The only genuinely bidirectional tool we evaluated: the MK808S reads every major module (engine, transmission, ABS, TPMS, BCM), runs 3,000+ active component tests and handles 28+ reset services on a dedicated Android tablet. Overkill for a check-engine light, right at home for a serious DIYer or side-shop. Note this is the S revision — the original MK808 is the older, shallower tool and is what most stale round-ups still link.

The most-reviewed scanner in the category by a wide margin, and the app is why: enhanced ABS/SRS/airbag reads plus vehicle-specific Repair Reports drawn from a database of verified fixes. The dongle needs your phone, so there's no standalone screen.

The sweet-spot standalone unit: a color screen, one-click I/M readiness for emissions checks, and graphable live engine data without needing a phone. Engine-system only, so it won't touch ABS or airbag faults.

Researched as the honest successor to the discontinued AL319 we used to recommend. Autel's AL329 keeps the one-click I/M readiness check that makes it genuinely useful at emissions time, adds AutoVIN and Mode 6, and graphs live data on any 1996-or-newer OBD-II vehicle. It's a standalone handheld with no app or subscription, rated 4.7/5 by owners. Not bidirectional, so it diagnoses and clears codes rather than commanding components.