They mean the same thing often - strange and unusual. However, bizarre is usually used when something is extremely strange - so strange that you start to be nervous or afraid. A person coming to your informal party in a suit and tie would be a little weird. If that person came dressed in a suit made of paper, it would be bizarre.

They are like the same but bizarre seems stronger Like - You might say "that's weird" if your friend is being silly Weird can also be an insult Bizarre means crazy more than weird Like you might say "what a bizarre idea" if your friend said something crazy :)

See here: https://www.quora.com/What-is-the-difference-between-bizarre-strange-and-weird-in-the-following-phrases

bizarre is synonyms of weird. But bizarre is markedly unusual in appearance or style. And weird is unearthly or uncanny.