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Model comparison

Claude Fable 5 vs GPT-5.6 Sol

Data verified

Head-to-head evidence from 26 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.68/100
Margin
1.7pts
← winning
81.96/100
1 category wins2 category wins

Public leaderboard positions: Claude Fable 5 #2 (Supported); GPT-5.6 Sol #3 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Fable 5 and GPT-5.6 Sol share 26 comparable benchmark results. 3 of 8 categories are comparable. 8 results are unique to Claude Fable 5; 20 to GPT-5.6 Sol.

Updated July 23, 2026
Shared results
26
Claude Fable 5 only
8
GPT-5.6 Sol only
20
Comparable categories
3 / 8

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

Confidence note. This is a partial-evidence comparison with 26 shared benchmark results across 5 evidence categories; 3 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 has the cleaner BenchAlign overall profile here, landing at 83.68 versus 81.96. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Claude Fable 5's sharpest advantage is in coding, where it averages 89.2 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 multimodal & grounded, 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
MultimodalClaude Fable 557.9Margin→ 25.1GPT-5.6 Sol83.0
CodingClaude Fable 589.2Margin← 24.6GPT-5.6 Sol64.6
AgenticClaude Fable 584.6Margin→ 7.4GPT-5.6 Sol92.0
KnowledgeClaude Fable 5Not measuredMarginNo overlapGPT-5.6 Sol94.6
MathClaude Fable 5Not measuredMarginNo overlapGPT-5.6 Sol87.5

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. 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.

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 Sol1MClaude Fable 5 lists the larger context window.

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
GDPval-AASource 17481736Claude Fable 5 leads
AA Agentic IndexSource 52.8%54.0%GPT-5.6 Sol leads
τ²-bench resultsSource 98.5%85.1%Claude Fable 5 leads
GDPval-AASource 62.4%61.8%Claude Fable 5 leads
AA BriefcaseSource 15741501Claude Fable 5 leads
AA AutomationBenchSource 48.6%51.2%GPT-5.6 Sol leads
AA EnterpriseOps-GymSource 51.1%—Not comparable
AA Harvey LABSource 93.6%87.2%Claude Fable 5 leads
AA Tau3 BankingSource 26.8%33.0%GPT-5.6 Sol leads
terminalBenchHardSource 62.9%65.9%GPT-5.6 Sol leads
aaTerminalBench21Source 84.6%88%GPT-5.6 Sol leads
BrowseCompSource —92.2%Not comparable
OSWorld 2.0Source —62.6%Not comparable
CyberGymSource —84.5%Not comparable
ExploitGymSource —33.7%Not comparable
ToolathlonSource —58%Not comparable
AA ITBenchSource —56.2%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
FrontierCode 1.1 MainSource 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
VulcanBench v3Source 87.0%87.0%Tie
AA Coding IndexSource 76.5%77.4%GPT-5.6 Sol leads
AA-SciCodeSource 60.2%56.1%Claude Fable 5 leads
deepSweSource —72.7%Not comparable
FrontierCode 1.1 ExtendedSource —60.6%Not comparable
Reasoning
BenchmarkClaude Fable 5GPT-5.6 SolResult
AA-LCRSource 70.0%73.7%GPT-5.6 Sol leads
CritPtSource 28.6%32.3%GPT-5.6 Sol leads
ARC-AGI-3Source —7.8%Not comparable
GeneBench-ProSource —28.7%Not comparable
Knowledge
BenchmarkClaude Fable 5GPT-5.6 SolResult
Artificial Analysis Intelligence IndexSource 59.9%58.9%Claude Fable 5 leads
AA-GPQA DiamondSource 92.6%94.1%GPT-5.6 Sol leads
AA-HLESource 53.3%47.2%Claude Fable 5 leads
AA-Omniscience IndexSource 40.2%21.7%Claude Fable 5 leads
AA-Omniscience AccuracySource 61.4%58.5%Claude Fable 5 leads
AA-Omniscience Hallucination RateSource 54.9%88.8%Claude Fable 5 leads
GPQASource —94.6%Not comparable
GPQA-DSource —94.6%Not comparable
HealthBench ProfessionalSource —60.5%Not comparable
HealthBench HardSource —33.1%Not comparable
Math
BenchmarkClaude Fable 5GPT-5.6 SolResult
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
MultimodalGPT-5.6 Sol wins
BenchmarkClaude Fable 5GPT-5.6 SolResult
Blueprint-Bench 2Source 38.6%—Not comparable
OfficeQA ProSource 57.9%—Not comparable
Design Arena WebsiteSource 1332—Not comparable
MMMU-ProSource —83%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 63.5%72.7%GPT-5.6 Sol leads
Frequently Asked Questions (4)

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

Claude Fable 5 is ahead on BenchLM's BenchAlign leaderboard, 83.68 to 81.96. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 80% and 64.6%.

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 89.2 versus 64.6. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

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 84.6. Inside this category, AA Briefcase 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?

GPT-5.6 Sol has the edge for multimodal and grounded tasks in this comparison, averaging 83 versus 57.9. Claude Fable 5 stays close enough that the answer can still flip depending on your workload.

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