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Best Bluetooth FM Transmitters

Learn about the best Bluetooth FM transmitters for when the radio just won’t cut it anymore.
Written and Tested By:
Ben Kasierski
Written and Tested By: Ben Kasierski Contributor – Motor1 Review Team

Ben Kasierski is a North Carolina native who covers the latest automotive and motorcycle products. He has tested hundreds of car detailing products – including tire shines,  car wash soaps, and full detailing kits – as well as gadgets to make life easier for the everyday driver like key finders and GPS trackers.

Last Updated 12/15/2023

Motor1 Reviews Team Take:

  • The best Bluetooth FM Transmitter in 2024 is the Nulaxy KM18. The KM18 from Nulaky offers Hi-Fi sound quality and noise cancellation for phone calls.
  • With an average cost of around $25, Bluetooth FM transmitters are both affordable and functional for hands-free calling and desired music or radio streaming preferences.
  • An easy installation and versatile transmitter to accommodate different smartphones and charging options are a few things we looked for when selecting the best Bluetooth FM transmitters.
Best Bluetooth FM Transmitter
Nulaxy KM18

A versatile, no-nonsense Bluetooth transmitter.

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Best Bluetooth FM Transmitter For Phone Calls
Lencent T25

A Bluetooth transmitter for high-quality calls.

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Best Bluetooth Car Charger With FM Transmitter
Imden Bluetooth C57

A fast-charging Bluetooth transmitter.

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Best Bluetooth FM Transmitter For iPhone
Anker Roav

A Bluetooth transmitter with a USB-C port.

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Best Hands Free Bluetooth FM Transmitter
Sumind BT70

A Bluetooth transmitter with a bright display.

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While most newer vehicles have built-in Bluetooth® for seamless smartphone streaming, older cars are limited to FM and AM radio. A Bluetooth FM transmitter uses short-range frequencies to send and receive information to Bluetooth devices via radio waves, acting as an alternative adapter. Not only does this let you stream your favorite music from your devices, but also provides hands-free calling and more.

Our review team has tested and rounded up our top picks for the best Bluetooth FM transmitters. We’ll discuss everything from readability to connectivity to help you make the right choice for your needs.


What Is The Best Bluetooth FM Transmitter?

We named the Nulaxy KM18, Lencent T25, Imden Bluetooth C57, Anker Roav, and Sumind BT70 as the best Bluetooth FM transmitters on the market in 2024.

Five of the best bluetooth FM transmitters as tested and reviewed by our auto product team.

Each Bluetooth FM transmitter in this review was thoroughly tested and evaluated based on several categories, including ease of installation, streaming and calls, and versatility. You can find more specifics regarding our rating system here.

The scores in each category are compiled into a single overall rating that ranges from 1.0 to 5.0 stars. Each Bluetooth FM transmitter’s ratings, including their overall ratings and awards from our team, are highlighted below:

Top-Rated Bluetooth FM Transmitters

Overall RatingAwardCost

Nulaxy KM18

5.0

Best Bluetooth FM Transmitter

$15

Lencent T25

4.8

Best Bluetooth FM Transmitter for Phone Calls

$15

Imden Bluetooth C57

4.7

Best Bluetooth Car Charger with FM Transmitter

$15

Anker Roav

4.7

Best Bluetooth FM Transmitter for iPhone

$20

Sumind BT70

4.3

Best Hands-Free Bluetooth FM Transmitter

$25

*Because cost data fluctuates, the prices in the table above are approximate values that our team regularly updates.

For those interested in learning more, we’ve provided a detailed review of each of the best Bluetooth FM transmitters in the sections below:

1. Nulaxy KM18: Best Bluetooth FM Transmitter

  • Cost: $15
  • Amazon review score: 4.4 out of 5.0 (approx. 122,000 reviews)
  • Connectivity: Bluetooth and USB
  • Power source: Battery-powered and corded electric

Nulaxy KM18 Review

The Nulaxy FM Transmitter.

Nulaxy’s car accessories are designed with the driver in mind, and the KM18 is a testament to this. Its 1.44-inch LED display is hard to miss, not to mention its flexible gooseneck allows for upward angling for even better visibility.

You can see how the Nulaxy KM18 performed in each of our testing categories below:

Review CategoryScore
(Out of 5.0 Stars)
Our Testing Highlights
Installation5.0The KM18 was installed easily into our vehicle’s auxiliary port. We were able to establish a Bluetooth connection to our phone within seconds.
Streaming and Calls5.0Once connected, the KM18 immediately streamed our phone’s music with no interruptions. We were able to make a clear hands-free call, plus the KM18 even alerted us with the caller ID on its display.
Versatility5.0Thanks to its multiple ports, the KM18 is ready for any sort of streaming users may need. The charging rate from the USB port to our iPhone was slow, though.
Overall Rating5.0An easy-to-install and incredibly versatile Bluetooth FM transmitter that’s great for phone calls and music alike.

For the hard-wired electronics enthusiasts out there, the KM18’s AUX port, USB port, and micro-SD card reader offer alternatives to wireless playback. Below are the pros and cons of the Nulaxy KM18:

Pros Noise cancellation for phone calls Strong connection Apple, Android, and Galaxy-compatible
Cons Somewhat bulbous

Nulaxy FM Transmitter KM18: Our Experience

Based on our testing, the Nulaxy KM18 is the most functional Bluetooth FM transmitter on the market. It earned the full 5.0 stars for its exceptional versatility, easy-to-read display, and superb connectivity.

Thanks to its wide-ranging Bluetooth features, the KM18 can pair with almost any Apple, Android, or Galaxy device for streaming your favorite playlists or taking phone calls.

The Nulaxy FM Transmitter installed and operating inside a vehicle.

Nulaxy KM18 FM Transmitter: What Customers Are Saying

Customers who enjoy their KM18 admire its quick phone pairing even after being unplugged and placed back in their vehicles. A frequent complaint cites poor audio quality when turned up at high volumes.

2. Lencent T25: Best Bluetooth FM Transmitter For Phone Calls

  • Cost: $15
  • Amazon review score: 4.4 out of 5.0 (approx. 46,000 reviews)
  • Connectivity: Bluetooth and USB
  • Power source: Battery-powered and corded electric

Lencent T25 Review

The Lecent FM Transmitter.

If you’re making frequent phone calls while driving, the Lencent T25 can be a very helpful tool. This Bluetooth FM transmitter uses noise suppression technology and echo cancellation for high-quality uninterrupted calling.

You can see how the Lencent T25 performed in each of our testing categories below:

Review CategoryScore
(Out of 5.0 Stars)
Our Testing Highlights
Installation5.0We had no issues installing the T25 in our testing vehicle, and the Bluetooth setup was fast.
Streaming and Calls5.0Streaming music took no hassle and the sound came through clearly. We were able to make phone calls that had no interference and didn’t echo.
Versatility4.5The dual USB ports were great for charging two devices at once. However, the T25 doesn’t have an auxiliary port, which limits the devices it can stream from a hardwire connection.
Overall Rating4.8A Bluetooth FM transmitter that works incredibly well for phone calls.

Thanks to its dual USB ports, the T25 can charge two external devices simultaneously. Its over-current protection ensures a quick charge without overloading devices, too. The T25 can also display your car battery’s voltage. Below are the pros and cons of the Lencent T25:

Pros Two USB ports Clear connection
Cons Display can be hard to read

Lencent Bluetooth FM Transmitter: Our Experience

We scored the T25 at 4.8 stars. Its hands-free calling capabilities were unmatched by the other transmitters and we thought it was very easy to install. The T25 lost some points for lacking an auxiliary port and having a small display that was difficult to read.

The Lecent FM Transmitter installed and operating inside a vehicle.

Lencent FM Transmitter: What Customers Are Saying

Positive reviewers enjoyed the simplicity of the setup process and spoke highly of its call features. One negative reviewer claimed the T25 played back static when pushed at high volumes for extended periods.

3. Imden Bluetooth C57: Best Bluetooth Car Charger With FM Transmitter

  • Cost: $15
  • Amazon review score: 4.4 out of 5.0 (approx. 28,000 reviews)
  • Connectivity: Bluetooth and USB
  • Power source: Corded electric

Imden Bluetooth C57 Review

The Imden FM Transmitter.

Because of its sleek design, the Imden Bluetooth C57 has a charging efficiency of up to 80 percent to reduce power dissipation. Its over-current and over-voltage protection prevents overcharging, which can permanently damage your phone’s battery.

You can see how the Imden Bluetooth C57 performed in each of our testing categories below:

Review CategoryScore
(Out of 5.0 Stars)
Our Testing Highlights
Installation5.0Setting up the Imden gave us no trouble and we established a Bluetooth connection with no errors.
Streaming and Calls4.5Although music came through loud and clear, phone calls were a bit scratchy. The ‘accept call’ button on the C57 was prone to sticking, too.
Versatility4.5Our phone gained nearly 10 percent of its battery back in less than 5 minutes when rigged to the C57. We noted the lack of ports for AUX cords and other USB sizes.
Overall Rating4.7This is the best Bluetooth FM transmitter we tested that connects directly to your car’s charging outlet.

The C57 is equipped with intelligent temperature control as well as short circuit protection to make sure it doesn’t fizzle out after prolonged use. And its yellow-ray LED display can act as a voltmeter to measure electrical output. Below are the pros and cons of the Imden Bluetooth C57:

Pros Great for charging devices Smooth connection Smart voice navigation
Cons Buttons can be difficult to see depending on port location

Imden C57 Wireless Bluetooth: Our Experience

Because of its sensible charging and ease of use, we gave the C57 4.7 stars. It scored well for its straightforward installation but lost points due to its limited ports and decent sound quality.

The Imden FM Transmitter installed and operating inside a vehicle.

Imden C57: What Customers Are Saying

Among positive reviews, customers praised the C57 for its dual USB design and crisp sound. There were some negative reviewers who said their Imden device stopped pairing with their phones after being turned off.

4. Anker Roav: Best Bluetooth FM Transmitter For iPhone

  • Cost: $20
  • Amazon review score: 4.1 out of 5.0 (approx. 9,500 reviews)
  • Connectivity: Bluetooth and USB
  • Power source: Car adapter

Anker Roav Smartcharge T2 Review

The Roav FM Transmitter.

While many Bluetooth FM transmitters are limited to only USB ports, the Anker Roav changes the game with its additional USB-C outlet. Due to the inclusion of USB-C ports on the latest iPhones, we named the Anker Roav the Best Bluetooth FM Transmitter For iPhone.

Considering that most smart devices are gravitating towards USB-C cords, this feature allows for greater versatility as a car charger while still providing an essential USB plug.

You can see how the Anker Roav performed in each of our testing categories below:

Review CategoryScore
(Out of 5.0 Stars)
Our Testing Highlights
Installation4.5While plugging in the Roav was simple, its automatic scanning function took a few minutes to find an open channel. Once it did, though, our phone immediately connected.
Streaming and Calls4.5The Roav streamed music and took phone calls very well. However, it lost connection at one point and had to be reconnected manually.
Versatility5.0We really liked the USB-C port, which charged our phone much faster than the regular USB. However, the Roav lacked an AUX port and also had no Micro SD card reader.
Overall Rating4.7A Bluetooth FM transmitter that can connect to the newest iPhones via USB-C.

Another worthwhile feature of the Roav is its automatic tuning, which searches and connects to open FM radio channels. The one-button call feature combined with its high-performance microphones makes phone conversations easy with little added stress. Below are the pros and cons of the Anker Roav:

Pros USB and USB-C ports
Cons Connection is not always immediate

Anker Roav T2: Our Experience

The Roav earned 4.7 stars for having a USB-C port with fast charging capabilities. It took a while for it to find a working channel, plus it disconnected without any warning. Both of these minor drawbacks were enough to deduct a small amount of points from its overall score.

We would like to note that the Anker Roav T2 only disconnected once, but this ultimately worried us about how well it would hold up in low-signal areas.

The ROAV FM Transmitter installed and operating inside a vehicle.

Anker Roav Smartcharge T2: What Customers Are Saying

One of the most consistent pros that customers point out in positive reviews is that the Roav reduces static and frequency disruptions like no other transmitter. Low call quality was a frequently cited issue.

5. Sumind BT70: Best Hands-Free Bluetooth FM Transmitter

  • Cost: $25
  • Amazon review score: 4.4 out of 5.0 (approx. 25,000 reviews)
  • Connectivity: Bluetooth, Auxiliary, and USB
  • Power source: Car adapter

Sumind BT70 Review

The Sumind FM Transmitter.

With its 1.7-inch large LCD backlight display, the Sumind BT70 is hard to miss. It can display the song name and artist when streaming, plus a contact’s name and number when they dial in for a phone call. The BT70’s gooseneck can rotate 270 degrees for a more direct line of sight when adjusted appropriately.

You can see how the Sumind BT70 performed in each of our testing categories below:

Review CategoryScore
(Out of 5.0 Stars)
Our Testing Highlights
Installation4.0The BT70 plugged in with few issues, but the gooseneck wasn’t very adjustable. It also bumped into our vehicle’s shift knob, and since the neck wouldn’t function properly we had to angle the display sideways to work.
Streaming and Calls4.0Streaming came through fine, yet calls were not perfect with the BT70. Call audio was garbled in one instance, but only for a passing moment.
Versatility5.0The BT70 offers multiple charging ports and music streaming options. We thought the dual USB design came in handy for multiple passengers.
Overall Rating4.3A hands-free Bluetooth FM transmitter that’s compatible with Siri and Google Assistant.

With its multi-port design, the BT70 can play music from USB flash drives, Micro SD cards, and Bluetooth audio. Its CVC technology creates full duplex sound while also suppressing external noise for improved call performance. Below are the pros and cons of the Sumind BT70:

Pros Dual USB ports Compatible with Siri/Google Assistant QC3.0 fast-charging port
Cons Very large

BT70 FM Transmitter: Our Experience

Due to its enhanced readability and well-designed interface, we gave the BT70 4.3 stars. We liked how many extra ports it had for music streaming of all kinds. Its gooseneck design was difficult to maneuver, though, and calls did not come through as clearly as we had hoped they would.

Our team would like to note that we established a Bluetooth connection in just a few seconds with the Sumind BT70 FM Transmitter.

The Sumind FM Transmitter installed and operating inside a vehicle.

Sumind FM Transmitter: What Customers Are Saying

A common compliment of the BT70 is its large buttons that make navigating its display very easy. Customers also like how quickly it connects to their smart devices. Unfortunately, some customers were not happy with their BT70’s build quality, saying it fell apart after extensive use.


Car Bluetooth FM Transmitter User Guide

Before deciding on your next Bluetooth FM transmitter, consider what you need from your device and how it can work best for you.

What Is A Bluetooth FM Transmitter?

A Bluetooth FM transmitter, also known as an FM radio transmitter, links mobile devices and MP3 players to a car’s stereo system using FM radio frequencies. This allows vehicles that don’t have built-in Bluetooth to wirelessly stream music and calls from a connected device. Transmitters can also charge other devices.

Some Bluetooth FM transmitters have USB charging ports, which also double as auxiliary ports. Others allow for Micro SD cards and other USB types for an even broader scope of listening options.

FM Bluetooth Car Transmitters: Compare And Contrast

Brand/ModelConnectivity TechnologyPower Source
Nulaxy KM18USB, BluetoothBattery-powered, corded electric
Lencent T25USB, BluetoothBattery-powered, corded electric
Imden Bluetooth C57USB, BluetoothCorded electric
Anker RoavUSB, BluetoothAdapter
Sumind BT70Bluetooth, Auxiliary, USBAdapter

Best FM Bluetooth Transmitter: Bottom Line

We spent hours researching and testing to find the best Bluetooth FM transmitters on the market. We evaluated each product based on installation, streaming and call connectivity, and product versatility with included ports and features for easier use.

  1. Best Bluetooth FM Transmitter: Nulaxy KM18
  2. Best Bluetooth FM Transmitter for Phone Calls: Lencent T25
  3. Best Bluetooth Car Charger with FM Transmitter: Imden Bluetooth C57
  4. Best Bluetooth FM Transmitter for iPhone: Anker Roav
  5. Best Hands-Free Bluetooth FM Transmitter: Sumind BT70

Bluetooth FM Transmitter: FAQ

Below are some common frequently asked questions about Bluetooth FM transmitters: 

How do I know which FM frequency to use for my Bluetooth FM transmitter?

You’ll want to match your transmitter’s frequency to that of the desired station on your radio for streaming. Most manufacturers provide a range of available FM frequencies that can be used for pairing. Be sure to choose a clear frequency, as ones in use will not work with a transmitter.

Will a Bluetooth FM transmitter drain my battery?

If you leave a Bluetooth FM transmitter on when your car isn’t running, then yes, it can drain your battery. Always check that your transmitter is turned off before leaving your vehicle.

Can I use a Bluetooth FM transmitter on my boat?

As long as your vehicle has an FM radio connection and an auxiliary port, it can be used to establish a Bluetooth connection. Make sure you turn your transmitter off when not in use, as some vehicles won’t automatically deactivate them.

Can I plug an AUX cable into my Bluetooth FM transmitter?

Some models may allow for AUX cable playback while others don’t, so checking your model’s features before purchasing is important.


Bluetooth FM Transmitter For Car Reviews: Our Testing Process

We used a 2014 Honda Civic SE to test our Bluetooth FM transmitters. Each one was paired with an iPhone 12 Pro. At least two songs were streamed using Spotify® to test clarity. A phone call was made to another product testing team member to test the hands-free calling features as well as the clarity of each call.

Installation

This criterion measured how easily the Bluetooth FM transmitter was installed into our vehicle’s auxiliary port, also known as a cigarette lighter adapter. Once installed, we linked each transmitter to our phone. Transmitters that were installed with little hassle and connected quickly without difficulty scored highest in this category.

When considering any transmitter, you want a product that’s going to be easy to install and automatically switch on when you start your car. A Bluetooth FM transmitter that takes little time to set up and also has a sleek design to stay out of your way while driving is ideal for functionality and safety on the road.

Streaming and Calls

This category measured the clarity of music streaming and phone calls. We factored in how easy it was to stream music from a phone, the reliability of taking calls, and how consistent the connection was during the duration of our testing process. Transmitters that worked reliably without interruption scored highest in this category.

Since your Bluetooth FM Transmitter will connect to your smartphone, you can take hands-free phone calls and stream your favorite music. With this in mind, you’ll want to find a transmitter that can work reliably and keep your calls or music connected while on the road. 

Versatility

This category measures the additional functions of each transmitter. This included the number of ports, extra features, and design. Transmitters with more features and an intuitive design for a more user-friendly experience scored highest in this category.

Some transmitters offer charging, multiple streaming options, different ports depending on your smartphone, and more to accommodate your listening preferences. While transmitters that offer more features and are more versatile for different phones might be more expensive, we think they’re worth it in the long run if you’re looking to buy a new transmitter.

How We Score Products

Star ratings help us compare products during our testing process. By looking at three important factors – installation, video and call streaming, and versatility—we scored each criterion to determine the best Bluetooth FM transmitters on the market.

Among all the transmitters we tested, we calculated an average score of 4.7 out of 5.0 stars.

  • 5.0 Stars: A 5.0-star rating means that the product scored well above average based on our testing factors. If the transmitter had a sleek design, multiple outlets or streaming options, and held a strong Bluetooth connection, you’d see a 5.0-star rating.
  • 4.0 Stars: This rating means that, while some features didn’t perform above average, they landed somewhere between an above-average and average rating. An example of this would be if the design was sleek but it lacked smartphone compatibility or different streaming options.
  • 3.0 Stars: A 3.0-star rating means that the transmitter performed averagely in comparison to the other transmitters we tested. An example of a 3.0-star rating, when compared to other transmitters, is if the item lacks connectivity reliability, affecting your driving experience.
  • 2.0 Stars: This rating means the transmitter performed below average in at least one criterion we considered when testing. If the transmitter somehow gets in the way of driving safely, loses connection, and has few options for versatility, you’ll see a below-average score.
  • 1.0 Star: While rarely featured in our reviews, a 1.0-star rating would be applicable if an essential aspect of the transmitter did not function as it should. If the transmitter never connected to our device, you would expect to see a 1.0-star rating.

Why Trust Motor1.com

Each year, we test over 350 auto products on vehicles and in our testing lab. Our team of product testers thoroughly researches top products, unboxes and puts our hands on each component, and tests the items on real vehicles before making recommendations to readers.

We publish hundreds of product and service reviews to bring car enthusiasts detailed guides on automotive tools, detailing kits, car seats, pet products, and much more. For more information on our testing methodology and how we evaluate every product, check out our methodology page here.

*Data accurate at time of publication. Products subject to availability.