足立レイ (Adachi Rei) vs Darwin-OP
Side-by-side comparison of 足立レイ (Adachi Rei) (Mechanical Girl) and Darwin-OP (ROBOTIS Co., Ltd.) — specs, pricing, Robo Index, and verified deployments. Updated daily.
Optimize comparison for buyer
Optimized for Home & Household buyers. Priority specs lifted to the top and marked with a target.
Layer 1: Identity & Trust
Manufacturer Country
- 足立レイ (Adachi Rei)Japan
- Darwin-OPSouth Korea
Year First Available
- 足立レイ (Adachi Rei)2022
- Darwin-OP2010
Verified Deployments
- 足立レイ (Adachi Rei)0 Deployments
- Darwin-OP0 Deployments
Layer 2: Operational
Price
- 足立レイ (Adachi Rei)$1,000 USD
- Darwin-OP$12,000 USD
Battery / Shift Runtime
- 足立レイ (Adachi Rei)—
- Darwin-OP0.5 hrs
Availability Status
- 足立レイ (Adachi Rei)ACTIVE
- Darwin-OPACTIVE
Physical Form Factor
Weight
- 足立レイ (Adachi Rei)20 kg
- Darwin-OP9.1 kg
Height
- 足立レイ (Adachi Rei)168 mm
- Darwin-OP45.72 cm
Mobility Type
- 足立レイ (Adachi Rei)—
- Darwin-OPbipedal
Humanoid Subtype
- 足立レイ (Adachi Rei)digital avatar
- Darwin-OPfull bipedal
Walking Speed
- 足立レイ (Adachi Rei)—
- Darwin-OP0.2 m/s
Stair Climbing
- 足立レイ (Adachi Rei)—
- Darwin-OPNo
Terrain
- 足立レイ (Adachi Rei)both
- Darwin-OPflat indoor
Payload & Dexterity
Total DOF
- 足立レイ (Adachi Rei)—
- Darwin-OP20
Arm DOF
- 足立レイ (Adachi Rei)—
- Darwin-OP3
Bimanual Coordination
- 足立レイ (Adachi Rei)—
- Darwin-OPNo
Compute & AI
Onboard Compute
- 足立レイ (Adachi Rei)Intel i7-7567U @ 3.5GHz
- Darwin-OPIntel Atom N2600 @1.6 GHz dual core
VLM Capable
- 足立レイ (Adachi Rei)—
- Darwin-OPNo
Foundation Models
- 足立レイ (Adachi Rei)—
- Darwin-OPfalse
Imitation Learning
- 足立レイ (Adachi Rei)—
- Darwin-OPNo
Programming
- 足立レイ (Adachi Rei)code_python, no_code_gui
- Darwin-OPcode_python, code_ros
Battery & Power
Runtime
- 足立レイ (Adachi Rei)—
- Darwin-OP0.5 hrs
Battery Swap
- 足立レイ (Adachi Rei)—
- Darwin-OPNo
Software
SDK Languages
- 足立レイ (Adachi Rei)code_python, no_code_gui
- Darwin-OPC++
ROS Support
- 足立レイ (Adachi Rei)—
- Darwin-OPYes
Open API
- 足立レイ (Adachi Rei)—
- Darwin-OPYes
Reliability
Deployment Maturity
- 足立レイ (Adachi Rei)commercial
- Darwin-OPcommercial
Commercial
Price (USD)
- 足立レイ (Adachi Rei)$1,000 USD
- Darwin-OP$12,000 USD
Price Tier
- 足立レイ (Adachi Rei)<10K
- Darwin-OP10-20K
Pricing Model
- 足立レイ (Adachi Rei)outright purchase
- Darwin-OPpurchase
Warranty
- 足立レイ (Adachi Rei)—
- Darwin-OP1 yrs
Applications
- 足立レイ (Adachi Rei)teleoperation
- Darwin-OPeducation, research
| | |
|---|---|---|
| Layer 1: Identity & Trust | ||
| Manufacturer Country (values differ) | Japan | South Korea |
| Year First Available (values differ) | 2022 | 2010 |
| Verified Deployments | 0 Deployments | 0 Deployments |
| Layer 2: Operational | ||
| Price (values differ) | $1,000 USD | $12,000 USD |
| Battery / Shift Runtime (priority for Home & Household buyers) (values differ) | — | 0.5 hrs |
| Availability Status | ACTIVE | ACTIVE |
| Layer 3: Category Specific | ||
| Physical Form Factor | ||
| Weight (priority for Home & Household buyers) (values differ) | 20 kg | 9.1 kg |
| Height (values differ) | 168 mm | 45.72 cm |
| Mobility Type (values differ) | — | bipedal |
| Humanoid Subtype (values differ) | digital avatar | full bipedal |
| Walking Speed (values differ) | — | 0.2 m/s |
| Stair Climbing (values differ) | — | No |
| Terrain (values differ) | both | flat indoor |
| Payload & Dexterity | ||
| Total DOF (values differ) | — | 20 |
| Arm DOF (values differ) | — | 3 |
| Bimanual Coordination (values differ) | — | No |
| Compute & AI | ||
| Onboard Compute (values differ) | Intel i7-7567U @ 3.5GHz | Intel Atom N2600 @1.6 GHz dual core |
| VLM Capable (values differ) | — | No |
| Foundation Models (values differ) | — | false |
| Imitation Learning (values differ) | — | No |
| Programming (values differ) | code_python, no_code_gui | code_python, code_ros |
| Battery & Power | ||
| Runtime (values differ) | — | 0.5 hrs |
| Battery Swap (values differ) | — | No |
| Software | ||
| SDK Languages (values differ) | code_python, no_code_gui | C++ |
| ROS Support (values differ) | — | Yes |
| Open API (values differ) | — | Yes |
| Reliability | ||
| Deployment Maturity | commercial | commercial |
| Commercial | ||
| Price (USD) (values differ) | $1,000 USD | $12,000 USD |
| Price Tier (values differ) | <10K | 10-20K |
| Pricing Model (values differ) | outright purchase | purchase |
| Warranty (values differ) | — | 1 yrs |
| Applications (values differ) | teleoperation | education, research |
Insufficient data for full comparison
The following fields had no data for any of the selected robots: Running Capable, Payload, Payload (Peak), Hand DOF, Arm Reach, Grip Strength, Manipulation Repeatability, Tool Use, Compute Platform, Teleoperation, Battery Capacity, Charging Time, Charging Method, Avg Power Consumption, Force-Limited Arms, Fall Recovery, Fall Detection Response, Emergency Stops, Human Detection Method, Safe Speed Near Humans, Simulation Platforms, Air-Gap Capable, MTBF, Task Success Rate, IP Rating, Noise Level, RaaS / Month, Developer Unit Price, Delivery Lead Time, Production Pilots
ROI Comparison
Same operating assumptions across every robot — the only difference is price. Set your numbers once to see which pays back fastest.
Annual labor displaced (per robot): $50,000
| Metric | 足立レイ (Adachi Rei) | Darwin-OP |
|---|---|---|
| Investment | $1,000 | $12,000 |
| Payback period | < 1 mo | 2.9 mo |
| Net savings (5 yr) | $249,000 | $238,000 |
| ROI (5 yr) | +24900% | +1983% |
Estimates labor-cost displacement only — not a full total cost of ownership. Actual ROI depends on integration, maintenance, training, downtime, and task fit. Converted currencies are indicative; USD is the price of record.
Trade-offs at a glance
Frequently asked
Who makes 足立レイ (Adachi Rei) and Darwin-OP?
足立レイ (Adachi Rei) is made by Mechanical Girl, based in JP. Darwin-OP is made by ROBOTIS Co., Ltd., based in KR.
When were 足立レイ (Adachi Rei) and Darwin-OP launched?
足立レイ (Adachi Rei) launched in 2022. Darwin-OP launched in 2010.
How much does 足立レイ (Adachi Rei) cost compared to Darwin-OP?
足立レイ (Adachi Rei) is listed at $1,000. Darwin-OP is listed at $12,000.
How do 足立レイ (Adachi Rei) and Darwin-OP compare on the Robo Index?
足立レイ (Adachi Rei) grades BBB on the Robo Index. Darwin-OP grades AA. The Robo Index is a credibility grade (AAA … C) that blends commercial maturity, verified deployments, company standing, and independent coverage — see methodology for the full breakdown.
Are 足立レイ (Adachi Rei) and Darwin-OP in the same category?
Both robots are classified as Humanoid on Robolist. Filters and ranking treat them as direct alternatives.
What is the realistic total cost of ownership for Humanoid robots?
Hardware cost is one input. Humanoid TCO also includes integration, training, downtime, and end-of-life. Our breakdown: Humanoid TCO: Hardware, Cloud Subscriptions, and the Cost of Teleop Time.
What should a buyer ask vendors when choosing between 足立レイ (Adachi Rei) and Darwin-OP?
Spec sheets only show part of the story. Useful vendor questions cover support, lifecycle, integration cost, and references. We have a buyer-focused checklist: Vendor Selection for Humanoids: The 10 Questions You Must Ask.
Going deeper — picking the right robot
Humanoid TCO: Hardware, Cloud Subscriptions, and the Cost of Teleop Time
8 min readHumanoid Robots
Vendor Selection for Humanoids: The 10 Questions You Must Ask
10 min readHumanoid Robots
Running a Humanoid Pilot: Scope, Success Criteria, and Exit Options
9 min readHumanoid Robots
Build vs buy vs lease: which model fits a first deployment
8 min readChoosing Your First Robot
The hidden specs vendors hope you'll miss
10 min readReading the Spec Sheet
Want to be notified when specs or pricing change for these robots? Drop your email.
Other comparisons
About this comparison
足立レイ (Adachi Rei) vs Darwin-OP compares two robots in the humanoid category. All data is sourced from manufacturer spec sheets, verified deployments, and third-party filings; see our methodology for how the Robo Index is calculated.