Honest answer: they're both good at different things, and plenty of people use both. Here's the practical split.
Suno's strengths: vocals and lyrics — it sings your words more intelligibly, handles song structure (verse/chorus/bridge) reliably, and the workflow (Extend, Replace Section, Personas) is built for songwriters iterating fast.
Udio's strengths: often praised for raw audio fidelity and musical nuance — some producers prefer its instrumental realism and mix polish out of the gate.
How to choose: if you're a songwriter who cares about lyrics landing and structures working, start with Suno. If you're chasing the most 'expensive-sounding' instrumental audio, try Udio's free tier and compare the same prompt on both.
The real move: generate on both, keep the winner. Some folks write in Suno and produce in Udio, or vice versa. There's no loyalty oath — use the tool that serves the song.
Don't trust fanboy wars. Most 'X DESTROYS Y' posts are engagement bait. Your ears, your call.
Good luck! Hank founder of SonorixPG