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LADDER in detail

The full benchmark, results and data, for researchers. This page follows the paper, LADDER: A Long-Horizon Robot Manipulation Benchmark.

The benchmark

LADDER has 145 robot tasks. Each one is a single instruction with 1 to 10 steps (we call them subgoals). It measures how far today's robot systems get as instructions grow longer, on two robots in three simulators. There are three kinds of systems: a robot model (a vision-language-action policy trained on robot data) that acts directly, an AI model that plans and gives the robot model one step at a time, and an AI agent that controls the arm through tools.

Controlled lengthWithin a scene, a longer task keeps every subgoal of a shorter one and adds more (138 of the 145 tasks). The effect of instruction length is measured directly.
Many kinds of instructionsEight task categories: moving objects to one or several destinations, in a given order, through an intermediate stop, or leaving some objects in place.
Every subgoal is checkedEach subgoal is checked automatically. Results report full-task success and the share of subgoals completed.
145tasks
3simulators
8task categories
1–10subgoals per task
10systems evaluated
2real robots
RoboLab-Long: GPT-Policy, 7 subgoals GPT-Policy · 7 subgoals 4× speed

RoboLab-Long

44 tasks · Isaac Sim · Franka FR3

low-level policy: π0.5 (DROID)

SimplerEnv-Long: GPT-Policy, 10 subgoals GPT-Policy · 10 subgoals 4× speed

SimplerEnv-Long

54 tasks · SAPIEN · WidowX 250

low-level policy: Bridge policy

RobotArena--Long: GPT-Policy, 8 subgoals GPT-Policy · 8 subgoals 4× speed

RobotArena-∞-Long

47 tasks · Genesis · WidowX 250

low-level policy: Bridge policy

Eight task categories

What one instruction asks for.

Single destination

Single destination 44 tasks

Every object goes to the same destination.

“put both carrots, the spoon and the eggplant on the plate”

Transfer

Transfer 8 tasks

Every object starts on one destination and is moved to another.

“move the carrot and the spoon from the plate to the blue towel”

Split destination

Split destination 25 tasks

Different objects go to different destinations.

“put the lemon on the plate and put the orange in the bin”

Relay

Relay 20 tasks

Objects pass through an intermediate destination.

“first put the carrot on the plate, then put the carrot on the blue towel”

Revisit

Revisit 13 tasks

Objects return to a destination they have already left.

“first put the spoon on the cloth, then put the spoon in the pot, then put the spoon on the cloth”

Exclusion

Exclusion 13 tasks

Some objects must be left where they are.

“put everything except the eggplant on the plate”

Ordered

Ordered 14 tasks

The placements must occur in a stated order.

“first put the banana in the bin, then put the orange in the bin”

Duplicates

Duplicates 8 tasks

Several identical objects, so the instruction refers to them by count, not by name.

“put both corn cobs on the cloth”

Results

85.4% → 0.0%

Policies fail on long instructions

Given the full instruction, the low-level policy completes 85.4% of 1-subgoal tasks, 26.9% of 2-subgoal tasks and 0.0% of 5-subgoal tasks.

26.9% → 58.4%

One subgoal at a time helps

On 2-subgoal tasks, the same policy succeeds 58.4% of the time when an orchestrator gives it one subgoal at a time and checks each one with a VLM.

43.4% → 3.4%

Orchestrators must check progress

An orchestrator that moves on without checking skips up to 43.4% of subgoals before they are done. Checking with a VLM reduces this to 3.4%.

62.0%

The best system uses a frontier VLM

GPT-Policy, an agent driven by GPT-6 Astra, completes 62.0% of all episodes, the highest of all systems.

$6.49 vs $0.33

Its success costs 20 times more

GPT-Policy spends $6.49 on API calls per successful episode. PSP-Agent, second at 40.1%, spends $0.33.

27.3%

Agents hold up on long tasks

On 5-subgoal tasks, PSP-Agent still succeeds 27.3% of the time, more than the privileged verifier with the same low-level policy (11.1%).

The longer the task, the more often robots fail

0%25%50%75%100%12–34–56–78–10objects to move in one taskGPT-6 Astra (GPT-Policy): 92.0%GPT-6 Astra (GPT-Policy): 83.2%GPT-6 Astra (GPT-Policy): 62.6%GPT-6 Astra (GPT-Policy): 44.1%GPT-6 Astra (GPT-Policy): 34.8%Gemini 3.7 Flash (PSP-Agent): 80.9%Gemini 3.7 Flash (PSP-Agent): 63.6%Gemini 3.7 Flash (PSP-Agent): 40.3%Gemini 3.7 Flash (PSP-Agent): 24.0%Gemini 3.7 Flash (PSP-Agent): 8.9%Robot model alone: 87.2%Robot model alone: 21.1%Robot model alone: 3.5%Robot model alone: 2.3%Robot model alone: 0.8%0%25%50%75%100%12–34–56–78–10objects to move in one taskGPT-6 Astra (GPT-Policy): 92.0%GPT-6 Astra (GPT-Policy): 83.2%GPT-6 Astra (GPT-Policy): 62.6%GPT-6 Astra (GPT-Policy): 44.1%GPT-6 Astra (GPT-Policy): 34.8%Gemini 3.7 Flash (PSP-Agent): 80.9%Gemini 3.7 Flash (PSP-Agent): 63.6%Gemini 3.7 Flash (PSP-Agent): 40.3%Gemini 3.7 Flash (PSP-Agent): 24.0%Gemini 3.7 Flash (PSP-Agent): 8.9%Robot model alone: 87.2%Robot model alone: 21.1%Robot model alone: 3.5%Robot model alone: 2.3%Robot model alone: 0.8%
GPT-6 Astra (GPT-Policy)Gemini 3.7 Flash (PSP-Agent)Robot model alone

Share of tasks finished. Every model is on the leaderboard, under Details.

Cost

What each system spends on AI model calls.

An agent that calls a frontier model at every step is the most successful system, and by far the most expensive. One full evaluation of GPT-Policy costs up to $8,134 in API calls.

Cost is measured from each provider's own token counts, at list prices. The robot policy runs on a local GPU and is not included.

SystemModelModel calls per episode Cost per episodeCost per success
GPT-PolicyGPT-6 Astra54$4.02$6.49
VoLoGemini 3.7 Flash23$0.17$0.66
PSP-AgentGemini 3.7 Flash23$0.13$0.33
Proprioceptive verifierGemini 3.7 Flash10$0.045$0.18
CaP-XGemini 3.7 Flash5$0.043$0.17
TiPToPGemini 3.7 Flash1$0.007$0.07
42.1% / 49.5%

More time would not help much

The Proprioceptive verifier completes 42.1% of all subgoals in the first half of the time limit, and only 49.5% by the end.

36–45%

Successful episodes finish early

Successful episodes of the systems built on a low-level policy use 36–45% of the time limit on average.

Per simulator

Model calls, tokens, cost and subgoals completed, for each system.

Low-level policyPeriodic triggerProprioceptive triggerProprioceptive verifierVoLoCaP-XTiPToPPSP-AgentGPT-PolicyPrivileged verifier
VLM calls per episode
RoboLab-Long0.00.00.09.319.26.31.031.870.80.0
SimplerEnv-Long0.00.00.012.724.83.81.018.050.10.0
RobotArena-∞-Long0.00.00.09.326.45.61.020.241.70.0
VLM calls per completed subgoal
RoboLab-Long0.00.00.03.26.02.90.97.517.40.0
SimplerEnv-Long0.00.00.04.910.11.62.86.111.80.0
RobotArena-∞-Long0.00.00.07.322.25.12.110.713.30.0
Input tokens per episode (thousands)
RoboLab-Long0.00.00.023.691.615.32.148.5508.80.0
SimplerEnv-Long0.00.00.017.270.57.52.027.3357.80.0
RobotArena-∞-Long0.00.00.012.675.012.92.031.2293.50.0
Generated tokens per episode (thousands)
RoboLab-Long0.00.00.02.57.25.10.416.48.30.0
SimplerEnv-Long0.00.00.02.77.43.10.510.45.70.0
RobotArena-∞-Long0.00.00.01.86.64.60.410.14.90.0
API cost per episode (USD)
RoboLab-Long0.0000.0000.0000.0540.1910.0610.0060.1965.5010.000
SimplerEnv-Long0.0000.0000.0000.0460.1610.0340.0070.1193.8610.000
RobotArena-∞-Long0.0000.0000.0000.0320.1620.0540.0060.1233.1770.000
API cost per successful episode (USD)
RoboLab-Long0.000.000.000.210.660.300.040.388.760.00
SimplerEnv-Long0.000.000.000.180.630.120.100.326.400.00
RobotArena-∞-Long0.000.000.000.130.760.330.050.314.760.00
Subgoals completed by half of the time budget (%)
RoboLab-Long53.152.650.248.453.641.622.378.478.155.9
SimplerEnv-Long21.337.842.344.140.338.46.042.960.947.8
RobotArena-∞-Long10.525.424.424.626.719.412.637.960.224.4
Subgoals completed by the end of the budget (%)
RoboLab-Long56.657.158.956.162.042.422.481.678.763.3
SimplerEnv-Long25.339.945.851.048.345.97.158.283.352.4
RobotArena-∞-Long13.528.328.933.731.829.512.650.283.432.7

API cost at list prices; it covers only the hosted VLM.

Real robots

The same comparison on a real Franka and a real WidowX arm.

2 robots

WidowX 250 and Franka FR3

The low-level policy alone, the Proprioceptive verifier and PSP-Agent on tasks of 1 to 5 subgoals, 12 episodes per task and system.

Same ranking

Simulation predicts the real ranking

On the physical robots the three systems rank in the same order as in simulation.

Task categorySubgoalsLow-level policyProp. verifierPSP-Agent
Franka
Single destination50.08.325.0
Exclusion20.083.3100.0
Ordered316.783.3100.0
WidowX
Single destination166.775.0100.0
Single destination2–30.033.387.5
Split destination2–30.029.283.3
Exclusion20.058.391.7
Ordered28.333.341.7
Duplicates20.00.058.3
0%25%50%75%100%Robot model alone, simulation: 19.6%Proprioceptive verifier, simulation: 25.6%Gemini 3.7 Flash via PSP-Agent, simulation: 51.4%SimulationRobot model alone, real robot: 5.6%Proprioceptive verifier, real robot: 58.3%Gemini 3.7 Flash via PSP-Agent, real robot: 75.0%RealRobot model alone, simulation: 9.8%Proprioceptive verifier, simulation: 24.7%Gemini 3.7 Flash via PSP-Agent, simulation: 38.5%SimulationRobot model alone, real robot: 15.7%Proprioceptive verifier, real robot: 40.7%Gemini 3.7 Flash via PSP-Agent, real robot: 81.5%RealFrankaWidowX0%25%50%75%100%Robot model alone, simulation: 19.6%Proprioceptive verifier, simulation: 25.6%Gemini 3.7 Flash via PSP-Agent, simulation: 51.4%SimulationRobot model alone, real robot: 5.6%Proprioceptive verifier, real robot: 58.3%Gemini 3.7 Flash via PSP-Agent, real robot: 75.0%RealRobot model alone, simulation: 9.8%Proprioceptive verifier, simulation: 24.7%Gemini 3.7 Flash via PSP-Agent, simulation: 38.5%SimulationRobot model alone, real robot: 15.7%Proprioceptive verifier, real robot: 40.7%Gemini 3.7 Flash via PSP-Agent, real robot: 81.5%RealFrankaWidowX
Robot model aloneProprioceptive verifierGemini 3.7 Flash via PSP-Agent

Real-robot rollouts

The three systems on the same tasks, 12 episodes each. Each clip is typical for its system on that task: a success if the system succeeds in at least half of its episodes, otherwise a failure that completed its median number of subgoals. Speeds are relative to the control rate (5 Hz WidowX, 15 Hz Franka); the real control loop ran somewhat slower than that.

2× speed

“Put the corn, the carrot, the eggplant, the blue cup and the banana in the bowl”

5 subgoalsfailure · 3 of 5 done

2× speed

“First put the blue cup in the bowl, then put the carrot in the bowl, then put the eggplant in the bowl”

3 subgoals

2× speed

“Put everything except the eggplant in the bowl”

2 subgoals

Why tasks fail

Which subgoals fail, and whether the planner or the robot policy caused it.

7.1%

With checking, the policy causes most failures

Only 7.1% of the Proprioceptive verifier's subgoals fail because of an orchestrator decision (13.8% for VoLo). Most failed subgoals never reach the target object.

28%

Failed episodes stop making progress

Half of the failed episodes complete no further subgoal after the first 28% of the time limit.

16.2%

Agents also report success too early

PSP-Agent marks 16.2% of its subgoals as done when they are not, and TiPToP finds no plan for 50.9% of its subgoals.

Why subgoals fail, per system

Subgoals not completed at the end of the episode, by cause. Left: one bar per system. Right: all systems together, by the number of subgoals in the task. Grey and black: a planner mistake; the other colours: what happened to the object.

Which AI model plans best?

Each model answers the questions an orchestrator asks, on 145 scenes and 562 labelled images, without running the robot. Gemini 3.7 Flash, used by the orchestrators above, has the best mean score (80.8%).

ModelPlanning
exact match
Completion
TP rate
Completion
TN rate
State tracking
all correct
Next subgoal
valid
Tokens
per query
Qwen3-VL-2B75.2 ±7.668.2 ±7.034.1 ±5.99.3 ±4.058.9 ±5.3–
Qwen3-VL-8B91.0 ±5.869.0 ±6.879.9 ±5.747.9 ±5.572.3 ±4.4–
Qwen3.5-9B86.9 ±6.544.4 ±6.396.9 ±2.511.7 ±3.763.2 ±4.85,173
Qwen3.8-27B91.0 ±5.876.2 ±6.384.8 ±4.358.2 ±4.879.3 ±4.11,904
Gemini 3.1 Pro89.7 ±6.054.8 ±6.696.0 ±2.968.7 ±4.375.2 ±4.5583
Gemini 3.7 Flash93.1 ±5.459.4 ±6.696.6 ±2.670.8 ±4.081.4 ±4.2412
Gemini Robotics-ER 290.3 ±5.954.0 ±6.597.8 ±2.369.6 ±4.276.6 ±4.1510
GPT-5.6 Sol93.1 ±5.472.8 ±6.386.4 ±4.356.4 ±4.782.0 ±4.3282
GPT-6 Astra91.7 ±5.771.1 ±6.286.4 ±4.453.2 ±5.185.4 ±4.0203
Claude Opus 590.3 ±5.968.6 ±6.687.9 ±4.161.0 ±4.779.8 ±4.4400

Scores in % with 95% intervals. Planning: the list of subgoals is exactly right. Completion: finished (TP) and unfinished (TN) subgoals judged correctly. State tracking: the status of every subgoal is right. Next subgoal: the proposed next step is valid.

Videos

Recorded attempts from the evaluation. The label on each video gives its playback speed.

44 tasks · Isaac Sim · Franka FR3 · low-level policy: π0.5 (DROID)

Highlights: long tasks solved without a single mistake

2× speed

CaP-X

“first put the orange in the bin, then put the pumpkin in the bin, then put the lychee in the bin, then put the lemon in the bin, then put the lime in the bin, then put the banana in the bin, then put the onion in the bin, then put the avocado in the bin”

8 subgoals

2× speed

GPT-Policy

“first put the lemon on the plate, then put the lemon in the bin, then put the lime on the plate, then put the lime in the bin, then put the banana on the plate, then put the banana in the bin”

6 subgoals

2× speed

GPT-Policy

“put the avocado, the banana and the lemon on the plate and put the orange, the lime and the onion in the bin”

6 subgoals

One scene, growing horizon

2× speed

“put the banana in the bin”

1 subgoal

2× speed

“put the banana, the orange, the lemon, the lime, the avocado and the onion in the bin”

6 subgoals

2× speed

“put the banana, both oranges, the lemon, the lime, the avocado, the onion, the lychee, the pumpkin and the pomegranate in the bin”

10 subgoals

Task categories

2× speed

Proprioceptive trigger

“move the orange, the lemon and the lime from the plate to the bin”

3 subgoalsTransfer

2× speed

Privileged verifier

“put everything except the red block and the blue block in the bin”

4 subgoalsExclusion

One task, every system

RoboLab-Long, 4 subgoals: “put the avocado and the banana on the plate and put the orange and the lime in the bin”. Episodes are sampled at random, so failures are shown where they occurred.

4× speed

Low-level policy

failure

4× speed

Periodic trigger

success

4× speed

Proprioceptive trigger

failure

4× speed

Proprioceptive verifier

failure

4× speed

VoLo

success

4× speed

CaP-X

success

4× speed

TiPToP

success

4× speed

PSP-Agent

success

4× speed

GPT-Policy

success

4× speed

Privileged verifier

success

The same policy, with and without an orchestrator

Given the whole instruction at once, the low-level policy stalls after the first subgoals. Driven by the Proprioceptive verifier, it completes the task.

Relay · 6 subgoals: “first put the lemon on the plate, then put the lemon in the bin, then put the lime on the plate, then put the lime in the bin, then put the banana on the plate, then put the banana in the bin”

4× speed

Low-level policy failure

4× speed

Proprioceptive verifier success

Ordered · 4 subgoals: “first put the orange in the bin, then put the lemon in the bin, then put the lime in the bin, then put the banana in the bin”

4× speed

Low-level policy failure

4× speed

Proprioceptive verifier success

Evaluate your system

Any policy, orchestrator or agent can join the leaderboard.

  1. Plug it in. Start from the example for your kind of system and replace the model.
  2. Run the suites. Evaluate every task of the three suites with the default number of episodes.
  3. Open a pull request. Add your episode logs. Every score is recomputed from them, so nothing is taken on trust.

Integration guide How to submit Request a model

Paper, code and data

BibTeX

@article{ladder2026,
  title   = {{LADDER}: A Long-Horizon Robot Manipulation Benchmark},
  author  = {Petkov, Petko and Albanese, Giuliano and Nikolov, Nikolay and Van Gool, Luc and Tremblay, Jonathan and Paudel, Danda Pani},
  journal = {arXiv preprint arXiv:2610.18053},
  year    = {2026},
  url     = {https://arxiv.org/abs/2610.18053}
}