Model comparison

GPT-5.6 Terra vs o3-mini

GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 36.7 on the Noometry Index. o3-mini costs 2.3× less per token, which makes it the better buy when GPT-5.6 Terra's lead doesn't matter for your workload.

Last verified . 33 shared benchmarks.

GPT-5.6 Terra OpenAI

59.2

Rank #17 Confirmed

o3-mini OpenAI

36.7

Rank #212 Confirmed

Summary

  • They share 33 benchmarks with published results for both. GPT-5.6 Terra scores higher in 9 categories and o3-mini in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Terra leads 81.6 to 28.1.
  • The biggest single-benchmark swing is ARC-AGI-2: 83.9% for GPT-5.6 Terra and 3% for o3-mini.
  • o3-mini is cheaper at $1.10 / $4.40 per million input/output tokens, against $2 / $12 for GPT-5.6 Terra.
  • GPT-5.6 Terra accepts more context: 1.05M tokens versus 200K.

Side by side

GPT-5.6 Terra and o3-mini specifications
GPT-5.6 Terrao3-mini
ProviderOpenAIOpenAI
Noometry Index59.236.7
Released2026-07-092024-12-20
WeightsProprietaryProprietary
Context window1.05M200K
Max output128K100K
Input $ / M tokens$2$1.10
Output $ / M tokens$12$4.40
Results tracked5251

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Category by category

Coding GPT-5.6 Terra leads

GPT-5.6 Terra: 57.7 (#19), o3-mini: 40.8 (#132)

Coding benchmarks
BenchmarkGPT-5.6 Terrao3-mini
SciCode55%39.8%
WeirdML78.3%43.7%
LMArena Coding14841378
DeepSWE69.6%—
FrontierCode41.3%—
Aider Polyglot—60.4%
CursorBench41.3%—
LMArena WebDev1522—
GSO—1.3%
LiveBench Coding—82.7%
CadEval—54%
ALE-Bench1,951—

Agentic & Tool Use GPT-5.6 Terra leads

GPT-5.6 Terra: 40.1 (#25), o3-mini: 29.6 (#84)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.6 Terrao3-mini
APEX-Agents58.2%—
Cybench—22.5%
BALROG53.2%—
GDP.pdf24.7%—
Vending-Bench 27,343—

Reasoning GPT-5.6 Terra leads

GPT-5.6 Terra: 60.7 (#21), o3-mini: 16.3 (#305)

Reasoning benchmarks
BenchmarkGPT-5.6 Terrao3-mini
ARC-AGI-283.9%3%
SimpleBench48.9%22.8%
ARC-AGI-196.5%34.5%
CritPt30%0.3%
Chess Puzzles54%17%
LMArena Hard Prompts14681366
Mystery Game Puzzles35%7%
DTBench93.3%68.8%
LMCA55%19%
Epoch Capabilities Index159.62140.34
Kagi LLM Benchmark51.3%—
NYT Connections (extended)78.4%—
LiveBench Reasoning—89.6%
LiveBench Data Analysis—70.6%
Surface Evolver Bench83.8%—
ForecastBench—59.6
LiveBench—75.9%

Math GPT-5.6 Terra leads

GPT-5.6 Terra: 81.6 (#12), o3-mini: 28.1 (#244)

Math benchmarks
BenchmarkGPT-5.6 Terrao3-mini
FrontierMath (Tiers 1-3)86%18.6%
FrontierMath Tier 470.7%0%
OTIS Mock AIME 2024-202599.7%76.9%
LMArena Math14661396
ProofBench74%—
LiveBench Math—77.3%
MATH Level 5—96.5%
FrontierMath (Feb 2025 set)—12.4%
FrontierMath Tier 4 (v1)—4.2%

Knowledge GPT-5.6 Terra leads

GPT-5.6 Terra: 61.2 (#30), o3-mini: 38.3 (#146)

Knowledge benchmarks
BenchmarkGPT-5.6 Terrao3-mini
GPQA Diamond93.3%77%
SimpleQA Verified43.2%15.3%
LMArena Expert14921364
Confabulations—17.9%

Multimodal Not comparable

GPT-5.6 Terra: 47.3 (#11), o3-mini: —

Multimodal benchmarks
BenchmarkGPT-5.6 Terrao3-mini
LMArena Vision1271—
Blueprint-Bench 230.8%—
Furniture Assembly54.2%—
LMArena Document1472—

Multilingual GPT-5.6 Terra leads

GPT-5.6 Terra: 54.4 (#44), o3-mini: 45.7 (#164)

Multilingual benchmarks
BenchmarkGPT-5.6 Terrao3-mini
LMArena Non-English14391319
LMArena Chinese15131379
LMArena French14711334
LMArena German14601303
LMArena Japanese14571286
LMArena Korean14251314
LMArena Russian14501304
LMArena Spanish14481321

Instruction Following GPT-5.6 Terra leads

GPT-5.6 Terra: 76.4 (#40), o3-mini: 75.1 (#72)

Instruction Following benchmarks
BenchmarkGPT-5.6 Terrao3-mini
LMArena Instruction Following14541337
LiveBench Instruction Following—84.4%

Long Context GPT-5.6 Terra leads

GPT-5.6 Terra: 44.4 (#68), o3-mini: 33.8 (#256)

Long Context benchmarks
BenchmarkGPT-5.6 Terrao3-mini
LMArena Longer Query14511343
Fiction.LiveBench—50%

Writing & Preference GPT-5.6 Terra leads

GPT-5.6 Terra: 70.2 (#23), o3-mini: 50.3 (#182)

Writing & Preference benchmarks
BenchmarkGPT-5.6 Terrao3-mini
LMArena Text14471337
LMArena Creative Writing14101286
LMArena Multi-Turn14491320
Short-Story Creative Writing—61.7%
EQ-Bench Creative Writing1855—
EQ-Bench 41234—
LiveBench Language—50.7%

Frequently asked questions

Is GPT-5.6 Terra better than o3-mini?

GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 36.7 on the Noometry Index. o3-mini costs 2.3× less per token, which makes it the better buy when GPT-5.6 Terra's lead doesn't matter for your workload.

Which is cheaper, GPT-5.6 Terra or o3-mini?

o3-mini is cheaper. It lists at $1.10 per million input tokens and $4.40 per million output tokens; GPT-5.6 Terra lists at $2 and $12.

Is GPT-5.6 Terra or o3-mini better for coding?

GPT-5.6 Terra scores higher on coding benchmarks: 57.7 versus 40.8 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 GPT-5.6 Terra and o3-mini share?

33 benchmarks have published results for both models. GPT-5.6 Terra has 52 scored results on Noometry and o3-mini has 51.

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