Model comparison

Claude Sonnet 5 vs GPT-5.6 Terra

GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 54.6 on the Noometry Index.

Last verified . 46 shared benchmarks.

Claude Sonnet 5 Anthropic

54.6

Rank #29 Confirmed

GPT-5.6 Terra OpenAI

59.2

Rank #17 Confirmed

Summary

  • They share 46 benchmarks with published results for both. Claude Sonnet 5 scores higher in 2 categories and GPT-5.6 Terra in 8 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Terra leads 81.6 to 66.2.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 29.3% for Claude Sonnet 5 and 70.7% for GPT-5.6 Terra.
  • Claude Sonnet 5 is cheaper at $2 / $10 per million input/output tokens, against $2 / $12 for GPT-5.6 Terra.
  • GPT-5.6 Terra accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Sonnet 5 and GPT-5.6 Terra specifications
Claude Sonnet 5GPT-5.6 Terra
ProviderAnthropicOpenAI
Noometry Index54.659.2
Released2026-06-292026-07-09
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$2$2
Output $ / M tokens$10$12
Results tracked5152

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Category by category

Coding GPT-5.6 Terra leads

Claude Sonnet 5: 55.5 (#26), GPT-5.6 Terra: 57.7 (#19)

Coding benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
DeepSWE53.8%69.6%
FrontierCode42.7%41.3%
CursorBench34.1%41.3%
LMArena WebDev15411522
SciCode54.3%55%
WeirdML68.8%78.3%
LMArena Coding14831484
ALE-Bench1,4631,951
GSO37.3%—

Agentic & Tool Use Claude Sonnet 5 leads

Claude Sonnet 5: 42.8 (#18), GPT-5.6 Terra: 40.1 (#25)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
APEX-Agents54.5%58.2%
Vending-Bench 26,3787,343
BALROG—53.2%
GBAEval65.3%—
GDP.pdf—24.7%
LMArena Search1194—

Reasoning GPT-5.6 Terra leads

Claude Sonnet 5: 49.1 (#39), GPT-5.6 Terra: 60.7 (#21)

Reasoning benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
SimpleBench60.6%48.9%
NYT Connections (extended)75.1%78.4%
CritPt16.9%30%
Chess Puzzles35%54%
LMArena Hard Prompts14611468
Mystery Game Puzzles35%35%
DTBench92.5%93.3%
LMCA50%55%
Surface Evolver Bench60%83.8%
Epoch Capabilities Index156.21159.62
ARC-AGI-2—83.9%
Kagi LLM Benchmark—51.3%
ARC-AGI-1—96.5%
Bench to the Future 30.14—
ForecastBench61.1—

Math GPT-5.6 Terra leads

Claude Sonnet 5: 66.2 (#27), GPT-5.6 Terra: 81.6 (#12)

Math benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
FrontierMath (Tiers 1-3)65.6%86%
FrontierMath Tier 429.3%70.7%
OTIS Mock AIME 2024-202594.7%99.7%
ProofBench77%74%
LMArena Math14671466

Knowledge GPT-5.6 Terra leads

Claude Sonnet 5: 55.6 (#47), GPT-5.6 Terra: 61.2 (#30)

Knowledge benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
GPQA Diamond90.5%93.3%
SimpleQA Verified33.7%43.2%
LMArena Expert14901492

Multimodal GPT-5.6 Terra leads

Claude Sonnet 5: 42.4 (#31), GPT-5.6 Terra: 47.3 (#11)

Multimodal benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
LMArena Vision12741271
Blueprint-Bench 224.9%30.8%
LMArena Document14661472
Furniture Assembly—54.2%

Multilingual Too close to call

Claude Sonnet 5: 53.8 (#55), GPT-5.6 Terra: 54.4 (#44)

Multilingual benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
LMArena Non-English14311439
LMArena Chinese14771513
LMArena French14601471
LMArena German14401460
LMArena Japanese14221457
LMArena Korean14111425
LMArena Russian14511450
LMArena Spanish14371448

Instruction Following Too close to call

Claude Sonnet 5: 76.3 (#41), GPT-5.6 Terra: 76.4 (#40)

Instruction Following benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
LMArena Instruction Following14521454

Long Context Too close to call

Claude Sonnet 5: 44.8 (#55), GPT-5.6 Terra: 44.4 (#68)

Long Context benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
LMArena Longer Query14631451

Writing & Preference Too close to call

Claude Sonnet 5: 69.2 (#25), GPT-5.6 Terra: 70.2 (#23)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 5GPT-5.6 Terra
LMArena Text14421447
LMArena Creative Writing14161410
EQ-Bench Creative Writing17941855
EQ-Bench 412361234
LMArena Multi-Turn14541449

Frequently asked questions

Is Claude Sonnet 5 better than GPT-5.6 Terra?

GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 54.6 on the Noometry Index.

Which is cheaper, Claude Sonnet 5 or GPT-5.6 Terra?

Claude Sonnet 5 is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; GPT-5.6 Terra lists at $2 and $12.

Is Claude Sonnet 5 or GPT-5.6 Terra better for coding?

GPT-5.6 Terra scores higher on coding benchmarks: 57.7 versus 55.5 in the Noometry coding category.

Which has the bigger context window?

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

How many benchmarks do Claude Sonnet 5 and GPT-5.6 Terra share?

46 benchmarks have published results for both models. Claude Sonnet 5 has 51 scored results on Noometry and GPT-5.6 Terra has 52.

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