Uniden R4 vs R8

Two of the top radar detectors from Uniden are the R4 and the R8. These two products look similar and have some of the same technology, but they are at opposite ends of the price spectrum. We are going to look at the Uniden R4 vs R8 detectors and show you the differences and why we think that you’ll like the R8 over the R4 (>>> Find how much it cost on Uniden.com).

Uniden R4 vs R8 Side by Side:

Uniden R4Uniden R8
RangeExtreme LongExtreme Long
Built-in GPSYesYes
DisplayFull-color OLEDFull-color OLED
False Alert FilteringYesYes
Red Light & Speed Camera AlertsYesYes
Speed-based Auto MuteYesYes
Bluetooth connectivityYesYes
Price Find on Uniden.com

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Uniden R4 vs R8: Common Features

Both of these detectors have a similar, angular design and mount to the windshield of your vehicle. They feature large screens that provide information about the incoming signal. On paper, both of these detectors include many similar features, including dual low-noise amplifiers that ensure long-range detection, GPS, auto lockouts, and several other user-friendly features.

Both designs have the majority of their command buttons located on the top of the device. This is where you’ll access power, volume, and menu options. The front of the designs includes mute and mark buttons.

GPS and Auto-Lockouts

Both the R4 and R8 have built-in GPS that allows the detector to automatically eliminate false signals that generate from the same location on your route. This includes sources like automatic doors that you don’t need to know about.

In practice, both models have some practicality issues in regard to the lockouts. Most of the time, they will either not automatically set or will trigger unless you are very close to the source.

GPS also allows the R4 and R8 to have a preloaded database of red light cameras and speed traps so you’ll get alerts about the presence of these threats before you are caught.

Dual LNA Function

Low-noise amplifiers are used by radar detectors to amplify signals to ensure the unit can accurately interpret the signal, even when it is faint. While many devices use an LNA, both the R4 and R8 use dual LNAs to ensure that even low-amplitude signals are accurately captured.

On paper, both the R4 and R8 have identical LNA technology, but in actual use, the combination of an advanced processor and higher-quality LNAs in the R8 result in noticeable long-range radar detection abilities, particularly on K and Ka-band frequencies, the most likely to be in use by law enforcement.

Advanced False Alert Filtering

The R4 and R8 provide industry-leading false alert filtering that actually works. While neither device is 100-percent perfect, both of these devices are among the quietest you’ll ever use. Both devices offer Bluetooth capabilities to update the internal database for recognizing driver assist features. Each car manufacturer uses a specific frequency that the detector must have a database record of in order to screen it out. Users report that Mazda CX-5 vehicles are the most common to trigger a false alert.

Generally, you’ll notice these detectors do a fantastic job with signals like automatic doors and other vehicles. There is no noticeable difference in the level of false alert filtering you’ll notice.

Practical Differences

The R8 does have some practical abilities that set it apart from the R4. During independent testing, the R8 consistently tested better than the R4 when using several of the K-band and Ka-band while equaling or beating it in every other category despite similar features and functions.

The digital signal processor in the R8 also provides for a faster response time, giving you more warning when a threat is encountered. The dual LNAs work better than the R4 that lets the device provide ample warning.

Directional Arrows and Dual-Direction Antenna

The R8 display provides you with arrows that indicate the direction of a threat. This is an excellent and useful technology because it helps to know if you are approaching a threat or are being followed by one. It is also helpful to see which side the threat is on, as this helps you be more aware.

The R8 uses two antennas that allow it to capture 360-degree threats. While the R4 may capture signals from other places than in front of you, it won’t tell you where the threat is located. This basic tech is way more useful than you’d think and even helps to identify false alerts when they happen because you’ll see the arrows point at a car or a business.

Why We Pick the R8 Over the R4

The R8 is a more accurate, longer range, and faster radar detector than the R4. While both devices offer some of the best practical features and functions on the market, we think the R8 is a great choice. Probably the biggest issue is the significant difference in cost to purchase. If you are trying to determine the best budget option, the R4 is going to suit most of your needs. If you want the very best radar detector available, the R8 should be one of your top looks.

Product Reviews

We will give you  a breakdown of these two devices so that you can quickly compare the features and functions.

Uniden R8

Uniden R8

The Uniden R8 is the flagship radar detector that Uniden offers. The detector has sharp, angular features and a large, vibrant OLED display screen. Large function buttons on the top provide easy access to key features, while mute and mark buttons are conveniently located on the front below the display.

The detector mounts with a large, stable suction cup that attaches to the windshield. Uniden’s cup-mount system has been proven to work well even on heavily sloped windshields and in excessive temperatures.

The detector has dual LNAs and dual direction antennas to capture all of the common radar signals. It will also notify you when your vehicle is under laser attack. Directional arrows indicate the source of radar signals, while advanced false alert filtering reduces annoying false signals.


  • One of the best long-range detectors available
  • Exceptional false alert filtering makes this a quiet and reliable detector


  • Auto lockouts don’t always work well
  • Currently no app to update the detector

Uniden R4

Uniden R4

The Uniden R4 is an advanced version of the legendary R3. It combines high-accuracy with exceptional range and advanced filtering to prevent false alerts. The detector uses an improved design that retains the angular design of the R3 but offers a sleeker and more modern look. It has large function buttons on top and mute and mark buttons below the display. Click here for our more in-depth review of the Uniden R4.

When it comes to mid-range detectors, the R4 beats out most of the competition in terms of detection range and accuracy. The OLED display indicates the type of threat and the amplitude of the signal.


  • Accurate radar detection with long range
  • Better than most other options and nearly as good as the best


  • No directional arrows to indicate direction of the signal


The R8 is a higher-range option but has several features that set it apart and make it more desirable for most people who are interested in having the best radar detector possible (>>> Check on Amazon).

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uniden-r4-vs-r8Two of the top radar detectors from Uniden are the R4 and the R8. These two products look similar and have some of the same technology, but they are at opposite ends of the price spectrum. We are going to look at the Uniden...