4 & 5 string jazz basses - same size body?

[Angel]

Just a quick question - 4 & 5 string jazz basses , do they have the same size body dimensions?

[itu]

Not automatically. There are manufacturers who put bigger body to a 5- or 6-string bass. I find this a bit annoying, as the bigger usually means clumsiness and more weight.  But your luthier is your friend: you can ask for a smaller body, if you like. Just like Rhonda Smith did.

[Doctor J]

If you're asking about Fender then generally yes. It's cheaper to CNC one shape and the cases for Jazz basses are universal, they fit both 4s and  5s the same.