Stonex STX-AG400 review
A focused Android guidance system with RTK positioning and broad ISOBUS support.
Reviewed by iTechGuides Editors · Editorial team · Updated Nov 2026
Stonex STX-AG400 is a GNSS guidance and auto-steering system for agricultural machinery, including tractors, transplanters, sprayers and harvesters. It is aimed at operators who need machine guidance, field management and implement-control support. The Android software offers automatic steering as well as AG400 Lite visual manual guidance, with tractor and implement configuration and calibration for precision-farming tasks.
For guidance work, STX-AG400 supports creation and management of guidance lines and field boundaries, with AB, A+, curved, pivot, mixed, headland and diagonal route patterns. Its stated RTK positioning accuracy is ±2.5 cm. Basic and Smart U-turn functions are included. Together, these options suit operations that need multiple route types and repeatable machine guidance, rather than a general-purpose farm platform. The product is listed for cloud and mobile deployment, while its software platform is Android.
ISOBUS support is a notable fit for operators coordinating guidance with compatible implement-control functions: the listed protocols are UT, TC-SC, TC-GEO, TC-BAS and AUX. Stonex offers email and phone support, and pricing is available by request. The focused feature set and Android platform make STX-AG400 a candidate for farms prioritizing auto-steering, field boundaries and ISOBUS capability. Buyers seeking broader farm-management functions or software beyond Android should compare alternatives before choosing it.
Stonex STX-AG400 pros and cons
- Where it wins
- RTK positioning with stated accuracy of ±2.5 cm
- Supports AB, curved, pivot, headland and other route patterns
- ISOBUS UT, TC-SC, TC-GEO, TC-BAS and AUX support
- Where it doesn't
- Focused on guidance rather than a broad farm-management suite
- Android-only software
- Pricing is available by request
Stonex STX-AG400 fact sheet, pricing and score →
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