How they really differ
Both have free tiers and paid plans, and the feature split between tiers changes over time, so compare current plans rather than old reviews.
Neither guarantees views. Their scores are guidance, and the creative angle of the video still does most of the work.
Using both
You rarely need both. Install each free version, see which one you open more, and keep that one.
The verdict
TubeBuddy for upload workflow, vidIQ for research. The free tiers make this an easy one to test.
Want the full write-up on each? Read our TubeBuddy review and vidIQ review.