Noometry

Model comparison

Claude Opus 4.8 vs GPT-5.1

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 49.0 on the Noometry Index. GPT-5.1 costs 2.9× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Last verified . 43 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

GPT-5.1 OpenAI

49.0

Rank #53 Confirmed

Summary

  • They share 43 benchmarks with published results for both. Claude Opus 4.8 scores higher in 7 categories and GPT-5.1 in 3 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 4.8 leads 78.4 to 52.2.
  • The biggest single-benchmark swing is ARC-AGI-2: 72.1% for Claude Opus 4.8 and 17.6% for GPT-5.1.
  • GPT-5.1 is cheaper at $1.25 / $10 per million input/output tokens, against $5 / $25 for Claude Opus 4.8.
  • Claude Opus 4.8 accepts more context: 1M tokens versus 400K.

Side by side

Claude Opus 4.8GPT-5.1
ProviderAnthropicOpenAI
Noometry Index60.749.0
Released2026-05-282025-11-13
WeightsProprietaryProprietary
Context window1M400K
Max output128K128K
Input $ / M tokens$5$1.25
Output $ / M tokens$25$10
Results tracked6563

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.8: 59.9 (#12), GPT-5.1: 46.4 (#66)

BenchmarkClaude Opus 4.8GPT-5.1
LMArena WebDev15561395
SciCode53.5%43.3%
GSO47.1%13.7%
WeirdML82.9%60.8%
LMArena Coding14901454
ALE-Bench1,5641,192
SWE-bench Verified—68%
DeepSWE59%—
FrontierCode46.5%—
SWE-bench Verified (bash only)—66%
LiveBench Coding—72.5%

Agentic & Tool Use Claude Opus 4.8 leads

Claude Opus 4.8: 47.6 (#11), GPT-5.1: 32.7 (#60)

BenchmarkClaude Opus 4.8GPT-5.1
DeepResearch Bench50.2%42.8%
LMArena Search12041199
Vending-Bench 25,7871,473
Terminal-Bench—47.6%
APEX-Agents48.9%—
OSWorld 2.020.6%—
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
PostTrainBench33.8%—
GBAEval70.9%—
GDP.pdf24%—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.8: 64.7 (#16), GPT-5.1: 39.8 (#58)

BenchmarkClaude Opus 4.8GPT-5.1
ARC-AGI-272.1%17.6%
SimpleBench64.8%53.2%
ARC-AGI-192.5%72.8%
CritPt20.9%4.9%
Chess Puzzles34%32%
EnigmaEval23.5%11.2%
LMArena Hard Prompts14821457
Mystery Game Puzzles36%19%
DTBench94.9%90.1%
LMCA57.5%43.9%
Epoch Capabilities Index158.21149.64
ForecastBench59.958.1
Kagi LLM Benchmark88.8%—
NYT Connections (extended)91.1%—
EBR-Bench28.6%—
LiveBench Reasoning—95.8%
LiveBench Data Analysis—72.1%
Surface Evolver Bench87.5%—
Bench to the Future 30.14—
LiveBench—78.8%

Math Claude Opus 4.8 leads

Claude Opus 4.8: 78.4 (#13), GPT-5.1: 52.2 (#51)

BenchmarkClaude Opus 4.8GPT-5.1
OTIS Mock AIME 2024-202598.3%88.6%
LMArena Math14871447
FrontierMath (Feb 2025 set)47.2%31%
FrontierMath Tier 4 (v1)31.3%12.5%
FrontierMath (Tiers 1-3)80%—
FrontierMath Tier 456.1%—
MathArena Final-Answer Competitions91.8%—
ProofBench69%—
Omni-MATH—46.4%
LiveBench Math—94.5%

Knowledge Claude Opus 4.8 leads

Claude Opus 4.8: 61.3 (#29), GPT-5.1: 50.6 (#71)

BenchmarkClaude Opus 4.8GPT-5.1
GPQA Diamond91%87.6%
SimpleQA Verified53%48%
LMArena Expert15021470
Humanity's Last Exam—23.7%
MMLU-Pro—57.9%
Vectara Hallucination Rate—10.9%
GPQA (HELM)—44.2%

Multimodal GPT-5.1 leads

Claude Opus 4.8: 42.9 (#26), GPT-5.1: 44.8 (#19)

BenchmarkClaude Opus 4.8GPT-5.1
LMArena Vision12941250
LMArena Document14751403
VPCT—58.7%
Blueprint-Bench 214.5%—
Furniture Assembly42.5%—

Multilingual Claude Opus 4.8 leads

Claude Opus 4.8: 55.2 (#33), GPT-5.1: 53.8 (#56)

BenchmarkClaude Opus 4.8GPT-5.1
LMArena Non-English14501431
LMArena Chinese15071495
LMArena French14811450
LMArena German14721438
LMArena Japanese14401453
LMArena Korean14321401
LMArena Russian14741435
LMArena Spanish14661433

Instruction Following GPT-5.1 leads

Claude Opus 4.8: 77.4 (#24), GPT-5.1: 83.9 (#1)

BenchmarkClaude Opus 4.8GPT-5.1
LMArena Instruction Following14761443
LiveBench Instruction Following—93.3%
IFEval—93.5%

Long Context GPT-5.1 leads

Claude Opus 4.8: 45.4 (#35), GPT-5.1: 47.6 (#14)

BenchmarkClaude Opus 4.8GPT-5.1
LMArena Longer Query14831447
CL-bench—23.7%
CL-bench Life—17.3%

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.8: 72.0 (#16), GPT-5.1: 64.5 (#55)

BenchmarkClaude Opus 4.8GPT-5.1
LMArena Text14611443
LMArena Creative Writing14541427
LMArena Multi-Turn14761450
EQ-Bench Creative Writing1840—
WildBench—86.3%
EQ-Bench 41281—
LiveBench Language—80.2%

Frequently asked questions

Is Claude Opus 4.8 better than GPT-5.1?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 49.0 on the Noometry Index. GPT-5.1 costs 2.9× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.8 or GPT-5.1?

GPT-5.1 is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; Claude Opus 4.8 lists at $5 and $25.

Is Claude Opus 4.8 or GPT-5.1 better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 46.4 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 4.8 does, with 1M tokens against 400K.

How many benchmarks do Claude Opus 4.8 and GPT-5.1 share?

43 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and GPT-5.1 has 63.

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