FTDI chip real of fake ? How to spot a fake RT232R / RT232RL and others ?

Here is a 5 minute test:

1) purchase your boards in pairs this helps detect same serial number in case of fakes. Any board you buy under $5 is probably a fake, since the bare chip costs ~$4.

2) get your chip serial number, this can be done either by downloading the FT_PROG software or even easier from Device Manager > Ports > USB Serial Port (COMx) > (Right Click) >  Properties > Details > Device Instance Path , the Serial Number is in the value after the “+” sign following the PID . For example in screenshot below it is A704DEPPA.

3) google your serial number, those faking the chip are on a tight budget so they have no time to change it, although it is quite possible that some will change it

4) if you find your serial number for example A50285BI is a popular fake, chances are you got a fake

5) Most important: do a favor to the next person and post your serial number in the comments below, in case it is a fake it will appear in Google results for next person getting a fake with same serial #.

Why it is important to spot a fake FTDI fake  and why I am posting it ? Because it can ruin your day like it did for me ! Fake FTDI chips are unreliable especially at higher baud rates and you may be pulling your hair troubleshooting your project while the problem is in fact a cheap fake chip.

Hope this helps someone,

How do you test your chips ? Comments are welcome below .




11-7-2015 12-22-37 PM

11-7-2015 12-23-11 PM

27 thoughts on “FTDI chip real of fake ? How to spot a fake RT232R / RT232RL and others ?

  1. Fake-FTDI Reply

    Another fake (barely functions with a lot of errors): FTB6SPL3


    • Ben Reply

      I know as crazy as it sounds when ftdi decided to brick all the clones they actually sent patches to the linux kernel! But my point here is those patches should have the code/logic to determine authenticity. Anybody have a link to those patches?

  2. Peter Reply

    Got a fake,
    here’s the ID: FTDIBUS\VID_0403+PID_6001+9&37553076&0&2\0000

    Serial number is 37553076, right?

    Works surprisingly well with 1MBd, but DTR, RTS pins have insufficient drive capability.

  3. John Reply

    Another one: FTDIBUS\VID_0403+PID_6010+6&32A5DFEC&3&1&1\0000. Problems detecting on first connect.

  4. L Reply

    bought a couple of them one was fake, the other A400DE3U most probably fake too

  5. jon Reply



    Works OK, but I’m not even pushing it.

  6. Conundrum Reply

    Same here. Alas this one not only is fake but botched some very complicated code.

    Note: symptoms are really strange, if you program some PICs it overwrites specific bits requiring you to put a generic jump instruction at location 0 for the code to run correctly.
    Wish I’d known before as it really does suck.

  7. jhmrsk Reply

    Got a batch of 10 from China, all with serial A5XK3RJT.
    Chips are not labeled on the top, but on the bottom “59j17”. PCB labled with “HW-417-V1.2”.
    AliExpress refunded cause these are fakes obviously.

  8. Chris Swan Reply

    A5XK3RJTA on an adaptor I got from eBay in the UK, also found in a review for an adaptor on Amazon in Germany

  9. Bertrand Reply

    The serial number of my fake FT232RL is 00000000.It seeems to work well, even at speed higher than 115200 bauds.I didn’t try to use the bit-bang mode, so I don’t know if it is a good clone or not.

  10. mcmedd Reply

    Fake chip 00000000, bought via Aliexpress company name: Shenzhen EB-LINK Technologies. Please don’t buy from this seller.

  11. Mikael L. Reply

    I just bought 20 modules ( https://i.imgur.com/rssuYYl.jpg ) and I found this article when I realized that all of the working ones had the same serial number and searched for it online, it was the very same mentioned by the author. Thanks for sharing!

  12. gl Reply

    Another thing to watch out for is that the EEPROM can’t be programmed with FT Prog with at least some fakes. It will pretend to succeed, but when you replug it any changes made didn’t stick.

    In the past FTDI briefly disabled fake chips by writing invalid hardware IDs into their EEPROMs. It seems likely that the fakers disabled their EEPROM writes as a countermeasure. This is quite a long time ago, but I only recently had one like that again off Ebay, so those chips are still out there. Strangely, of the two boards I bought from the same seller, only one had the disabled EEPROM and known fake serial no, the other was fine, so maybe even the manufacturer got duped (or careless).

    • gl Reply

      .., just ordered 5 from Amazon, and all 5 were fakes with unprogrammable EEPROMs. There were red ones that break out all the pins (not just the usual 6) and voltages. Shame, great board!

  13. PSL Reply

    I have FAKE RT232RL with serial number A50285BI. I cannot use it with “stcgal” programmer under Linux to program STC51 MCU, it doesn’t work. Genuine RT232RL works great in the same configuration. It is interesting that I can program the same STC51 chip with FAKE RT232RL under Win7, it works there without any issue…
    STC51 chips are easy to program, they just need an USB to serial adapter. FAKE chips has some compatibility problem and it doesn’t work under Linux… :-(

  14. Christian Reply

    A variation of one of the fakes: A50285BIA


  15. ed Reply

    FTDIBUS\COMPORT&VID_0403&PID_6001 is FAKE too, based on the pictures in this article: “https://zeptobars.com/en/read/FTDI-FT232RL-real-vs-fake-supereal” and in some speed test made in the lab.
    Is coming in a Waveshare product: UST to RS232/485/TTL

    I’ve found and alternative chip of Texas Instruments “tusb3410” in the product UPort 1150l of MOXA.

  16. wookiecookie Reply

    Got a fake off AliExpress with S/N A50285BIA

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