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Model comparison

Claude Fable 5 vs GPT-5.6 Sol

Data verified

Head-to-head evidence from 8 shared benchmark results across 4 categories. Overall scores shown here use BenchLM's provisional ranking lane.

91/100
Margin
5.0pts
← winning
86/100
3 category wins2 category wins

Verified leaderboard positions: Claude Fable 5 #2; GPT-5.6 Sol unranked

Evidence parity. Claude Fable 5 and GPT-5.6 Sol share 8 comparable benchmark results. 5 of 8 categories are comparable. 12 results are unique to Claude Fable 5; 35 to GPT-5.6 Sol.

Updated July 13, 2026
Shared results
8
Claude Fable 5 only
12
GPT-5.6 Sol only
35
Comparable categories
5 / 8

Pick Claude Fable 5 if you want the stronger benchmark profile. GPT-5.6 Sol only becomes the better choice if knowledge is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 8 shared benchmark results across 4 evidence categories; 5 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Fable 5 is clearly ahead on the provisional aggregate, 91 to 86. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Fable 5's sharpest advantage is in coding, where it averages 85.6 against 64.6. The single biggest benchmark swing on the page is SWE-bench Pro, 80% to 64.6%. GPT-5.6 Sol does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

Claude Fable 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $5.00 input / $30.00 output per 1M tokens for GPT-5.6 Sol. Claude Fable 5 gives you the larger context window at 1M+, compared with 1M for GPT-5.6 Sol.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Fable 5 and GPT-5.6 Sol
CategoryClaude Fable 5ΔGPT-5.6 Sol
KnowledgeClaude Fable 568.6Margin 26.0GPT-5.6 Sol94.6
CodingClaude Fable 585.6Margin 21.0GPT-5.6 Sol64.6
MathClaude Fable 597.6Margin 10.1GPT-5.6 Sol87.5
MultimodalClaude Fable 592.9Margin 9.9GPT-5.6 Sol83.0
AgenticClaude Fable 585.3Margin 6.7GPT-5.6 Sol92.0

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Fable 5B · GPT-5.6 Sol
  1. SWE-bench Pro

    Coding
    Source ↗
    A 80%B 64.6%
    Winner: Claude Fable 5Δ 15.4
    SWE-bench Pro: Claude Fable 5 scored 80%; GPT-5.6 Sol scored 64.6%. Claude Fable 5 wins this benchmark.
  2. MMMU-Pro

    Multimodal
    Source ↗
    A 92.7%B 83%
    Winner: Claude Fable 5Δ 9.7
    MMMU-Pro: Claude Fable 5 scored 92.7%; GPT-5.6 Sol scored 83%. Claude Fable 5 wins this benchmark.
  3. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 84.3%B 91.9%
    Winner: GPT-5.6 SolΔ 7.6
    Terminal-Bench 2.0: Claude Fable 5 scored 84.3%; GPT-5.6 Sol scored 91.9%. GPT-5.6 Sol wins this benchmark.
  4. BrowseComp

    Agentic
    Source ↗
    A 86.9%B 92.2%
    Winner: GPT-5.6 SolΔ 5.3
    BrowseComp: Claude Fable 5 scored 86.9%; GPT-5.6 Sol scored 92.2%. GPT-5.6 Sol wins this benchmark.
  5. GPQA

    Knowledge
    Source ↗
    A 94.5%B 94.6%
    Winner: GPT-5.6 SolΔ 0.1
    GPQA: Claude Fable 5 scored 94.5%; GPT-5.6 Sol scored 94.6%. GPT-5.6 Sol wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Fable 5GPT-5.6 SolComparison
Input / output priceUSD per 1M tokensClaude Fable 5$10 input / $50 outputGPT-5.6 Sol$5 input / $30 outputGPT-5.6 Sol has the lower combined listed price.
Generation speedtokens per secondClaude Fable 5Not availableGPT-5.6 SolNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Fable 5Not availableGPT-5.6 SolNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Fable 51M+GPT-5.6 Sol1MListed context windows are equal.

Benchmark Deep Dive

AgenticGPT-5.6 Sol wins
BenchmarkClaude Fable 5GPT-5.6 SolResult
Terminal-Bench 2.0Source 84.3%91.9%GPT-5.6 Sol leads
OSWorld-VerifiedSource 85%Not comparable
BrowseCompSource 86.9%92.2%GPT-5.6 Sol leads
GDPval-AASource 17601748Claude Fable 5 leads
OSWorld 2.0Source 62.6%Not comparable
CyberGymSource 84.5%Not comparable
ExploitGymSource 33.7%Not comparable
ToolathlonSource 58%Not comparable
AA Agentic IndexSource 54.0%Not comparable
Tau2-TelecomSource 85.1%Not comparable
GDPval-AASource 62.4%Not comparable
AA BriefcaseSource 1495Not comparable
AA ITBenchSource 56.2%Not comparable
AA Tau3 BankingSource 33.0%Not comparable
CodingClaude Fable 5 wins
BenchmarkClaude Fable 5GPT-5.6 SolResult
SWE-bench VerifiedSource 95%Not comparable
SWE-bench ProSource 80%64.6%Claude Fable 5 leads
FrontierCodeSource 53.5%Not comparable
Terminal-Bench 2.0Source 84.3%91.9%GPT-5.6 Sol leads
cursorBench31Source 70.6%Not comparable
cursorBench32Source 70.5%67.2%Claude Fable 5 leads
deepSweSource 72.7%Not comparable
FrontierCode 1.1 ExtendedSource 60.6%Not comparable
AA Coding IndexSource 77.4%Not comparable
Terminal-Bench HardSource 65.9%Not comparable
AA-SciCodeSource 56.1%Not comparable
AA Terminal-Bench 2.1Source 88.0%Not comparable
Reasoning
BenchmarkClaude Fable 5GPT-5.6 SolResult
ARC-AGI-3Source 7.8%Not comparable
GeneBench-ProSource 28.7%Not comparable
AA-LCRSource 73.7%Not comparable
CritPtSource 32.3%Not comparable
KnowledgeGPT-5.6 Sol wins
BenchmarkClaude Fable 5GPT-5.6 SolResult
GPQASource 94.5%94.6%GPT-5.6 Sol leads
HLESource 64.5%Not comparable
HLE w/o toolsSource 59%Not comparable
GPQA-DSource 94.6%Not comparable
HealthBench ProfessionalSource 60.5%Not comparable
HealthBench HardSource 33.1%Not comparable
Artificial Analysis Intelligence IndexSource 58.9%Not comparable
AA-GPQA DiamondSource 94.1%Not comparable
AA-HLESource 47.2%Not comparable
AA-Omniscience IndexSource 21.7%Not comparable
AA-Omniscience AccuracySource 58.5%Not comparable
AA-Omniscience Hallucination RateSource 88.8%Not comparable
MathClaude Fable 5 wins
BenchmarkClaude Fable 5GPT-5.6 SolResult
USAMO 2026Source 97.6%Not comparable
FrontierMath (legacy)Source 89%Not comparable
FrontierMath v2 (Tiers 1-3)Source 89.000%Not comparable
FrontierMath v2 (Tier 4)Source 83.000%Not comparable
Multilingual
BenchmarkClaude Fable 5GPT-5.6 SolResult
SWE MultilingualSource 87.3%Not comparable
MultimodalClaude Fable 5 wins
BenchmarkClaude Fable 5GPT-5.6 SolResult
MMMU-ProSource 92.7%83%Claude Fable 5 leads
SWE-bench MultimodalSource 59%Not comparable
CharXivSource 93.2%Not comparable
CharXiv w/o toolsSource 86.1%Not comparable
Blueprint-Bench 2Source 38.6%Not comparable
MMMU-Pro w/ PythonSource 84.6%Not comparable
AA-MMMU-ProSource 83.4%Not comparable
Inst. Following
BenchmarkClaude Fable 5GPT-5.6 SolResult
AA-IFBenchSource 72.7%Not comparable
Frequently Asked Questions (6)

Which is better, Claude Fable 5 or GPT-5.6 Sol?

Claude Fable 5 is ahead on BenchLM's provisional leaderboard, 91 to 86. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 80% and 64.6%.

Which is better for knowledge tasks, Claude Fable 5 or GPT-5.6 Sol?

GPT-5.6 Sol has the edge for knowledge tasks in this comparison, averaging 94.6 versus 68.6. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Fable 5 or GPT-5.6 Sol?

Claude Fable 5 has the edge for coding in this comparison, averaging 85.6 versus 64.6. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, Claude Fable 5 or GPT-5.6 Sol?

Claude Fable 5 has the edge for math in this comparison, averaging 97.6 versus 87.5. GPT-5.6 Sol stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Claude Fable 5 or GPT-5.6 Sol?

GPT-5.6 Sol has the edge for agentic tasks in this comparison, averaging 92 versus 85.3. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Fable 5 or GPT-5.6 Sol?

Claude Fable 5 has the edge for multimodal and grounded tasks in this comparison, averaging 92.9 versus 83. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

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Last updated: July 13, 2026

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