Model comparison

Claude Sonnet 5 vs GPT-6 Astra

GPT-6 Astra is the stronger model overall, scoring 70.3 to 54.5 on the Noometry Index. Claude Sonnet 5 costs 5.0× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

Last verified . 40 shared benchmarks.

Claude Sonnet 5 Anthropic

54.5

Rank #26 Confirmed

GPT-6 Astra OpenAI

70.3

Rank #1 Confirmed

Summary

  • They share 40 benchmarks with published results for both. Claude Sonnet 5 scores higher in 1 category and GPT-6 Astra in 9 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-6 Astra leads 85.1 to 48.2.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 29.3% for Claude Sonnet 5 and 97.6% for GPT-6 Astra.
  • Claude Sonnet 5 is cheaper at $2 / $10 per million input/output tokens, against $10 / $50 for GPT-6 Astra.
  • GPT-6 Astra accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Sonnet 5 and GPT-6 Astra specifications
Claude Sonnet 5GPT-6 Astra
ProviderAnthropicOpenAI
Noometry Index54.570.3
Released2026-06-292026-09-03
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$2$10
Output $ / M tokens$10$50
Results tracked5151

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Category by category

Coding GPT-6 Astra leads

Claude Sonnet 5: 55.5 (#20), GPT-6 Astra: 70.5 (#3)

Coding benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
DeepSWE53.8%74.1%
FrontierCode42.7%53.3%
LMArena WebDev15401792
SciCode53.6%56.5%
WeirdML68.8%93.6%
LMArena Coding14831488
ALE-Bench1,4632,951
CursorBench34.1%—
FrontierSWE—65.5%
GSO37.3%—
MirrorCode—46.7%

Agentic & Tool Use GPT-6 Astra leads

Claude Sonnet 5: 42.7 (#16), GPT-6 Astra: 52.3 (#3)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
APEX-Agents54.5%64.7%
Vending-Bench 26,37815,515
Remote Labor Index—20.8%
BALROG—68.3%
GBAEval65.3%—
LMArena Search1194—

Reasoning GPT-6 Astra leads

Claude Sonnet 5: 48.2 (#37), GPT-6 Astra: 85.1 (#1)

Reasoning benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
NYT Connections (extended)75.1%98.1%
CritPt16.9%31.7%
Chess Puzzles35%72%
LMArena Hard Prompts14611464
Mystery Game Puzzles35%84%
DTBench92.5%97.3%
LMCA50%64.4%
Bench to the Future 30.140.14
Epoch Capabilities Index156.34166.6
ARC-AGI-2—95%
SimpleBench60.6%—
ARC-AGI-1—98.5%
EBR-Bench—76.2%
Surface Evolver Bench60%—
ForecastBench61.1—

Math GPT-6 Astra leads

Claude Sonnet 5: 66.1 (#21), GPT-6 Astra: 93.4 (#1)

Math benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
FrontierMath (Tiers 1-3)65.6%93.7%
FrontierMath Tier 429.3%97.6%
OTIS Mock AIME 2024-202594.7%100%
ProofBench77%99%
LMArena Math14671463
FrontierMath Erdős—2.9%

Knowledge GPT-6 Astra leads

Claude Sonnet 5: 55.7 (#42), GPT-6 Astra: 75.3 (#1)

Knowledge benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
GPQA Diamond90.5%95.8%
SimpleQA Verified33.7%75.6%
LMArena Expert14911486
Humanity's Last Exam—54.8%
Vectara Hallucination Rate—8.7%

Multimodal GPT-6 Astra leads

Claude Sonnet 5: 42.4 (#26), GPT-6 Astra: 55.1 (#3)

Multimodal benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
LMArena Vision12751280
Blueprint-Bench 224.9%49.7%
LMArena Document14661468
Furniture Assembly—80%

Multilingual Too close to call

Claude Sonnet 5: 54.0 (#55), GPT-6 Astra: 54.0 (#53)

Multilingual benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
LMArena Non-English14311431
LMArena Chinese14751495
LMArena French14571467
LMArena Russian14521434
LMArena Spanish14361412
LMArena German1448—
LMArena Japanese1422—
LMArena Korean1411—

Instruction Following Too close to call

Claude Sonnet 5: 76.6 (#39), GPT-6 Astra: 76.6 (#37)

Instruction Following benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
LMArena Instruction Following14531454

Long Context Too close to call

Claude Sonnet 5: 44.8 (#53), GPT-6 Astra: 44.7 (#57)

Long Context benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
LMArena Longer Query14641460

Writing & Preference GPT-6 Astra leads

Claude Sonnet 5: 69.4 (#24), GPT-6 Astra: 75.7 (#7)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 5GPT-6 Astra
LMArena Text14431443
LMArena Creative Writing14161423
EQ-Bench Creative Writing17942173
LMArena Multi-Turn14541457
EQ-Bench 41236—

Frequently asked questions

Is Claude Sonnet 5 better than GPT-6 Astra?

GPT-6 Astra is the stronger model overall, scoring 70.3 to 54.5 on the Noometry Index. Claude Sonnet 5 costs 5.0× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 5 or GPT-6 Astra?

Claude Sonnet 5 is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; GPT-6 Astra lists at $10 and $50.

Is Claude Sonnet 5 or GPT-6 Astra better for coding?

GPT-6 Astra scores higher on coding benchmarks: 70.5 versus 55.5 in the Noometry coding category.

Which has the bigger context window?

GPT-6 Astra does, with 1.05M tokens against 1M.

How many benchmarks do Claude Sonnet 5 and GPT-6 Astra share?

40 benchmarks have published results for both models. Claude Sonnet 5 has 51 scored results on Noometry and GPT-6 Astra has 51.

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