iPhone models have received a much-needed updated UI for Field Test Mode in iOS 14, and this UI is confirmed by Apple’s new iOS design language. He introduced the Dashboard, the home page for the most valuable data users might need, and moved the main menu to the All Metrics tab. You can swipe left on any data point in the toolbar to delete it, but iOS 14 didn’t let you add your favorites to the list. Apple has now fixed the issue in iOS 15.

To open Field Test mode on your iPhone, enter the dial code *3001#12345#* on the Phone app keypad, then press the green call button. The code should redirect you to the toolbar in the hidden FTMInternal app.

To remove data points from the dashboard, click Manage Dashboard, then swipe left to the edge of the screen, or swipe left and click the Delete button. When you’re done, tap the X icon.

If you have an additional cellular plan on your iPhone, it will have its own toolbar tab with its own set of data points for easy access. To remove items from the list, go to this tab and do the same as for the first cellular plan.

Now, to add data points to your dashboard, select your carrier network, if you have more than one cellular plan, then click the menu icon that looks like a bulleted list. This will take you to All Metrics where you will see sections like RAT, LTE and MISC.

Tap an item in one of these sections and you’ll see bookmark icons next to each of the data points. Tap a bookmark to add it to your favorites and it will appear in your control panel.

Similarly, you can also click a completed bookmark to remove that data point from the toolbar. So, there are two ways to delete favorites – using the bookmark and managing the toolbar.

Another new feature in iOS 15 Field Test Mode is Data Point Copy. If you long press on any element, it will eventually copy the measured number or text to your clipboard and you can paste it anywhere, even on your Mac if you have universal clipboard enabled.