Model comparison

Claude Opus 4.5 vs GPT-5.6 Terra

GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 50.5 on the Noometry Index.

Last verified . 41 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

GPT-5.6 Terra OpenAI

59.2

Rank #17 Confirmed

Summary

  • They share 41 benchmarks with published results for both. Claude Opus 4.5 scores higher in 3 categories and GPT-5.6 Terra in 7 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Terra leads 81.6 to 38.6.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 4.9% for Claude Opus 4.5 and 70.7% for GPT-5.6 Terra.
  • GPT-5.6 Terra is cheaper at $2 / $12 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
  • GPT-5.6 Terra accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Opus 4.5 and GPT-5.6 Terra specifications
Claude Opus 4.5GPT-5.6 Terra
ProviderAnthropicOpenAI
Noometry Index50.559.2
Released2025-11-012026-07-09
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K128K
Input $ / M tokens$5$2
Output $ / M tokens$25$12
Results tracked6952

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Category by category

Coding GPT-5.6 Terra leads

Claude Opus 4.5: 54.8 (#27), GPT-5.6 Terra: 57.7 (#19)

Coding benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
LMArena WebDev14941522
WeirdML63.7%78.3%
LMArena Coding15041484
ALE-Bench1,0251,951
SWE-bench Verified76.7%—
DeepSWE—69.6%
FrontierCode—41.3%
SWE-bench Verified (bash only)76.8%—
CursorBench—41.3%
SWE-bench Multilingual70.7%—
SciCode—55%
GSO26.5%—
AlgoTune1.77—

Agentic & Tool Use Claude Opus 4.5 leads

Claude Opus 4.5: 47.3 (#12), GPT-5.6 Terra: 40.1 (#25)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
BALROG43.5%53.2%
Vending-Bench 24,9677,343
Terminal-Bench63.1%—
APEX-Agents—58.2%
Berkeley Function Calling Leaderboard77.5%—
GDPval45.5%—
Remote Labor Index3.8%—
τ²-bench Airline84%—
τ²-bench Banking24.7%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
Cybench82%—
DeepResearch Bench54.8%—
OSWorld66.3%—
GDP.pdf—24.7%
LMArena Search1180—
METR Time Horizons75%—

Reasoning GPT-5.6 Terra leads

Claude Opus 4.5: 42.6 (#51), GPT-5.6 Terra: 60.7 (#21)

Reasoning benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
ARC-AGI-237.6%83.9%
SimpleBench62%48.9%
Kagi LLM Benchmark80.2%51.3%
NYT Connections (extended)52.5%78.4%
ARC-AGI-180%96.5%
Chess Puzzles12%54%
LMArena Hard Prompts14761468
Mystery Game Puzzles22%35%
DTBench89.9%93.3%
LMCA44.5%55%
Epoch Capabilities Index150.09159.62
CritPt—30%
EnigmaEval11.9%—
EBR-Bench14.3%—
Surface Evolver Bench—83.8%
ForecastBench60.7—

Math GPT-5.6 Terra leads

Claude Opus 4.5: 38.6 (#132), GPT-5.6 Terra: 81.6 (#12)

Math benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
FrontierMath (Tiers 1-3)34.4%86%
FrontierMath Tier 44.9%70.7%
OTIS Mock AIME 2024-202586.1%99.7%
ProofBench36%74%
LMArena Math14631466
FrontierMath (Feb 2025 set)20.7%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge GPT-5.6 Terra leads

Claude Opus 4.5: 56.5 (#44), GPT-5.6 Terra: 61.2 (#30)

Knowledge benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
GPQA Diamond86%93.3%
SimpleQA Verified45.7%43.2%
LMArena Expert14871492
Humanity's Last Exam25.2%—
Vectara Hallucination Rate10.9%—

Multimodal GPT-5.6 Terra leads

Claude Opus 4.5: 31.4 (#107), GPT-5.6 Terra: 47.3 (#11)

Multimodal benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
Furniture Assembly28.3%54.2%
LMArena Document14621472
LMArena Vision—1271
GeoBench75%—
VPCT40%—
Blueprint-Bench 2—30.8%

Multilingual Too close to call

Claude Opus 4.5: 54.3 (#47), GPT-5.6 Terra: 54.4 (#44)

Multilingual benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
LMArena Non-English14381439
LMArena Chinese14701513
LMArena French14711471
LMArena German14491460
LMArena Japanese14161457
LMArena Korean14241425
LMArena Russian14471450
LMArena Spanish14581448

Instruction Following Claude Opus 4.5 leads

Claude Opus 4.5: 77.5 (#19), GPT-5.6 Terra: 76.4 (#40)

Instruction Following benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
LMArena Instruction Following14781454

Long Context Claude Opus 4.5 leads

Claude Opus 4.5: 46.5 (#22), GPT-5.6 Terra: 44.4 (#68)

Long Context benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
LMArena Longer Query14801451
CL-bench21.1%—

Writing & Preference GPT-5.6 Terra leads

Claude Opus 4.5: 68.1 (#28), GPT-5.6 Terra: 70.2 (#23)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.5GPT-5.6 Terra
LMArena Text14511447
LMArena Creative Writing14451410
EQ-Bench Creative Writing16871855
LMArena Multi-Turn14661449
EQ-Bench 4—1234

Frequently asked questions

Is Claude Opus 4.5 better than GPT-5.6 Terra?

GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 50.5 on the Noometry Index.

Which is cheaper, Claude Opus 4.5 or GPT-5.6 Terra?

GPT-5.6 Terra is cheaper. It lists at $2 per million input tokens and $12 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or GPT-5.6 Terra better for coding?

GPT-5.6 Terra scores higher on coding benchmarks: 57.7 versus 54.8 in the Noometry coding category.

Which has the bigger context window?

GPT-5.6 Terra does, with 1.05M tokens against 200K.

How many benchmarks do Claude Opus 4.5 and GPT-5.6 Terra share?

41 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and GPT-5.6 Terra has 52.

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