Model comparison

GPT-5.6 Sol vs Hy4 preview

GPT-5.6 Sol is the stronger model overall, scoring 65.0 to 45.3 on the Noometry Index. Hy4 preview costs 7.1× less per token, which makes it the better buy when GPT-5.6 Sol's lead doesn't matter for your workload.

Last verified . 3 shared benchmarks.

GPT-5.6 Sol OpenAI

65.0

Rank #7 Confirmed

Hy4 preview Tencent

45.3

Rank #73 Reported

Summary

  • They share 3 benchmarks with published results for both. GPT-5.6 Sol scores higher in 3 categories and Hy4 preview in 0 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.6 Sol leads 74.8 to 31.9.
  • The biggest single-benchmark swing is NYT Connections (extended): 93.8% for GPT-5.6 Sol and 68.2% for Hy4 preview.
  • Hy4 preview is cheaper at $0.75 / $2.25 per million input/output tokens, against $4 / $20 for GPT-5.6 Sol.
  • GPT-5.6 Sol accepts more context: 1.05M tokens versus 1.05M.
  • Hy4 preview has downloadable open weights; the other is API-only.

Side by side

GPT-5.6 Sol and Hy4 preview specifications
GPT-5.6 SolHy4 preview
ProviderOpenAITencent
Noometry Index65.045.3
Released2026-07-092026-08-28
WeightsProprietaryOpen
Context window1.05M1.05M
Max output128K64K
Input $ / M tokens$4$0.75
Output $ / M tokens$20$2.25
Results tracked653

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Category by category

Coding GPT-5.6 Sol leads

GPT-5.6 Sol: 65.1 (#7), Hy4 preview: 51.6 (#38)

Coding benchmarks
BenchmarkGPT-5.6 SolHy4 preview
LMArena WebDev16181632
DeepSWE72.7%—
FrontierCode47.5%—
CursorBench41.7%—
FrontierSWE32.2%—
SciCode57.1%—
GSO76.5%—
WeirdML89.4%—
LMArena Coding1498—
MirrorCode20%—
ALE-Bench2,177—

Agentic & Tool Use Not comparable

GPT-5.6 Sol: 50.3 (#7), Hy4 preview: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.6 SolHy4 preview
APEX-Agents51.4%—
OSWorld 2.027.3%—
τ²-bench Banking46.9%—
PostTrainBench36.2%—
BALROG60%—
GBAEval52.6%—
GDP.pdf30.7%—
LMArena Search1257—
Vending-Bench 29,619—

Reasoning GPT-5.6 Sol leads

GPT-5.6 Sol: 74.8 (#8), Hy4 preview: 31.9 (#79)

Reasoning benchmarks
BenchmarkGPT-5.6 SolHy4 preview
NYT Connections (extended)93.8%68.2%
ARC-AGI-292.5%—
SimpleBench71.7%—
Kagi LLM Benchmark67%—
ARC-AGI-197.5%—
CritPt32.3%—
Chess Puzzles64%—
EnigmaEval37.1%—
EBR-Bench44.8%—
LMArena Hard Prompts1484—
Mystery Game Puzzles58%—
DTBench96%—
LMCA59.2%—
Surface Evolver Bench93.1%—
Bench to the Future 30.14—
Epoch Capabilities Index161.66—

Math GPT-5.6 Sol leads

GPT-5.6 Sol: 85.6 (#9), Hy4 preview: 55.7 (#42)

Math benchmarks
BenchmarkGPT-5.6 SolHy4 preview
ProofBench83%75%
FrontierMath (Tiers 1-3)89.1%—
FrontierMath Tier 482.9%—
OTIS Mock AIME 2024-2025100%—
LMArena Math1474—
FrontierMath Erdős0%—

Knowledge Not comparable

GPT-5.6 Sol: 64.3 (#18), Hy4 preview: —

Knowledge benchmarks
BenchmarkGPT-5.6 SolHy4 preview
GPQA Diamond93.5%—
SimpleQA Verified69.7%—
Vectara Hallucination Rate12.4%—
LMArena Expert1516—

Multimodal Not comparable

GPT-5.6 Sol: 48.6 (#9), Hy4 preview: —

Multimodal benchmarks
BenchmarkGPT-5.6 SolHy4 preview
LMArena Vision1281—
Blueprint-Bench 233.6%—
Furniture Assembly56.7%—
LMArena Document1483—

Multilingual Not comparable

GPT-5.6 Sol: 55.3 (#32), Hy4 preview: —

Multilingual benchmarks
BenchmarkGPT-5.6 SolHy4 preview
LMArena Non-English1452—
LMArena Chinese1527—
LMArena French1477—
LMArena German1476—
LMArena Japanese1471—
LMArena Korean1442—
LMArena Russian1468—
LMArena Spanish1441—

Instruction Following Not comparable

GPT-5.6 Sol: 77.7 (#16), Hy4 preview: —

Instruction Following benchmarks
BenchmarkGPT-5.6 SolHy4 preview
LMArena Instruction Following1482—

Long Context Not comparable

GPT-5.6 Sol: 45.4 (#42), Hy4 preview: —

Long Context benchmarks
BenchmarkGPT-5.6 SolHy4 preview
LMArena Longer Query1480—

Writing & Preference Not comparable

GPT-5.6 Sol: 73.3 (#12), Hy4 preview: —

Writing & Preference benchmarks
BenchmarkGPT-5.6 SolHy4 preview
LMArena Text1457—
LMArena Creative Writing1448—
EQ-Bench Creative Writing1972—
EQ-Bench 41250—
LMArena Multi-Turn1460—

Frequently asked questions

Is GPT-5.6 Sol better than Hy4 preview?

GPT-5.6 Sol is the stronger model overall, scoring 65.0 to 45.3 on the Noometry Index. Hy4 preview costs 7.1× less per token, which makes it the better buy when GPT-5.6 Sol's lead doesn't matter for your workload.

Which is cheaper, GPT-5.6 Sol or Hy4 preview?

Hy4 preview is cheaper. It lists at $0.75 per million input tokens and $2.25 per million output tokens; GPT-5.6 Sol lists at $4 and $20.

Is GPT-5.6 Sol or Hy4 preview better for coding?

GPT-5.6 Sol scores higher on coding benchmarks: 65.1 versus 51.6 in the Noometry coding category.

Which has the bigger context window?

GPT-5.6 Sol does, with 1.05M tokens against 1.05M.

How many benchmarks do GPT-5.6 Sol and Hy4 preview share?

3 benchmarks have published results for both models. GPT-5.6 Sol has 65 scored results on Noometry and Hy4 preview has 3.

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