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Model comparison

GPT-5.6 Luna vs GPT-5.6 Sol

Updated August 10, 2026. Public scores include evidence status and uncertainty. They are not guarantees for a specific workload. This is a same-family comparison, so migration details appear when the source data supports them.

GPT-5.6 Luna

OpenAI

66.9/100

Estimated · Public rank #23

90% interval 56.4–77.3

GPT-5.6 Sol

OpenAI

81.5/100

Supported · Public rank #4

90% interval 77.7–85.3

GPT-5.6 Sol has the higher public score, 81.48 versus 66.87, and the 90% score intervals do not overlap.

22 results are shared. Category rows based on different benchmark sets are marked directional and do not name a winner.

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.

  • Coding work

    Code generation, repair, and software-engineering tasks

    GPT-5.6 Sol

    GPT-5.6 Sol leads on the same 1 weighted benchmark row.

    Confidence: limited

  • Agentic work

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

    GPT-5.6 Sol

    GPT-5.6 Sol leads on the same 2 weighted benchmark rows.

    Confidence: limited

  • Chat turn cost

    1K fresh input + 500 output tokens

    GPT-5.6 Luna

    GPT-5.6 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
  • Cache-heavy agent loop cost

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

    GPT-5.6 Luna

    GPT-5.6 Luna has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Repository review cost

    50K fresh input + 3K output tokens

    GPT-5.6 Luna

    GPT-5.6 Luna has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Long documents

    Prompts that approach the documented context limit

    No clear pick

    The documented context windows are equal.

    Confidence: documented

What is actually comparable

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

Shared results
22
GPT-5.6 Luna only
0
GPT-5.6 Sol only
2
Like-for-like categories
6 / 8

Category results, on a stated basis

Each row states whether both averages use the same weighted benchmark set. Directional and not-comparable rows remain visible, but they never receive a winner in this template.

Agentic

Like-for-like
GPT-5.6 Luna
84.1
GPT-5.6 Sol
92.0
Weighted basis
2 vs 2 rows
Reading
GPT-5.6 Sol leads

Coding

Like-for-like
GPT-5.6 Luna
62.7
GPT-5.6 Sol
64.6
Weighted basis
1 vs 1 rows
Reading
GPT-5.6 Sol leads

Reasoning

Like-for-like
GPT-5.6 Luna
59.5
GPT-5.6 Sol
92.5
Weighted basis
1 vs 1 rows
Reading
GPT-5.6 Sol leads

Knowledge

Like-for-like
GPT-5.6 Luna
92.3
GPT-5.6 Sol
94.6
Weighted basis
1 vs 1 rows
Reading
GPT-5.6 Sol leads

Math

Like-for-like
GPT-5.6 Luna
73.6
GPT-5.6 Sol
87.5
Weighted basis
2 vs 2 rows
Reading
GPT-5.6 Sol leads

Multimodal

Like-for-like
GPT-5.6 Luna
78.4
GPT-5.6 Sol
83.0
Weighted basis
1 vs 1 rows
Reading
GPT-5.6 Sol leads

Multilingual

Not comparable
GPT-5.6 Luna
Not measured
GPT-5.6 Sol
Not measured
Weighted basis
0 vs 0 rows
Reading
Not comparable

Instruction following

Not comparable
GPT-5.6 Luna
Not measured
GPT-5.6 Sol
Not measured
Weighted basis
0 vs 0 rows
Reading
Not comparable

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.

Too few matched category axes support a radar. The ruled list below shows only shared benchmark results; positions use each benchmark’s normalized display scale when available.

  • ARC-AGI-2

    Reasoning

    GPT-5.6 Luna: 59.5%GPT-5.6 Sol: 92.5%Normalized gap 33.0Shared source
  • FrontierMath v2 (Tier 4)

    Math

    GPT-5.6 Luna: 58.500%GPT-5.6 Sol: 83.000%Normalized gap 24.5Shared source
  • FrontierMath v2 (Tiers 1-3)

    Math

    GPT-5.6 Luna: 78.600%GPT-5.6 Sol: 89.000%Normalized gap 10.4Shared source
  • BrowseComp

    Agentic

    GPT-5.6 Luna: 83.3%GPT-5.6 Sol: 92.2%Normalized gap 8.9Shared source
  • Terminal-Bench 2.0

    Agentic

    GPT-5.6 Luna: 84.7%GPT-5.6 Sol: 91.9%Normalized gap 7.2Shared source

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-5.6 Luna
$0.0008
Fits in one request
GPT-5.6 Sol
$0.02
Fits in one request

GPT-5.6 Luna has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

GPT-5.6 Luna
$0.0136
Fits in one request
GPT-5.6 Sol
$0.34
Fits in one request

GPT-5.6 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-5.6 Luna
$0.02
Fits in one request
GPT-5.6 Sol
$0.5
Fits in one request

GPT-5.6 Luna has the lower modeled cost

Costs use the listed standard API rates.

Specification differences

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

Cached-input rate

A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.

GPT-5.6 Luna

$0.02 per 1M cached input tokens

OpenAI pricing

GPT-5.6 Sol

$0.5 per 1M cached input tokens

OpenAI pricing

Reasoning profile

GPT-5.6 Luna

Reasoning

GPT-5.6 Sol

Reasoning

Weight access

GPT-5.6 Luna

Proprietary

GPT-5.6 Sol

Proprietary

License

GPT-5.6 Luna

Proprietary

GPT-5.6 Sol

Proprietary

Release date

GPT-5.6 Luna

2026-07-09

GPT-5.6 Sol

2026-07-09

If you are choosing between sibling variants
Deployment change
Both entries list OpenAI as the provider. Confirm endpoint, model ID, limits, and feature support before switching.
Quality signal
GPT-5.6 Sol has the higher public score, 81.48 versus 66.87, and the 90% score intervals do not overlap.
Workload cost
Repository review: $0.0136 vs $0.34. Cache-heavy agent loop: $0.02 vs $0.5.
Context tradeoff
Both models list 1.05M.

Run the same representative tasks against both endpoints before changing production traffic.

Benchmark evidence

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

Browse raw public benchmark evidence24 rows

Agentic

  • Terminal-Bench 2.0

    Shared source
    GPT-5.6 Luna84.7%
    GPT-5.6 Sol91.9%

    GPT-5.6 Sol leads this result

  • BrowseComp

    Shared source
    GPT-5.6 Luna83.3%
    GPT-5.6 Sol92.2%

    GPT-5.6 Sol leads this result

  • OSWorld 2.0

    Shared source
    GPT-5.6 Luna45.6%
    GPT-5.6 Sol62.6%

    GPT-5.6 Sol leads this result

  • GPT-5.6 Luna77.9%
    GPT-5.6 Sol84.5%

    GPT-5.6 Sol leads this result

  • ExploitGym

    Shared source
    GPT-5.6 Luna12.4%
    GPT-5.6 Sol33.7%

    GPT-5.6 Sol leads this result

  • Toolathlon

    Shared source
    GPT-5.6 Luna53.4%
    GPT-5.6 Sol58%

    GPT-5.6 Sol leads this result

Coding

  • SWE-bench Pro

    Shared source
    GPT-5.6 Luna62.7%
    GPT-5.6 Sol64.6%

    GPT-5.6 Sol leads this result

  • Terminal-Bench 2.0

    Shared source
    GPT-5.6 Luna84.7%
    GPT-5.6 Sol91.9%

    GPT-5.6 Sol leads this result

  • GPT-5.6 Luna67.2%
    GPT-5.6 Sol72.7%

    GPT-5.6 Sol leads this result

  • FrontierCode 1.1 Extended

    Shared source
    GPT-5.6 Luna55.1%
    GPT-5.6 Sol60.6%

    GPT-5.6 Sol leads this result

  • cursorBench32

    Shared source
    GPT-5.6 Luna61.1%
    GPT-5.6 Sol67.2%

    GPT-5.6 Sol leads this result

  • VulcanBench v3

    GPT-5.6 Luna
    GPT-5.6 Sol87.0%
    Source

    Not directly comparable

Reasoning

  • GPT-5.6 Luna59.5%
    GPT-5.6 Sol92.5%

    GPT-5.6 Sol leads this result

  • GPT-5.6 Luna0.2%
    GPT-5.6 Sol7.8%

    GPT-5.6 Sol leads this result

  • GeneBench-Pro

    GPT-5.6 Luna
    GPT-5.6 Sol28.7%
    Source

    Not directly comparable

Knowledge

  • GPT-5.6 Luna92.3%
    GPT-5.6 Sol94.6%

    GPT-5.6 Sol leads this result

  • GPT-5.6 Luna92.3%
    GPT-5.6 Sol94.6%

    GPT-5.6 Sol leads this result

  • HealthBench Professional

    Shared source
    GPT-5.6 Luna55.7%
    GPT-5.6 Sol60.5%

    GPT-5.6 Sol leads this result

  • HealthBench Hard

    Shared source
    GPT-5.6 Luna32.0%
    GPT-5.6 Sol33.1%

    GPT-5.6 Sol leads this result

Math

  • FrontierMath (legacy)

    Shared source
    GPT-5.6 Luna78.6%
    GPT-5.6 Sol89%

    GPT-5.6 Sol leads this result

  • FrontierMath v2 (Tiers 1-3)

    Shared source
    GPT-5.6 Luna78.600%
    GPT-5.6 Sol89.000%

    GPT-5.6 Sol leads this result

  • FrontierMath v2 (Tier 4)

    Shared source
    GPT-5.6 Luna58.500%
    GPT-5.6 Sol83.000%

    GPT-5.6 Sol leads this result

Multimodal

  • GPT-5.6 Luna78.4%
    GPT-5.6 Sol83%

    GPT-5.6 Sol leads this result

  • MMMU-Pro w/ Python

    Shared source
    GPT-5.6 Luna79.5%
    GPT-5.6 Sol84.6%

    GPT-5.6 Sol leads this result

Frequently asked questions

Which is better, GPT-5.6 Luna or GPT-5.6 Sol?

GPT-5.6 Sol has the higher public score, 81.48 versus 66.87, and the 90% score intervals do not overlap. That is the clearest overall quality signal in the current public data.

Which is better for coding, GPT-5.6 Luna or GPT-5.6 Sol?

GPT-5.6 Sol leads the like-for-like coding comparison across 1 shared weighted benchmark row.

Which is better for agentic tasks, GPT-5.6 Luna or GPT-5.6 Sol?

GPT-5.6 Sol leads the like-for-like agentic tasks comparison across 2 shared weighted benchmark rows.

Which costs less, GPT-5.6 Luna or GPT-5.6 Sol?

For the stated presets, chat costs $0.0008 on GPT-5.6 Luna and $0.02 on GPT-5.6 Sol; repository review costs $0.0136 and $0.34; the cache-heavy agent loop costs $0.02 and $0.5. Costs use the listed standard API rates.

Which has the larger context window, GPT-5.6 Luna or GPT-5.6 Sol?

Both models list the same context window, 1.05M.

Related comparisons

Last updated August 10, 2026

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