Every token account on Solana requires a small SOL deposit (~0.002 SOL) to stay open. When you swap or receive a new token for the first time, a token account is created and this rent is locked up.
Once you've sold or sent all of a token, the account is no longer needed - you can close it and reclaim the SOL rent.
In the Jupiter Wallet Extension,
- Head to the reclaim section (the ♺ icon)
- Select the token accounts you want to close and approve the transaction to get your rent back.
This process is completely safe. If you ever buy or receive that token again, a new token account will automatically be created for it.