Contrast/Opposition:
* Nevertheless
* Nonetheless
* Still
* Yet
* But
* On the other hand
* Despite this
* In spite of this
* Conversely
* On the contrary
Concession:
* Although
* Though
* Even though
* While
* Whereas
Adding Information:
* Furthermore
* Moreover
* Besides
* In addition
Changing Direction:
* Anyway
* Anyhow
* At any rate
* In any case
The best synonym will depend on the specific context of your sentence.
For example:
* "I'm not sure if I can go, however, I'll try my best." Here, "nevertheless" could be a good substitute.
* "The weather is bad, however, we're still going to the beach." Here, "yet" or "but" might be more appropriate.
* "The movie was long, however, it was entertaining." Here, "although" or "though" could work well.
It's important to consider the flow of your sentence and the tone you want to convey when choosing a synonym for "however".