You know you don’t really need tactical voting websites right?

1. If you don’t know it, google your town and “constituency”.
2. Look it up on Wikipedia. Format is “your constituency (UK Parliament constituency)”
3. Scroll down the page until you see the table for the 2017 election results.
   
4. If you like the party in first place, vote for them. If you don’t, then vote for the party in second place (or the highest polling one that you find most acceptable).

Here’s mine as an example.