Pick the LBR iiwa if you need seven axes and precise joint-torque sensing for research, force-controlled assembly or polishing; it comes in 7 kg and 14 kg versions with about 800 mm of reach. Pick the LBR iisy if you want a factory cobot that’s quick to set up: it has six axes, five versions from 3 to 15 kg with up to 1,300 mm of reach, and runs KUKA’s app-style iiQKA.OS2 software, relaunched in July 2026. Both are still on KUKA’s product pages, and neither has a published price.
LBR iisy vs LBR iiwa at a glance
| LBR iiwa | LBR iisy | |
|---|---|---|
| Axes | 7 | 6 |
| Versions | 7 R800, 14 R820 (plus cleanroom) | 3 R760, 6 R1300, 8 R930, 11 R1300, 15 R930 |
| Payload | 7 or 14 kg | 3–15 kg |
| Reach | 800–820 mm | 760–1,300 mm |
| Torque sensing | All 7 joints, ±2% of max torque | All 6 joints |
| Controller | KUKA Sunrise Cabinet | KR C5 micro-2 |
| Software | KUKA Sunrise software | iiQKA.OS2, hand guiding, wizards |
| Protection | IP54 | IP30 (3 kg) or IP54 |
Sources: KUKA’s LBR iiwa page and LBR iisy page, checked October 23, 2026. KUKA’s 2022 iiwa brochure lists repeatability of ±0.1 mm (7 R800) and ±0.15 mm (14 R820) and arm weights of 23.9 kg and 29.9 kg; the current iisy page doesn’t list repeatability or weight.
Why the seventh axis and torque sensors matter
A seven-axis arm can reach the same tool position with different elbow positions, so it can work around fixtures or a person’s arm the way a human arm does. The iiwa’s torque sensors in every joint, rated at ±2% of maximum torque, let it feel contact and control force, which is why it shows up in research labs, polishing, and assembly where parts must be pressed in gently. If your project depends on measured contact forces, our note on when force data is worth collecting shows how to decide.
The iisy also has torque sensors in all six joints and detects external forces in real time, which supports fenceless operation when a risk assessment allows it. It gives up the seventh axis for a wider payload range, longer reach and simpler setup.
Software: Java and research tools, or apps
The iiwa runs on the KUKA Sunrise Cabinet. KUKA describes its Sunrise.OS, on its page for the related LBR Med, as programmed in object-oriented Java through Sunrise.Workbench; that level of control suits research but takes longer to learn than app-style teaching. Confirm the exact software package for an iiwa with KUKA when you order.
The iisy runs iiQKA.OS2 on the compact KR C5 micro-2 controller, launched with the arm’s new generation on July 15, 2026. You teach it by hand guiding and templates, simulate cells in iiQWorks.Sim, and build custom components with iiQWorks.App Builder. KUKA said in 2022 that an iisy could be set up in under 90 minutes.
ROS 2 support
KUKA maintains official kuka_drivers for ROS 2 Humble and Jazzy, whose July 2026 changelog adds iiQKA.OS2 support, plus robot description packages for iisy models. For the iiwa, the widely used option is the community lbr_fri_ros2_stack, which connects ROS 2 and Python to the iiwa and LBR Med through KUKA’s Fast Robot Interface and is published in the Journal of Open Source Software. Check which interface options your controller is licensed for before relying on either.
Which to choose
- Research, force control or seven-axis dexterity: LBR iiwa.
- Factory tasks from 3 to 15 kg with quick setup: LBR iisy.
- Long reach (1.3 m) at mid payload: iisy 6 R1300 or 11 R1300.
- Cleanroom work: both offer cleanroom versions (iiwa both sizes; iisy 11 and 15 kg).
Both are sold through KUKA sales and integrators; our KUKA lineup guide covers the buying routes and ownership. For other cobot brands, see the cobot companies comparison, and for sizing any arm to a task, our arm selection guide.
KUKA product pages and ROS package index checked October 23, 2026.