What makes you click on a YouTube video? The thumbnail or the title?

I’ve been thinking a lot about thumbnails lately.

You can spend weeks making a great video…
but if the thumbnail doesn’t pull people in, it just doesn’t get clicked.

I’m curious how other makers and creators here approach this:

• Do you rely on intuition?

• Do you A/B test thumbnails?

• Do you focus more on the title or the image?

• Or do you just ship and iterate later?

While working on this problem, I ended up building Thumbnail AI, a tool that analyzes YouTube thumbnails for CTR signals (emotion, curiosity, contrast, clarity, etc.) and generates alternative versions before you publish.

Would love to hear your process (especially from non-YouTubers who still think about click-through a lot).