ASUS Merlin Firmware [Guide] – How to flash your ASUS wireless router to Asus-Merlin firmware?


A manufacturer’s success is not on the look of the product they’ve delivered to the end user, but, the initiative taken to provide an excellent support for their products for a specific amount of time.

ASUS proved their commitment to provide the best for their end user as, all of their products, constantly receiving software support for a specific amount of time, which usually hovers in between 5 to 6 years. When it comes to networking, ASUS scores a full mark here due to their commitment to provide constant firmware update even for their older models such as RT-AC68U, “The router I am going to use today as a guide“, resulting in, the benefit of the money invested to buy their high end wireless routers. There is a good and a bad news. I will start with the bad news first, the Asus-Merlin only supports dual band AC routers starting from AC66U_B1 to the top. The good news is, even if you’re using their lower end models (single-band wireless routers) for your internet subscription below than 100Mbps, you will still receive firmware updates from ASUS and, you will be informed if your wireless router model has reached its EOL status.

Today, I am going to be focusing on the tutorial on how to flash your current ASUSWRT (Stock firmware) of your wireless router to Asus-Merlin. The process is similar on how, the normal method of upgrading / updating the firmware process. It is pretty straightforward and this guide can be used as a guide to flash your wireless router firmware to its latest patch without even needing to flash to Asus-Merlin.

Developed by Eric Sauvageau, the Asus-Merlin is an alternative firmware offering users more customization (control) over the stock firmware by ASUS. Installing Asus-Merlin won’t cause you any harm as, RMerlin linked the source code on github in order to allow the users know that, there are no shady intentions were going on via the creation of this firmware. In other word, it is really safe.

How does Asus-Merlin benefits me in any way?

I would strongly suggest you to go through the official statement of RMerlin here.

Focus of Asus – Merlin

  • Special emphasis on code tweaks
  • Bug fixes
  • Performance enhancement

Supported Models of Asus – Merlin


  • RT-AC66U_B1 [Same firmware as RT-AC68U]
  • RT-AC68U [Supports variant AC68P & AC68UF and AC1900 & AC1900P]
  • RT-AC86U [Support revision RT-AC2900]
  • RT-AC87U
  • RT-AC88U
  • RT-AC3100
  • RT-AC3200
  • RT-AC5300
  • RT-AX88U

Discontinued (EOL – End of Life)

  • RT-N116
  • RT-N66U
  • RT-AC66U
  • RT-AC56U

Pros and Cons of Asus – Merlin

Not all firmware offers perfection, as, flashing to Asus-Merlin would cost your wireless router to lose AiMesh feature, however, Merlin retains the AiProtection which a major advantage here.

Now, we’ve done the important part of what you will gain and what you will lose via flashing to Asus-Merlin firmware.

Let’s proceed with the steps, shall we?

Step 1:

First, we begin the tutorial by visiting to this site to download the firmware of your wireless router. For this, I will be using RT-AC68U as our main ‘protagonist’ for our tutorial guide today.

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I would highly recommend to use SourceForge platform to download the firmware of your wireless router.

Step 2:

Browse your wireless router model folder here. Do mind that, there are two sub-folders in the parent folder. I.e. If I select an AC68U folder (parent folder) then, I will come across with two sub-folders namely Release (Public Release) and Beta (Normally directed toward alpha and beta testers to conduct Whitebox and black-box testing before submitting the report to RMerlin to be tweaked further after approval) before the final version were released to the public under Release folder.

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For the general public, I would highly recommend to download the firmware from the Release folder. In the Release folder, browse through the latest offered firmware of your wireless router model. You can see the firmware if it is in the latest state by the provided ‘Modified’ section.


Click file name of the latest firmware. You will be directed to a download page. Wait for five seconds and your file will be downloaded.


The download speed depends on your current internet connection speed or VPN usage, such as downloading torrents and streaming.

At this point, I would suggest to stop any internet usage, i.e. torrenting or streaming or downloading process.

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Step 3:

Login to your wireless router Web Interface. I.e. There is two ways of going to firmware sub-panel of your wireless router.


  1. Click on your wireless router firmware version (the version number) located under the reboot button.
  2. Or, you can use the old school way to click the Administration panel located on the bottom left of your Web Interface and hit to Firmware Upgrade sub-panel (Step 4).

Before we move into Step 4, if you don’t have any compression tools installed in your computer, then, I would recommend giving a try to an open source compression tool, 7-Zip.

Step 4:

Now, this is the most important part. You might come across with few buttons like two Check buttons. But, where do I can actually manually upload the downloaded Merlin firmware? Do not worry. Click on the Upload link and a windows popup will pop up.


Extract the firmware using the compression tool I’ve suggested or your own preferred compression tool.


Select the Merlin firmware with .trx extension and click on Open button.

Step 5:

Your firmware should be automatically begins the upgrading process. Do note that, the process usually consumes three minutes to complete. At this moment, you will lose the internet connection.

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Once the process finishes, you can login to your wireless router Web Interface, and the UI is almost identical with the stock firmware, but a with few tweaks such as the Tools panel and the wizard icon located next to your wireless router model and loses an AiMesh button (AiMesh not supported in Asus-Merlin).

Asus-Merlin web interface of RT-AC68U.

If you wish to revert back to the stock firmware, just follow the above steps only by uploading the original ASUSWRT firmware and, and in some cases, factory reset the wireless router to its factory settings and set the wireless router again is needed. This tutorial also can be used for users who wish to manually upload the latest firmware from the ASUS website.

Congratulations, you’ve successfully flash your ASUS wireless router to Asus-Merlin and unlocked the router from Saiyan to Super Saiyan mode.


Basically, the stock firmware provided by ASUS is better than most wireless router manufacturers out there, but, Asus-Merlin is one step above the ASUSWRT firmware. If you’re a normal home user who only use the internet for daily task, then ASUSWRT (stock firmware) is recommended for you, however, for the users who likes to tweak their wireless ASUS router for even peak performance, then Asus-Merlin is the answer to your cravings.

2 comments on “ASUS Merlin Firmware [Guide] – How to flash your ASUS wireless router to Asus-Merlin firmware?”

    1. Good day mate,

      Pardon me for the delay in replying you. For your queries regarding flashing AC68U merlin to a 4G-AC68U, the answer is, it won’t work. It is not recommended as well. The hardwares of the both units are different. For your further clarification, kindly refer to these forums and particularly reply from the developer of Asus-Merlin himself. Link:

      Have a great day ahead.

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