The 1inch Aggregation Protocol's upgraded v3 features optimization of gas usage.
The 1inch Aggregation Protocol v3 is available on both currently supported chains - Ethereum and Binance Smart Chain (BSC). Thanks to optimized assembly code, swaps executed through the Uniswap V2 protocol and its forks will require significantly lower gas cost, making trades with the 1inch Aggregation Protocol v3 cheaper than, for instance, with Uniswap V2, 0x and 1inch Aggregation Protocol's earlier version.
A decision on switching between the two protocol versions is up to the user, as it requires new approvals for each asset the user would want to trade and, consequently, additional gas costs. However, the 'Protocol Version' is set to v3 by default.
To be able to switch between protocol versions, you have to:
go to https://app.1inch.io/;
click on the 'Settings';
click on the 'Protocol Version' and select 'v3.0' or 'v2.0' if you would like to stay on the earlier version;
Please, note that for your convenience, there is an opportunity to pin the protocol version switcher to the main interface, so that you will no longer need to go to the settings. To do so:
click on the star sign next to "Protocol Version" and make sure the indicator turns grey.