Active RFID vs. Passive RFID: What’s the Difference?

Active RFID vs. Passive RFID: What’s the Difference?

Short Answer:

Active RFID systems use self-powered RFID tags that continuously broadcast their own signal. Active RFID tags are commonly used as “beacons” to accurately track the real-time location of assets or in high speed environments such as tolling. Active tags provide a much longer read range than passive tags, but they are also much more expensive.

Passive RFID systems use tags that are powered by the electromagnetic energy transmitted from an RFID reader. Passive RFID tags have applications including access control, file tracking, race timing, supply chain management, smart labels, and more. The lower price point per tag make employing passive RFID systems economical for many industries.

Long Answer:

Active RFID

Active RFID Tag

Example of an active RFID tag

Active RFID tags possess their own power source and transmitter enabling the tag to broadcast its signal. Performance capabilities include longer read ranges and greater memory capacities when compared to passive RFID tags; however, in order to achieve a significant read range and larger memory, these performance capabilities generate a greater demand for power. Typically, active RFID tags are powered by a long life battery that will last a few years, but will eventually require replacing.

Essentially, two different types of active RFID tags are available on today’s market – Transponders and Beacons. An active RFID transponder only communicates when in the immediate presence of a reader’s interrogating signal, thus conserving battery life when the tag is out of range of the reader. Active RFID transponders are commonly used in secure access control and in toll booth payment systems.

Active RFID tags purposed as beacons will periodically transmit their identifying information at user defined intervals and RFID reader antennas will read and determine the tag’s location with the help of back-end software. This type of active RFID tag is frequently used in real-time location systems (RTLS) commonly found in outdoor shipping yards and throughout supply chains. Some active RFID tags have a read range capable of reaching 100 meters in ideal outdoor environments.

Active RFID tag with hardcase

A hardshell active RFID tag

Tasked with weathering harsh environmental conditions such as extreme temperatures and moisture, some active RFID tags may be encased in a rugged shell. Because of the size of the enclosed battery, circuitry, and bulk of a durable exterior, active RFID tags are usually much larger than passive tags. Also, some active tags may have on-board sensors that track environmental parameters.

All these additional features translate to increased costs for the customer, but the return on investment of a system may far outweigh the initial costs. The prices of active RFID tags range anywhere from $20+ to $100+ depending on the tag’s ability to withstand harsh conditions and other key functional features of the tag. Given the required investment of an active RFID system, active tags are usually reserved for tracking high worth assets or for items where accurate location tracking is necessary to the success of the system.

Passive RFID

Unlike active tags, passive RFID tags have no internal power source. A passive RFID transponder consists only of a microchip and an antenna; the two together are commonly referred to as an RFID inlay. As the name implies, passive tags wait for an interrogating signal from an RFID reader. Once the tag is within range of the interrogation zone, the RFID tag’s antenna draws energy from the electromagnetic waves.

Once the tag’s microchip, or integrated circuit, becomes powered, it transmits a signal. The change in the electromagnetic wave is detected by the reader’s antenna which interprets the information. For the process to work properly, the antennas in both the tag and reader must be at least within several meters of each other; however, the read range depends on the transmit frequency, equipment settings, and other environmental factors.

Passive RFID tag

A roll of Passive RFID inlays

Passive RFID tags generally operate at three distinct frequencies:

  • Low Frequency (LF) 125 -134 kHz
  • High Frequency (HF) 13.56 MHz
  • Ultra High Frequency (UHF) 856 MHz to 960 MHz

As frequency increases, the radio wave’s ability to penetrate liquids and metals decreases, and, generally, read range increases as frequency increases. Technology has improved in recent years, and specialized UHF RFID tags can operate around water and on-metal surfaces with minimal interference. Some applications, such as NFC payment systems, have adopted short read ranges as a unique feature. Near field communication (NFC) is a specialized subset of HF RFID and considers short read range a benefit and is a hallmark capability of the NFC protocol.

Passive and Active RFID Tag

Size comparison between passive and active RFID tags

Since passive RFID tags do not have their own power source, they typically have lower memory capacities and significantly shorter read ranges than their active counterparts; however, passive tags are drastically cheaper with prices ranging from pennies up to several dollars. Passive RFID tags are much smaller than active tags, and depending upon the application, passive tags may be as thin as a few sheets of paper.

As the cost of passive RFID tags continues to decrease, a greater number of industries are adopting the technology, and many companies are replacing standard barcodes with RFID labels. Passive tags are found in asset tracking, tool tracking, event monitoring, access control, race timing, and variety of other applications.

While both active and passive RFID technologies use radio frequencies to communicate information, each is very different, and likewise, possess different qualities well suited for varying applications.

If you have any questions about active and passive RFID, leave a comment below of email us at

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About James Thrasher

James is a contributor to RFIDinsider and the Digital Marketing Manager for atlasRFIDstore. When he's not following the latest news in tech, James is probably watching a basketball game. He currently resides in Birmingham, AL with his wife.

  • Yasir

    Which will be source of current in passive r.f.i.d ,if we will inject it in any human body for a longer time…?

    • atlasRFIDstore


      Thank you for your question. Due to the amount of water in the human/animal bodies, tags that work on Low Frequencies (with longer wavelengths) are required. These LF tags are typically in the 125 kHz to 135 kHz range and are usually passive tags in that they only respond when interrogated by an RFID reader on the same frequency.

      These passive tags work essentially by harnessing enough energy from the reader in order to excite the tag and enable it to respond. In the case of passive LF tags, the read range is very short (i.e. a few centimeters).

      See our blog post for more details:

  • Sonya Fnkey

    Interesting. The very first question concerns an RFID implant into a human body. And just suppose, for a moment, that the power is jacked up and size is dialed down enough to be injected by hypodermic needle. And just suppose, for a moment, that everyone will be required to have this kind of implant in their hand or forehead, if they want to buy or sell… Do you read me?

    • monarch

      so scary!!

  • Muhammsman

    how to find Acrive Tag Location….?

    • atlasRFIDstore

      Determining an active RFID tag’s location is possible but requires creating some complex software algorithms.

      For example, if you are using an active RFID setup indoors, you could place readers in strategic locations and gather data every time the active tag beacons. With that data and the known locations of the fixed readers, the software program could “triangulate” the tag to give an approximate location. The more readers that are involved and the more tag reads received, the more accurate the assumed location would be.

      This could also be done in a similar fashion outdoors by including data from a third technology (GPS). Currently, this is being utilized to track materials in outdoor laydown yards (

      Of course, as with any RFID setup, you’d want to thoroughly test, adjust, and test again to ensure you will achieve the desired results.

  • silent soul88

    I am currently working on my Capstone project about attendance monitoring system using rfid… can you please help me….

  • James

    What are the largest advantages of using RFID’s to track tools, calibration information, or other Preventative maintenance requirements?

  • Shafawati Abd Malek

    Hi, how can I choose the best rfid passive tag for monitoring c-parts at pallets or bins?

  • rodolfo tuble

    Good day,

    We’re looking for a passive rfid that has a large user memory. That can hold a user profile as information, this would be around 1 to 10 thousand ascii characters.

    Is this possible with the current rfid technology? Since what we’re planning is to create a system that can store valuable health information about the user, this will include your basic information, allergies, and major medical information that might prove usefull in emergencies.

    Thank you

    • James Thrasher

      Well, active RFID tags have a much larger data capacity, but past one thousand characters will push the upper limits of data capacity.

      If you wanted to use passive RFID, I would suggest encoding the tag with a unique user id that is tied to a secure database which stores the patient information. However, I don’t believe this would be practical in an emergency outside of a hospital setting as no one will likely have an RFID reader.

      • rodolfo tuble

        We will be the one to provide the readers, we also thought of just storing a unique id in the tag but the information will be stored online thus in the event of no internet connectivity the information cannot be retrieved, so we were hoping to find an rfid that can hold that much information, is it possible?

    • Ben Portman

      I work for Fujitsu and we manufacture a high memory passive tag. 8k and 64k. Ther tag can be partition like a disk drive. contact us at 425-466-9651

  • E_Grise

    So, I’ve got an RFID reader that will read my passive RFID tags and control a lock on my back door. But that requires me to take the tag out of my pocket and hold it up close to the reader.

    I’d like to be able to use active RFID tags so that the tag can just stay in my pocket. Are there active RFID tags I can use instead of/in addition to my existing passive ones?

    • James Thrasher

      Your current RFID tag and reader is probably NFC, which has a short read range of a few centimeters.

      If you’re looking for a read range of several meters, you want to start with UHF RFID first before moving to active RFID, which has a read range of up to 100 meters. That long of a read range isn’t ideal for security reasons, and the cost of installing the system is considerable.

      For your use case, I’d recommend researching home automation hubs, like Smarthings ( or something similar. When the hub detects your phone (or a Bluetooth sensor), you can set up logic that will unlock the door, provided you have a compatible door lock.

  • Erdem Şimşek

    Hi ,
    I will use active rfid tag and active rfid reader .But readers are so expensive for my personal workshop . I am curious on are there any chance to use passive rfid reader instead of active rfid reader .

    Or , do you have any suggestion for my system , It is based on sending sensor data and localisation .

    • James Thrasher

      I can’t really recommend anything since I don’t have any information about your system, but if you’re just tracking items in a workshop, then I would definitely look at passive systems first.

      Passive UHF tags will have a read range of several meters, but it all depends on the size of the tag, the environment, and several other factors.

      Here’s an article that discusses ways to improve read range:

      • Erdem Şimşek

        I will try to make wristband that includes sensor . The wristband sends data to reader by using rfid system . With my software , i can track the wristband position and sensor values instantenoulsy by using rfid technology

        For now , i am using infrared led trasmitter and receiver . But , it is not a solution because , The wristband have many problem such as being same direction with the receiver and more

        Maybe , bluetooth will be cheaper than RFID

        • James Thrasher

          Bluetooth will be a solid option, but I wouldn’t rule out passive RFID. The RFID tags themselves will be cheaper, but using sensors does complicate the issue.

          Since you’re developing a very specialized system, you might want to look at Thingmagic’s RFID Reader Module development kits.

  • Shannon Gowan

    I was wondering if the RFID wristbands are able to use both a NFC and UHF chips in the same band, or if it will create incompatible signals? The thought is for large scale events such as concerts or festivals to use the NFC chip for admission/payment, and the UHF chip for photography. Any help would be greatly appreciated! Thanks- shannon

    • James Thrasher

      Yes, you can have both an NFC and UHF RFID chip on the same wristband. It’s not a standard product, but can custom make the dual-frequency wristbands for you.

      The one caveat is that the human body will sometimes limit the read range of UHF tags, so testing will be important.

      A sales engineer can provide more in-depth answers here:

  • Chandara

    I am using passive RFID tag with Fix RFID reader. I think RFID is not good to use once the tag item in box that have items up to 300. The reader cannot receive all the tags in the box.
    Can you help to solve this issue for RFID reader to read hundred item in the same time with accuracy?

    Thank you.

    • James Thrasher

      It’s not an issue for most readers to read hundreds of tags at the same time.

      However, in your case, since all of the items are being stacked on top of each other inside of a box, the radio frequencies are effectively being trapped and blocked. Also, if there is a lot of metal present in either the items or the box, the effectiveness of the passive RFID system will be reduced further.

      You can experiment with different tags designed for metal environments:

      Also, you could review your processes. For example, would it be possible to read the tags as they are placed into or removed from the box? Could you use different boxes?

      Hope this points you in the right direction.

      • Chandara

        Hi James,

        Yes, all the item are being staked on the top of each other inside of a box but there is no present of metal in the box.

        I have tested with items out of the box to see the effectiveness of the reader and the tags. It still not help the issue, even I keep very close to the items to the four antennas. It is still not work. the result from the reader is only around 100 counts. I use Motorola FX9500 with 4 Antennas.

        It is strange to me.
        Could you please share you the same experiences on this matter or
        any equipment could help or maybe I need to increase up to 8 antennas?

        Thanks you.

        • James Thrasher


          The Zebra FX9500 should be able to handle a high volume of reads. You may want to consider testing different antennas or tags. I would suggest testing different tags first since that’s generally the cheaper option.

          Also, You probably know this already, but thick plastic materials and the presence of liquids will affect performance as well. You would want to test on-metal RFID tags if that is the case.

          If you would like to test the strength and coverage of the RF field, you may want to use something like this RF Power Mapper:

          Hope this helps.

  • Alpesh Dnk

    if i can choose UHF rfid device 15 meter range..and 5 people 15 under range with UHF card and some people card on hand,some people card on wallet,pocket,bag and in this scenario can read UHF reader this people UHF card tag data..
    please suggest this scenario i can preferred UHF devices or ACTIVE card reader devices

  • Cristian canales


    I need to read a box with about 400 tag inside of it.
    I want to use UHF pasive chips, and active readers.

    The idea is that a box with the tag passing throw the VC-420T gate and this will be capable to read de id of the chip without colision.
    Is that possible?

    • James Thrasher

      In order to read UHF passive chips/tags, you need a UHF reader. An active RFID reader will not be able to read those chips/tags.

      Also, if the reader does not have an integrated antenna, you will need to purchase an antenna separately.

      Are you trying to read all the tags inside the box, or just the box as it passes through the gate?

      • Cristian canales

        im trying to read all the tags inside the box while this is passes through the gate.
        the dont really need to be 400, it just a case, but with 200 will be enough

        • James Thrasher

          If you decide to use passive UHF tags and readers, you’ll need to choose the right type of tags depending on the material of the box.

          You’ll want to test first, because depending on what you’re tagging and the material of the box, the performance could be impacted.

          Here’s an article discussing on-metal RFID tags:

  • Prajnamaya Dass

    Can the passive tag generate the current time and date after getting the RF signal from the reader ?

    • James Thrasher

      It would happen in reverse. Whenever the RFID reader interrogates the RFID tag, the reader could note the time of the read.

      • Prajnamaya Dass

        thanx for the reply.
        According to you an rfid passive tag doesn’t have a clock generator inside it.
        It will send the time if and clocking device connected to it or the reader will have to note the time it get response from the tag.
        Am I correct ??

        • James Thrasher

          Yes, the passive RFID tag doesn’t perform any functions on its chip. Generally, the tag just stores information.

          The reader will have to note the time.

          • Prajnamaya Dass

            Thank you.

          • Prajnamaya Dass

            in rfid security authentication protocols, it is mentioned that rfid tags can perform hash operation , random number generation in them. These are possible.So I am just confused whether it is possible to generate current time and date in the tag or not.

  • gabby ajibola

    Hello I have a RFID implant inside me as somebody has injected it into and I wasn’t aware, I think it’s a RFID microchip for animals and somehow it works on humans or it might just be a RFID implant for humans. I don’t know where it located but I would like to know how to destroy the frequency or the device. I can hear the people who are doing this and they can see and hear what I’m thinking, it sounds absurd but this is the case. How would you suggest going about this?

  • Peter

    Hi James, do you know if active or semi-passive RFID technology is currently in use with any of the airline baggage tracking or is approved for (flight) luggage bag trackers? Thanks! Pete

    • James Thrasher

      We actually have an article on an airport who uses RFID to track luggage:

      I don’t believe it’s a common use however.

      I don’t know for sure, but I would wager that the airports who are tracking luggage do so with passive RFID tags.

  • Rajesh Bhuwalka

    Hi, I want to use UHF chips for school students entering & leaving the school to record their attendance. Read Range should be at least 10 mts and students will be entering or leaving in groups…not necessarily in a straight line so we may not have line of vision at all times. Please suggest which UHF chip & Reader should be used for best results.