Model comparison

GPT-5.6 Terra vs Step 3

GPT-5.6 Terra is the stronger model overall, scoring 59.1 to 39.9 on the Noometry Index.

Last verified . 17 shared benchmarks.

GPT-5.6 Terra OpenAI

59.1

Rank #15 Confirmed

Step 3 StepFun

39.9

Rank #145 Confirmed

Summary

  • They share 17 benchmarks with published results for both. GPT-5.6 Terra scores higher in 9 categories and Step 3 in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Terra leads 81.5 to 34.9.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 51.3% for GPT-5.6 Terra and 62.3% for Step 3.
  • Step 3 has downloadable open weights; the other is API-only.

Side by side

GPT-5.6 Terra and Step 3 specifications
GPT-5.6 TerraStep 3
ProviderOpenAIStepFun
Noometry Index59.139.9
Released2026-07-09—
WeightsProprietaryOpen
Context window1.05M—
Max output128K—
Input $ / M tokens$2—
Output $ / M tokens$12—
Results tracked5217

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding GPT-5.6 Terra leads

GPT-5.6 Terra: 57.1 (#16), Step 3: 39.5 (#144)

Coding benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Coding14841367
DeepSWE69.6%—
FrontierCode41.3%—
CursorBench41.3%—
LMArena WebDev1520—
SciCode55%—
WeirdML78.3%—
ALE-Bench1,951—

Agentic & Tool Use Not comparable

GPT-5.6 Terra: 40.2 (#23), Step 3: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.6 TerraStep 3
APEX-Agents58.2%—
BALROG53.2%—
GDP.pdf24.7%—
Vending-Bench 27,343—

Reasoning GPT-5.6 Terra leads

GPT-5.6 Terra: 60.6 (#19), Step 3: 27.6 (#102)

Reasoning benchmarks
BenchmarkGPT-5.6 TerraStep 3
Kagi LLM Benchmark51.3%62.3%
LMArena Hard Prompts14671355
ARC-AGI-283.9%—
SimpleBench48.9%—
NYT Connections (extended)78.4%—
ARC-AGI-196.5%—
CritPt30%—
Chess Puzzles54%—
Mystery Game Puzzles35%—
DTBench93.3%—
LMCA55%—
Surface Evolver Bench83.8%—
Epoch Capabilities Index159.31—

Math GPT-5.6 Terra leads

GPT-5.6 Terra: 81.5 (#10), Step 3: 34.9 (#148)

Math benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Math14631366
FrontierMath (Tiers 1-3)86%—
FrontierMath Tier 470.7%—
OTIS Mock AIME 2024-202599.7%—
ProofBench74%—

Knowledge GPT-5.6 Terra leads

GPT-5.6 Terra: 61.3 (#27), Step 3: 36.2 (#161)

Knowledge benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Expert14921333
GPQA Diamond93.3%—
SimpleQA Verified43.2%—

Multimodal GPT-5.6 Terra leads

GPT-5.6 Terra: 47.5 (#10), Step 3: 34.9 (#81)

Multimodal benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Vision12711176
Blueprint-Bench 230.8%—
Furniture Assembly54.2%—
LMArena Document1472—

Multilingual GPT-5.6 Terra leads

GPT-5.6 Terra: 54.5 (#42), Step 3: 46.5 (#154)

Multilingual benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Non-English14391327
LMArena Chinese15141396
LMArena German14621371
LMArena Korean14201271
LMArena Russian14501331
LMArena Spanish14551372
LMArena French1476—
LMArena Japanese1446—

Instruction Following GPT-5.6 Terra leads

GPT-5.6 Terra: 76.6 (#38), Step 3: 70.6 (#159)

Instruction Following benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Instruction Following14531332

Long Context GPT-5.6 Terra leads

GPT-5.6 Terra: 44.4 (#64), Step 3: 40.3 (#152)

Long Context benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Longer Query14521326

Writing & Preference GPT-5.6 Terra leads

GPT-5.6 Terra: 70.4 (#21), Step 3: 54.5 (#146)

Writing & Preference benchmarks
BenchmarkGPT-5.6 TerraStep 3
LMArena Text14461351
LMArena Creative Writing14111322
LMArena Multi-Turn14511340
EQ-Bench Creative Writing1855—
EQ-Bench 41234—

Frequently asked questions

Is GPT-5.6 Terra better than Step 3?

GPT-5.6 Terra is the stronger model overall, scoring 59.1 to 39.9 on the Noometry Index.

Is GPT-5.6 Terra or Step 3 better for coding?

GPT-5.6 Terra scores higher on coding benchmarks: 57.1 versus 39.5 in the Noometry coding category.

How many benchmarks do GPT-5.6 Terra and Step 3 share?

17 benchmarks have published results for both models. GPT-5.6 Terra has 52 scored results on Noometry and Step 3 has 17.

Related comparisons

Go deeper