From Fantom to Sonic: The Complete Guide to Swapping FTM for S

The blockchain industry moves quickly. What looked advanced in 2020 can now struggle with today’s demand for low fees and high throughput. Fantom (FTM), once marketed as a high-speed “Ethereum killer”, has moved into its next phase: Sonic (S).

This is not just a new name or ticker. Sonic is a significant redesign of the network’s core infrastructure, focused on fixing “state bloat”, a long‑running problem for many older blockchains. For FTM holders, this upgrade comes with a token migration. Whether your coins are on an exchange or in a self-custody wallet, it is important to understand how to move across to the new chain.

Why Did Fantom Become Sonic?

To understand the migration, it helps to look at what Sonic is trying to fix.

As blockchains grow, they collect massive amounts of historical data. Every transaction, of any size, must be recorded and stored. Over time this creates storage bloat.

On many networks, running a validator node (the computers that secure and verify the chain) starts to require expensive hardware and huge storage capacity. When only better resourced operators can afford to run nodes, the network can drift towards being more centralised.

The solution: validator pruning

Sonic tackles this storage problem with a process called validator pruning.

In simple terms, pruning lets a node discard older data that is no longer needed to verify new transactions. The node does not need the entire history to know whether a transaction is valid today.

Instead of keeping the full record of every payment ever made, a Sonic validator mainly stores the current “world state”, which is a snapshot of who owns what right now, plus a relatively small window of recent blocks.

This pruning happens in real time, which helps the node stay light and fast while it processes new activity. The result is a network that is cheaper to run and, according to the project, capable of handling more than 10,000 transactions per second.

The Migration: Token Swap Details

The shift from FTM to S is a standard token swap where the old asset is replaced by a new one.

• The ratio: The swap occurs at a 1:1 ratio. For every 1 FTM you hold, you receive 1 S.
• The ticker: The new token symbol is S.
• The timeline: The migration began in late 2024. The ability to bridge tokens back and forth (two-way) ended on 18 March 2025. Since that date, the migration has been one-way only. You can convert FTM into S, but you cannot convert S back into FTM.
• Current status: As of February 2026, the official swap portal is still available for holders who have not yet migrated their FTM tokens.

How to Convert FTM to Sonic

Your migration process depends on where your FTM is currently stored.

1. For users on centralised exchanges

If your FTM was held on a major centralised exchange (CEX) during the migration period, the swap was probably handled for you.

Most large exchanges paused FTM deposits and withdrawals, took a snapshot of user balances, then credited accounts with the equivalent amount of S tokens once the upgrade was complete. Check your account history or current balances to confirm that your assets are now listed as S.

If you still see FTM in your exchange account, or your specific exchange did not support the migration, you may need to withdraw the FTM to a self-custody wallet and complete the swap through the official portal.

2. For users with hot wallets (self‑custody)

If you hold FTM in a wallet such as MetaMask, Trust Wallet, Phantom, or similar, you are responsible for completing the swap yourself.

Step-by-step guide

1. Locate the official portal
   Go to the official Sonic Labs migration portal. Always verify the URL through Sonic’s official documentation or verified social media channels. Avoid clicking random links in comments, messages, or paid ads.

2. Connect your wallet
   Click the connect button and select your wallet provider. Make sure your wallet is set to the Fantom Opera network so the portal can detect your FTM balance.

3. Approve the transaction
   Your wallet will prompt you to sign an approval transaction. This allows the migration smart contract to access your FTM tokens. Check that the contract address matches the one listed in Sonic’s official documentation before you approve.

4. Swap your tokens
   Enter the amount of FTM you wish to convert and click the upgrade or swap button. You will need to sign a second transaction to complete the swap. This will cost a small amount of FTM as gas.

5. Add the Sonic network
   After the swap, your FTM balance will fall and your S balance will rise. You may need to manually add the Sonic network details to your wallet to see your S tokens. Sonic’s official docs should include the correct RPC, chain ID, and block explorer link.

How It Works in Practice: The Execution Client

The upgrade changes how the network processes transactions at a deep technical level.

In the previous Fantom setup, the “execution client”, which is the software that runs smart contracts, could become a bottleneck when traffic spiked. Heavy usage on decentralised exchanges (DEXs) or NFT markets could slow everything down.

Sonic introduces a new execution environment that is designed to process many transactions in parallel. For a user trading on a DEX or interacting with a lending protocol, this should mean faster confirmations and a smoother experience, even when the network is busy.

By migrating to S, you are moving your assets from an older engine to a modern system that separates storage duties from transaction processing in a more efficient way.

Risks and Red Flags

Token migrations are a prime time for scams. Attackers know that users are actively searching for links, instructions, and support.

• Fake migration portals
  Scammers often buy sponsored ads on search engines or social media that lead to fake versions of the migration portal. These sites can look almost identical to the real one, but if you connect your wallet they may attempt to drain it. Always type in known URLs or use links from official Sonic channels.

• Unsolicited support
  Legitimate support teams will not DM you first on platforms such as X (formerly Twitter), Discord, or Telegram offering to “help” you migrate. These messages are usually social engineering attempts to trick you into sharing wallet access or signing harmful transactions.

• Malicious approvals
  Be cautious when granting permissions in your wallet. If a site asks for unlimited access to your stablecoins, NFTs, or other tokens that are not part of the migration, reject the transaction. Check the token contract approvals in your wallet regularly and revoke anything that looks suspicious or unnecessary.

The Future of Sonic

The move to Sonic is more than a rebrand. It is a strategic shift that aims to keep the network competitive against other high-speed blockchains.

By addressing state bloat and lowering the hardware requirements for running a validator, Sonic is aiming to position itself as a strong base for high-performance decentralised finance (DeFi) applications and other intensive on-chain activity.

For individual users, the immediate priority is straightforward. Make sure your FTM is safely converted to S through the official channels. Once you have migrated, your tokens sit on a faster, pruned network that has been built to support the next generation of on-chain use cases.