Model comparison

Aion 3.5 vs GPT-5.6 Terra

GPT-5.6 Terra has enough public results to be ranked (#17); Aion 3.5 does not yet, so treat this comparison as directional.

Last verified . 1 shared benchmarks.

Aion 3.5 AionLabs

58.1

Unranked Sparse

GPT-5.6 Terra OpenAI

59.2

Rank #17 Confirmed

Summary

  • They share 1 benchmark with published results for both. Aion 3.5 scores higher in 1 category and GPT-5.6 Terra in 0 categories; one gap is clear of the uncertainty.
  • The widest gap is in writing & preference, where Aion 3.5 leads 74.9 to 70.2.
  • Aion 3.5 is cheaper at $3 / $6 per million input/output tokens, against $2 / $12 for GPT-5.6 Terra.
  • GPT-5.6 Terra accepts more context: 1.05M tokens versus 262K.

Side by side

Aion 3.5 and GPT-5.6 Terra specifications
Aion 3.5GPT-5.6 Terra
ProviderAionLabsOpenAI
Noometry Index58.159.2
Released—2026-07-09
WeightsProprietaryProprietary
Context window262K1.05M
Max output33K128K
Input $ / M tokens$3$2
Output $ / M tokens$6$12
Results tracked152

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Category by category

Coding Not comparable

Aion 3.5: —, GPT-5.6 Terra: 57.7 (#19)

Coding benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
DeepSWE—69.6%
FrontierCode—41.3%
CursorBench—41.3%
LMArena WebDev—1522
SciCode—55%
WeirdML—78.3%
LMArena Coding—1484
ALE-Bench—1,951

Agentic & Tool Use Not comparable

Aion 3.5: —, GPT-5.6 Terra: 40.1 (#25)

Agentic & Tool Use benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
APEX-Agents—58.2%
BALROG—53.2%
GDP.pdf—24.7%
Vending-Bench 2—7,343

Reasoning Not comparable

Aion 3.5: —, GPT-5.6 Terra: 60.7 (#21)

Reasoning benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
ARC-AGI-2—83.9%
SimpleBench—48.9%
Kagi LLM Benchmark—51.3%
NYT Connections (extended)—78.4%
ARC-AGI-1—96.5%
CritPt—30%
Chess Puzzles—54%
LMArena Hard Prompts—1468
Mystery Game Puzzles—35%
DTBench—93.3%
LMCA—55%
Surface Evolver Bench—83.8%
Epoch Capabilities Index—159.62

Math Not comparable

Aion 3.5: —, GPT-5.6 Terra: 81.6 (#12)

Math benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
FrontierMath (Tiers 1-3)—86%
FrontierMath Tier 4—70.7%
OTIS Mock AIME 2024-2025—99.7%
ProofBench—74%
LMArena Math—1466

Knowledge Not comparable

Aion 3.5: —, GPT-5.6 Terra: 61.2 (#30)

Knowledge benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
GPQA Diamond—93.3%
SimpleQA Verified—43.2%
LMArena Expert—1492

Multimodal Not comparable

Aion 3.5: —, GPT-5.6 Terra: 47.3 (#11)

Multimodal benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
LMArena Vision—1271
Blueprint-Bench 2—30.8%
Furniture Assembly—54.2%
LMArena Document—1472

Multilingual Not comparable

Aion 3.5: —, GPT-5.6 Terra: 54.4 (#44)

Multilingual benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
LMArena Non-English—1439
LMArena Chinese—1513
LMArena French—1471
LMArena German—1460
LMArena Japanese—1457
LMArena Korean—1425
LMArena Russian—1450
LMArena Spanish—1448

Instruction Following Not comparable

Aion 3.5: —, GPT-5.6 Terra: 76.4 (#40)

Instruction Following benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
LMArena Instruction Following—1454

Long Context Not comparable

Aion 3.5: —, GPT-5.6 Terra: 44.4 (#68)

Long Context benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
LMArena Longer Query—1451

Writing & Preference Aion 3.5 leads

Aion 3.5: 74.9, GPT-5.6 Terra: 70.2 (#23)

Writing & Preference benchmarks
BenchmarkAion 3.5GPT-5.6 Terra
EQ-Bench Creative Writing19291855
LMArena Text—1447
LMArena Creative Writing—1410
EQ-Bench 4—1234
LMArena Multi-Turn—1449

Frequently asked questions

Is Aion 3.5 better than GPT-5.6 Terra?

GPT-5.6 Terra has enough public results to be ranked (#17); Aion 3.5 does not yet, so treat this comparison as directional.

Which is cheaper, Aion 3.5 or GPT-5.6 Terra?

Aion 3.5 is cheaper. It lists at $3 per million input tokens and $6 per million output tokens; GPT-5.6 Terra lists at $2 and $12.

Which has the bigger context window?

GPT-5.6 Terra does, with 1.05M tokens against 262K.

How many benchmarks do Aion 3.5 and GPT-5.6 Terra share?

1 benchmark has published results for both models. Aion 3.5 has 1 scored results on Noometry and GPT-5.6 Terra has 52.

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