Rabby browser wallet: what it does and how it works

Rabby is a browser wallet for Ethereum and networks that work like it. Its main idea is safety while using crypto apps: before you sign anything, it simulates the transaction and shows what will leave and enter your wallet.

Who makes it

Rabby is published by Opcode Labs, a company in Singapore. It is closely linked to DeBank, a well-known crypto portfolio tracker, which runs its bug bounty.

What you can do with it

See what a transaction will do. Before you sign, Rabby runs the transaction in a simulation and shows the expected balance changes. It flags suspicious approvals, risky contracts and swaps with a bad price. You can still sign past the warnings, so read them. Lesson 37 explains why approvals are the most common way people are drained.

Use Ethereum-style networks. Rabby supports Ethereum, BNB Smart Chain, Avalanche, Arbitrum, Base, Optimism, Polygon and many others, and you can add custom networks with fewer features. It does not support Bitcoin, Solana or Tron.

Switch networks automatically. When an app asks for a different network, Rabby changes to it for you instead of making you switch by hand.

Swap and bridge. Built-in swaps and bridges charge 0.25%, included in the quote. Some same-network swaps between closely related tokens are free.

Pay gas without the right token. GasAccount is a prepaid balance that pays network fees on supported networks. You fund it with tokens, or on mobile with Apple Pay or Google Pay. Money added by card cannot be withdrawn.

Use many hardware wallets. Rabby supports more devices than most: Ledger, Trezor, BitBox02, Keystone, OneKey, GridPlus, NGRAVE and others.

What it is less good at

It covers only Ethereum-style networks, so Bitcoin or Solana holders need a second wallet. It does not run in Firefox. Its simulation is a strong safety net but not a guarantee: it estimates, and a determined scam can still fool it.

Is it safe?

Rabby is self-custody. Its extension code is published under an MIT licence, which lets outsiders check it. Security firms audited it in 2025: one gave a passing result, another listed issues still open at the time.

In October 2022, a flaw in Rabby's swap contract was exploited for about $200,000, and users were told to revoke their approvals to it. Lesson 37 shows how to check and revoke approvals.

Fake "Rabby" extensions exist in browser stores. Install it only through rabby.io.

Who it suits

People who use DeFi apps on several Ethereum-style networks and want to see what they are signing. Beginners who only hold Bitcoin or Solana need a different wallet.

Setting it up safely

1. Install from the source. Go to rabby.io yourself, by typing the address, and follow its link to your browser's extension store. Do not use search ads or links from messages. On the store page, check the publisher name and the number of users.
2. Write the seed phrase on paper. Rabby shows it once when you create a wallet. Write every word in order and keep it offline. Lesson 30 shows how, and our free backup card helps.
3. Never type the phrase anywhere else. No genuine site, support agent or app update will ask for it.
4. Start small. Send a small amount first and check it arrives before moving more.
5. Review connections. From time to time, remove app connections and token approvals you no longer use.

How it compares

Compared with MetaMask, Rabby charges less on swaps (0.25% against 0.875%) and supports more hardware wallets, but covers only Ethereum-style networks. If you also hold Solana or Bitcoin, you will need a second wallet such as Phantom. The MetaMask guide covers the most common alternative.