Model comparison

Claude Opus 4.8 vs GPT-5.6 Sol

GPT-5.6 Sol is the stronger model overall, scoring 65.0 to 60.7 on the Noometry Index.

Last verified . 59 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

GPT-5.6 Sol OpenAI

65.0

Rank #7 Confirmed

Summary

  • They share 59 benchmarks with published results for both. Claude Opus 4.8 scores higher in 1 category and GPT-5.6 Sol in 9 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.6 Sol leads 74.8 to 64.7.
  • The biggest single-benchmark swing is Chess Puzzles: 34% for Claude Opus 4.8 and 64% for GPT-5.6 Sol.
  • GPT-5.6 Sol is cheaper at $4 / $20 per million input/output tokens, against $5 / $25 for Claude Opus 4.8.
  • GPT-5.6 Sol accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Opus 4.8 and GPT-5.6 Sol specifications
Claude Opus 4.8GPT-5.6 Sol
ProviderAnthropicOpenAI
Noometry Index60.765.0
Released2026-05-282026-07-09
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$5$4
Output $ / M tokens$25$20
Results tracked6565

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Category by category

Coding GPT-5.6 Sol leads

Claude Opus 4.8: 59.9 (#12), GPT-5.6 Sol: 65.1 (#7)

Coding benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
DeepSWE59%72.7%
FrontierCode46.5%47.5%
LMArena WebDev15561618
SciCode53.5%57.1%
GSO47.1%76.5%
WeirdML82.9%89.4%
LMArena Coding14901498
ALE-Bench1,5642,177
CursorBench—41.7%
FrontierSWE—32.2%
MirrorCode—20%

Agentic & Tool Use GPT-5.6 Sol leads

Claude Opus 4.8: 47.6 (#11), GPT-5.6 Sol: 50.3 (#7)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
APEX-Agents48.9%51.4%
OSWorld 2.020.6%27.3%
τ²-bench Banking39.7%46.9%
PostTrainBench33.8%36.2%
GBAEval70.9%52.6%
GDP.pdf24%30.7%
LMArena Search12041257
Vending-Bench 25,7879,619
Remote Labor Index8.3%—
DeepResearch Bench50.2%—
BALROG—60%

Reasoning GPT-5.6 Sol leads

Claude Opus 4.8: 64.7 (#16), GPT-5.6 Sol: 74.8 (#8)

Reasoning benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
ARC-AGI-272.1%92.5%
SimpleBench64.8%71.7%
Kagi LLM Benchmark88.8%67%
NYT Connections (extended)91.1%93.8%
ARC-AGI-192.5%97.5%
CritPt20.9%32.3%
Chess Puzzles34%64%
EnigmaEval23.5%37.1%
EBR-Bench28.6%44.8%
LMArena Hard Prompts14821484
Mystery Game Puzzles36%58%
DTBench94.9%96%
LMCA57.5%59.2%
Surface Evolver Bench87.5%93.1%
Bench to the Future 30.140.14
Epoch Capabilities Index158.21161.66
ForecastBench59.9—

Math GPT-5.6 Sol leads

Claude Opus 4.8: 78.4 (#13), GPT-5.6 Sol: 85.6 (#9)

Knowledge GPT-5.6 Sol leads

Claude Opus 4.8: 61.3 (#29), GPT-5.6 Sol: 64.3 (#18)

Knowledge benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
GPQA Diamond91%93.5%
SimpleQA Verified53%69.7%
LMArena Expert15021516
Vectara Hallucination Rate—12.4%

Multimodal GPT-5.6 Sol leads

Claude Opus 4.8: 42.9 (#26), GPT-5.6 Sol: 48.6 (#9)

Multimodal benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
LMArena Vision12941281
Blueprint-Bench 214.5%33.6%
Furniture Assembly42.5%56.7%
LMArena Document14751483

Multilingual Too close to call

Claude Opus 4.8: 55.2 (#33), GPT-5.6 Sol: 55.3 (#32)

Multilingual benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
LMArena Non-English14501452
LMArena Chinese15071527
LMArena French14811477
LMArena German14721476
LMArena Japanese14401471
LMArena Korean14321442
LMArena Russian14741468
LMArena Spanish14661441

Instruction Following Too close to call

Claude Opus 4.8: 77.4 (#24), GPT-5.6 Sol: 77.7 (#16)

Instruction Following benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
LMArena Instruction Following14761482

Long Context Too close to call

Claude Opus 4.8: 45.4 (#35), GPT-5.6 Sol: 45.4 (#42)

Long Context benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
LMArena Longer Query14831480

Writing & Preference GPT-5.6 Sol leads

Claude Opus 4.8: 72.0 (#16), GPT-5.6 Sol: 73.3 (#12)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.8GPT-5.6 Sol
LMArena Text14611457
LMArena Creative Writing14541448
EQ-Bench Creative Writing18401972
EQ-Bench 412811250
LMArena Multi-Turn14761460

Frequently asked questions

Is Claude Opus 4.8 better than GPT-5.6 Sol?

GPT-5.6 Sol is the stronger model overall, scoring 65.0 to 60.7 on the Noometry Index.

Which is cheaper, Claude Opus 4.8 or GPT-5.6 Sol?

GPT-5.6 Sol is cheaper. It lists at $4 per million input tokens and $20 per million output tokens; Claude Opus 4.8 lists at $5 and $25.

Is Claude Opus 4.8 or GPT-5.6 Sol better for coding?

GPT-5.6 Sol scores higher on coding benchmarks: 65.1 versus 59.9 in the Noometry coding category.

Which has the bigger context window?

GPT-5.6 Sol does, with 1.05M tokens against 1M.

How many benchmarks do Claude Opus 4.8 and GPT-5.6 Sol share?

59 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and GPT-5.6 Sol has 65.

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