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Data

GPT-6 Luna vs Step 5 Preview

Updated November 6, 2026. Rank says GPT-6 Luna is ahead. Price, access, and your workload can each overturn that. Public scores include evidence status and uncertainty.

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Decision reading

GPT-6 Luna has the higher public point estimate, 62.59 versus 56.83. Their conditional score ranges overlap. These ranges do not establish rank confidence. 3 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A
OpenAI logo
GPT-6 Luna

OpenAI

62.59/100

Supported · Public rank #43

90% interval 52.0–73.2

Model B
StepFun logo
Step 5 Preview

StepFun

56.83/100

Estimated · Public rank #61

Conditional range 47.1–66.5

Shared results
3
GPT-6 Luna only
20
Step 5 Preview only
21
Like-for-like categories
1 / 8
Supported: GPT-6 Luna · Estimated: Step 5 Preview. Conditional ranges do not establish rank confidence.How the comparison works

Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

  • Long documents

    Prompts that approach the documented context limit

    GPT-6 Luna

    GPT-6 Luna has the larger documented context window.

    Confidence: documented

  • Chat turn cost

    1K fresh input + 500 output tokens

    GPT-6 Luna

    GPT-6 Luna has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    GPT-6 Luna

    GPT-6 Luna has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
Show secondary and unsupported calls

  • Repository review cost

    50K fresh input + 3K output tokens

    GPT-6 Luna

    GPT-6 Luna has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Coding work

    Code generation, repair, and software-engineering tasks

    Not enough matched evidence

    Step 5 Preview is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like.

    Confidence: limited

  • Agentic work

    Tool use, computer use, and multi-step task completion

    Not enough matched evidence

    GPT-6 Luna and Step 5 Preview are scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.

    Confidence: limited

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

51.8GPT-6 Luna49.2Step 5 Preview

Directional only · BenchAlign v5.8

GPT-6 Luna has the higher coding point estimate. Conditional score ranges do not establish rank confidence.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

Open the coding leaderboardShortlist models for this job
Same basis rules as the category table below

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

2 categories rest on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

A shared-evidence shape is not available.

BenchLM does not draw a radar or infer missing axes when the matched evidence is too sparse.

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign v5.8 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Knowledge

Like-for-like
GPT-6 Luna
63.3
Supported · #40/178
Step 5 Preview
61.0
Supported · #44/178
Basis
BenchAlign v5.8 lane · 5 vs 2 public rows
Reading
GPT-6 Luna leads · intervals overlap

Agentic

Directional only
GPT-6 Luna
53.5
Estimated · #45/131
Step 5 Preview
54.8
Estimated · #43/131
Basis
BenchAlign v5.8 lane · 5 vs 13 public rows
Reading
Directional only

Coding

Directional only
GPT-6 Luna
51.8
Supported · #42/157
Step 5 Preview
49.2
Estimated · #48/157
Basis
BenchAlign v5.8 lane · 3 vs 6 public rows
Reading
Directional only

Reasoning

Not comparable
GPT-6 Luna
57.5
#22/25
Step 5 Preview
80.8
Unranked · 2 rankable rows
Basis
Provisional lane · 2 vs 0 weighted rows
Reading
Not comparable

Multimodal

Not comparable
GPT-6 Luna
81.9
Unranked · 1 rankable row
Step 5 Preview
72.3
#34/59
Basis
Provisional lane · 0 vs 2 weighted rows
Reading
Not comparable

Multilingual

Not comparable
GPT-6 Luna
Not ranked
Step 5 Preview
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Instruction following

Not comparable
GPT-6 Luna
Not ranked
Step 5 Preview
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Math

Not comparable
GPT-6 Luna
80.2
Unranked · 2 rankable rows
Step 5 Preview
Not ranked
Basis
Provisional lane · 2 vs 0 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.8) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Supported evidence per lane · bars run 0–100Methodology

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

GPT-6 Luna
$0.00035
Fits in one request
Step 5 Preview
$0.00235
Fits in one request

GPT-6 Luna has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

GPT-6 Luna
$0.0065
Fits in one request
Step 5 Preview
$0.0581
Fits in one request

GPT-6 Luna has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

GPT-6 Luna
$0.009
Fits in one request
Step 5 Preview
$0.057
Fits in one request

GPT-6 Luna has the lower modeled cost

Costs use the listed standard API rates.

Cached input falls back to the list input rate only where a cached rate is unpublished

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Reasoning profile

GPT-6 Luna

Reasoning

Step 5 Preview

Reasoning

Weight access

GPT-6 Luna

Proprietary

Step 5 Preview

Open Weight

License

GPT-6 Luna

Proprietary

Step 5 Preview

Open Weight

Release date

GPT-6 Luna

2026-09-22

Step 5 Preview

2026-09-20

If you already use one of these models

Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
GPT-6 Luna has the higher public point estimate, 62.59 versus 56.83. Their conditional score ranges overlap. These ranges do not establish rank confidence.
Workload cost
Repository review: $0.0065 vs $0.0581. Cache-heavy agent loop: $0.009 vs $0.057.
Context tradeoff
GPT-6 Luna has the larger documented window (1.05M).
Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, GPT-6 Luna or Step 5 Preview?

GPT-6 Luna has the higher public point estimate, 62.59 versus 56.83. Their conditional score ranges overlap. These ranges do not establish rank confidence. The page therefore keeps the decision tied to the specific documented workload.

Which is better for coding, GPT-6 Luna or Step 5 Preview?

GPT-6 Luna scores higher for coding on the public lane, 51.8 to 49.2. Step 5 Preview is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like. BenchLM does not name a winner for coding from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which is better for agentic tasks, GPT-6 Luna or Step 5 Preview?

Step 5 Preview scores higher for agentic tasks on the public lane, 54.8 to 53.5. GPT-6 Luna and Step 5 Preview are scored on Estimated evidence for agentic tasks, so the reading is directional rather than like-for-like. BenchLM does not name a winner for agentic tasks from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which costs less, GPT-6 Luna or Step 5 Preview?

For the stated presets, chat costs $0.00035 on GPT-6 Luna and $0.00235 on Step 5 Preview; repository review costs $0.0065 and $0.0581; the cache-heavy agent loop costs $0.009 and $0.057. Costs use the listed standard API rates.

Which has the larger context window, GPT-6 Luna or Step 5 Preview?

GPT-6 Luna has the larger documented context window: 1.05M, compared with 1M.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

GPT-6 Luna
API / mo$450
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Step 5 Preview
API / mo$2,775
Self-host / mo$27,962
Break-even617M/day
Model the full break-even

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence44 rows

Agentic

  • ExploitGym

    GPT-6 Luna11.6%
    Source
    Step 5 Preview—

    Not directly comparable

  • Hermes Index

    Shared source
    GPT-6 Luna33.9%
    Step 5 Preview32.8%

    GPT-6 Luna leads this result

  • Hermes Bench

    Shared source
    GPT-6 Luna70.5%
    Step 5 Preview69.2%

    GPT-6 Luna leads this result

  • MazeBench

    GPT-6 Luna0%
    Source
    Step 5 Preview—

    Not directly comparable

  • OSWorld 2.1 Offline

    GPT-6 Luna48.9%
    Source
    Step 5 Preview—

    Not directly comparable

  • Terminal-Bench 2.1

    GPT-6 Luna—
    Step 5 Preview85.0%
    Source

    Not directly comparable

  • Terminal-Bench 4.0

    GPT-6 Luna—
    Step 5 Preview33.30%
    Source

    Not directly comparable

  • CyberGym

    GPT-6 Luna—
    Step 5 Preview84.7%
    Source

    Not directly comparable

  • AutomationBench

    GPT-6 Luna—
    Step 5 Preview44.0%
    Source

    Not directly comparable

  • Toolathlon-Verified

    GPT-6 Luna—
    Step 5 Preview74.1%
    Source

    Not directly comparable

  • MCP Atlas

    GPT-6 Luna—
    Step 5 Preview85.6%
    Source

    Not directly comparable

  • JobBench

    GPT-6 Luna—
    Step 5 Preview59.0%
    Source

    Not directly comparable

  • APEX-Agents

    GPT-6 Luna—
    Step 5 Preview37.8%
    Source

    Not directly comparable

  • DRACO

    GPT-6 Luna—
    Step 5 Preview83.3%
    Source

    Not directly comparable

  • BrowseComp

    GPT-6 Luna—
    Step 5 Preview88.7%
    Source

    Not directly comparable

  • Agents' Last Exam

    GPT-6 Luna—
    Step 5 Preview29.5%
    Source

    Not directly comparable

Coding

  • DeepSWE

    GPT-6 Luna66.6%
    Source
    Step 5 Preview67.7%
    Source

    Step 5 Preview leads this result

  • Bug Hunt Bench

    GPT-6 Luna18.3 fixes
    Source
    Step 5 Preview—

    Not directly comparable

  • FrontierCode 2.0

    GPT-6 Luna21.9%
    Source
    Step 5 Preview—

    Not directly comparable

  • Terminal-Bench 2.1

    GPT-6 Luna—
    Step 5 Preview85.0%
    Source

    Not directly comparable

  • SciCode

    GPT-6 Luna—
    Step 5 Preview58.9%
    Source

    Not directly comparable

  • ProgramBench

    GPT-6 Luna—
    Step 5 Preview80.5%
    Source

    Not directly comparable

  • sweMarathon

    GPT-6 Luna—
    Step 5 Preview72.7%
    Source

    Not directly comparable

  • MLS-Bench Lite

    GPT-6 Luna—
    Step 5 Preview40.5%
    Source

    Not directly comparable

Reasoning

  • BioBasicsBench

    GPT-6 Luna37.6%
    Source
    Step 5 Preview—

    Not directly comparable

  • ARC-AGI-1

    GPT-6 Luna86.67%
    Source
    Step 5 Preview—

    Not directly comparable

  • ARC-AGI-2

    GPT-6 Luna59.3%
    Source
    Step 5 Preview—

    Not directly comparable

  • ARC-AGI-3

    GPT-6 Luna0.1%
    Source
    Step 5 Preview—

    Not directly comparable

  • ARC-AGI-3 Provider Adapter

    GPT-6 Luna0.59%
    Source
    Step 5 Preview—

    Not directly comparable

  • CritPt

    GPT-6 Luna—
    Step 5 Preview20.9%
    Source

    Not directly comparable

Multimodal

  • ExtractBench Pro

    GPT-6 Luna0%
    Source
    Step 5 Preview—

    Not directly comparable

  • ExtractBench (LlamaIndex)

    GPT-6 Luna91.01%
    Source
    Step 5 Preview—

    Not directly comparable

  • ParseBench

    GPT-6 Luna64.13%
    Source
    Step 5 Preview—

    Not directly comparable

  • OfficeQA Pro

    GPT-6 Luna—
    Step 5 Preview60.3%
    Source

    Not directly comparable

  • MMMU-Pro

    GPT-6 Luna—
    Step 5 Preview76%
    Source

    Not directly comparable

Knowledge

  • HealthBench (raw)

    GPT-6 Luna50.0%
    Source
    Step 5 Preview—

    Not directly comparable

  • HealthBench (length-adjusted)

    GPT-6 Luna54.5%
    Source
    Step 5 Preview—

    Not directly comparable

  • HealthBench Professional

    GPT-6 Luna60.8%
    Source
    Step 5 Preview—

    Not directly comparable

  • HealthBench Professional (raw)

    GPT-6 Luna61.2%
    Source
    Step 5 Preview—

    Not directly comparable

  • HealthBench Hard

    GPT-6 Luna31.4%
    Source
    Step 5 Preview—

    Not directly comparable

  • GPQA-D

    GPT-6 Luna—
    Step 5 Preview93.5%
    Source

    Not directly comparable

  • HLE

    GPT-6 Luna—
    Step 5 Preview46.5%
    Source

    Not directly comparable

Math

  • FrontierMath v2 (Tiers 1-3)

    GPT-6 Luna78.947%
    Source
    Step 5 Preview—

    Not directly comparable

  • FrontierMath v2 (Tier 4)

    GPT-6 Luna56.098%
    Source
    Step 5 Preview—

    Not directly comparable

44 public results · 3 shared

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Last updated November 6, 2026