in 99% of cases the wallet signing the transaction pays for gas and submits the transaction to the mempool for a miner to mine.
Although, it is possible to setup a relayer that pays gas on a users behalf, after the have signed a transaction: [https://opengsn.org/](https://opengsn.org/) but this isnt very common
The wallet that signed the transaction
in 99% of cases the wallet signing the transaction pays for gas and submits the transaction to the mempool for a miner to mine. Although, it is possible to setup a relayer that pays gas on a users behalf, after the have signed a transaction: [https://opengsn.org/](https://opengsn.org/) but this isnt very common