Harmony Launches Binance Smart Chain Bridge

A guided look at Harmony’s Ethereum and Binance Smart Chain bridges

A guided look at Harmony’s Ethereum and Binance Smart Chain bridges

Photo by darylgio agoncillo on Unsplash

Harmony protocol announced yesterday that they’d expanded their bridge to support Binance Smart Chain (BSC) in addition to Ethereum, which was already supported.

This is great news for two reasons. First and most obviously, it provides another on & off ramps to BSC, which has a vast ecosystem of dApps. Second, it provides me, a user in the United States, with a bridge from Ethereum to BSC.

You see, the Binance Bridge isn’t available to US users. There’s no great way for me to get funds onto BSC other than by going through Binance US.

Source: binance.org/en/bridge

I’ll explore both the existing Ethereum bridge and the new Binance Smart Chain bridge in this story.

The Ethereum bridge

A bonus third-and-more-personal reason to be excited is that it won’t cost me $20 to try it out #TheFeesAreTooDamnHigh. I haven’t played with Harmony’s Ethereum bridge because I don’t have any “real business,” and it’s simply too expensive to use just for tryin’ it out.

To that end, I won’t complete a transaction, but let’s at least take a look at the experience.

To use the Ethereum bridge, browse to https://bridge.harmony.one and select ETH > ONE. Connect your Ethereum wallet via MetaMask, and you’re ready to go.

Let’s say I want to move 500 REEF tokens from my Ethereum wallet onto the Harmony chain. REEF isn’t one of the pre-configured tokens, so we select ERC20 and enter a custom address. When the Change token button is pressed, the token is recognized, and the prompts & available quantity will be changed & populated accordingly.

Source: bridge.harmony.one

Specify the amount to transfer and ONE wallet address, then click Continue. Since I’m using the same wallet on Harmony, I can conveniently use the Use my address link button to populate my address.

Next, you’ll be prompted to approve the amount. I won’t lie — I don’t quite understand this step. It tells me that the minimum is my transaction amount, but I can specify a larger amount to save on approval later. Perhaps to cover additional gas fees? (If you know, please help me understand by leaving a comment!)

Source: bridge.harmony.one

Click Continue again, and we get to my favorite part — the final confirmation, where we learn that it will cost $23 to transfer $20 of REEF!

Source: bridge.harmony.one

That obviously doesn’t make sense, so we’ll cancel the transaction and leave our 500 REEF for another day.

The Binance Smart Chain bridge

Those fees, right? Binance Smart Chain is much better than Ethereum in this regard, so let’s attempt the same operation using Harmony’s BSC bridge. The steps are the same, except this time, we’ll click the Binance toggle and connect a BSC wallet with MetaMask.

Source: bridge.harmony.one

Once again, I’ll enter the REEF contract’s custom address, and the page will update with the prompts and correct balance.

Source: bridge.harmony.one

Click Continue through to the confirmation, and this time we see that the transaction fee is just $3.23 — much better!

Source: bridge.harmony.one

While it’s still not ideal to pay $3 to move $20 of assets, it’s infinitely times better than paying $23 to move $20 of assets! So, this time we’ll go ahead and proceed. You know, for science.

When you click Confirm, the view expands to show a step-by-step view of the actions that must be executed. The experience is actually quite nice, and the full operation takes about 2 minutes to complete.

Once it’s done, you can easily see the new tokens in your ONE wallet by connecting the wallet to the bridge UI.

Source: bridge.harmony.one

If I wanted to move the tokens back to BSC from Harmony, I repeat the steps of specifying the custom token address and clicking through to the confirmation — but we see the return trip will cost less than $1.

Source: bridge.harmony.one


Harmony continues to impress me with its speed and low fees every time I touch it. The bridge experience is a huge step toward making cross-chain everything we might want it to be — a place where you can move tokens quickly and cheaply between blockchains. It feels less like the experience we’ve come to expect from Ethereum and more like the real-time native web app we’re accustomed to.

If you haven’t tried Harmony, give it a shot. It only costs you a couple of dollars. Once you experience how fast it is, you won’t want to go back.

Ethereum, BSC, and others aren’t going anywhere, and we’ll surely see different apps on different chains that emerge as clear leaders for their various purposes. Bridges like what Harmony has created are essential for the cross-chain ecosystem to thrive, and they show us that it doesn’t need to be hard, slow, or expensive.

Harmony is making me redefine my expectations for blockchains. The Ethereum and BSC bridges are an important step, and they work great. I can’t wait to see what comes next from Harmony!

This story was originally published on This Crypto Life on March 24, 2021.

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