In general? I like to match all four. But I think in the right cirmunstances, this is absolutely a rule I would break. Maybe 2 and 2, with similar/same shapes and 2 coordinating fabrics could be fun. I could even envision an eclectic space with layers of carefully curated, collected pieces in which each of the 4 chairs was different but lent themselves perfectly toward coordinating with each other and the room.

In most cases, in most rooms, in most styles, I think it is more successful when all four match, and I think most people are happier with that. Do you have any specific chairs in mind or a picture of the space they would be going in?

I have a four chair conversation area in my home - four matching caramel leather chairs.

When I was deciding on chairs for my conversation area, most of the examples I found online used four matching chairs.

However, I did find some four chair conversation areas where two different sets of chairs were used instead of four matching ones. Typically, someone purchases the same chairs in two different fabrics/colors -

The above room was in a houzz post where OP was asking for help with new chairs for a conversation area.

OR - two different styIe chairs are used - but both sets have been upholstered in the same, or very similar, fabric:

The next photo uses two leather chairs + matching chairs in a cream fabric:

Below are similar style chairs in different fabrics. It seems like people will choose to do this when they have one set of chairs that they like - so, they find another set of chairs that will work with the existing ones OR if they've hired a designer to select chairs that will complement each other:

Personally, I would prefer all four matching OR chairs that don't match but either work together because they are similar style or use the same fabric. I don't really like the ones where four of the same chairs are used - but in different colors/types of fabric.

Thank you Dani and Melissa.

I like Best Furniture Kaylee swivel chairs. The room is a recently enclosed lanai, dining chairs and bench in the photo are for space considerations.