Do all caterpillars turn into butterflies?

Yes, but some turn into moths.
Before I answer I must say you should rephrase the question to: Do all species of caterpillars transform into butterflies, because the simplest answer would be no, because some will get eaten, stepped on, etc... and will not undergo transformation.

As well as hawk-moth caterpillars, atlas-moth caterpillars and silk-moth caterpillars which by name they turn into moths.