Model comparison

GPT-5.5 vs Hy4 preview

GPT-5.5 is the stronger model overall, scoring 63.4 to 45.3 on the Noometry Index. Hy4 preview costs 10.0× less per token, which makes it the better buy when GPT-5.5's lead doesn't matter for your workload.

Last verified . 3 shared benchmarks.

GPT-5.5 OpenAI

63.4

Rank #9 Confirmed

Hy4 preview Tencent

45.3

Rank #73 Reported

Summary

  • They share 3 benchmarks with published results for both. GPT-5.5 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-5.5 leads 72.8 to 31.9.
  • The biggest single-benchmark swing is NYT Connections (extended): 96.2% for GPT-5.5 and 68.2% for Hy4 preview.
  • Hy4 preview is cheaper at $0.75 / $2.25 per million input/output tokens, against $5 / $30 for GPT-5.5.
  • GPT-5.5 accepts more context: 1.05M tokens versus 1.05M.
  • Hy4 preview has downloadable open weights; the other is API-only.

Side by side

GPT-5.5 and Hy4 preview specifications
GPT-5.5Hy4 preview
ProviderOpenAITencent
Noometry Index63.445.3
Released2026-04-232026-08-28
WeightsProprietaryOpen
Context window1.05M1.05M
Max output128K64K
Input $ / M tokens$5$0.75
Output $ / M tokens$30$2.25
Results tracked713

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Category by category

Coding GPT-5.5 leads

GPT-5.5: 58.2 (#17), Hy4 preview: 51.6 (#38)

Coding benchmarks
BenchmarkGPT-5.5Hy4 preview
LMArena WebDev15131632
SWE-bench Verified80.6%—
DeepSWE67%—
FrontierCode43%—
SciCode56.1%—
GSO40.2%—
WeirdML84.9%—
LMArena Coding1494—
MirrorCode10%—
ALE-Bench1,943—

Agentic & Tool Use Not comparable

GPT-5.5: 50.7 (#6), Hy4 preview: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.5Hy4 preview
Terminal-Bench84.7%—
APEX-Agents55.1%—
OSWorld 2.013%—
Remote Labor Index6.3%—
τ²-bench Banking44.6%—
DeepResearch Bench54%—
PostTrainBench27.2%—
ExploitBench47.4%—
GBAEval53.2%—
GDP.pdf26%—
LMArena Search1242—
Vending-Bench 27,524—

Reasoning GPT-5.5 leads

GPT-5.5: 72.8 (#11), Hy4 preview: 31.9 (#79)

Reasoning benchmarks
BenchmarkGPT-5.5Hy4 preview
NYT Connections (extended)96.2%68.2%
ARC-AGI-285%—
SimpleBench69%—
Kagi LLM Benchmark88.8%—
ARC-AGI-195%—
CritPt27.1%—
Chess Puzzles54%—
EBR-Bench34.3%—
LMArena Hard Prompts1489—
Mystery Game Puzzles56%—
DTBench96%—
LMCA54.3%—
Surface Evolver Bench88.1%—
Bench to the Future 30.14—
Epoch Capabilities Index159.1—
ForecastBench60.6—

Math GPT-5.5 leads

GPT-5.5: 81.7 (#11), Hy4 preview: 55.7 (#42)

Knowledge Not comparable

GPT-5.5: 64.4 (#17), Hy4 preview: —

Knowledge benchmarks
BenchmarkGPT-5.5Hy4 preview
GPQA Diamond94%—
SimpleQA Verified63%—
Vectara Hallucination Rate9.3%—
LMArena Expert1508—

Multimodal Not comparable

GPT-5.5: 46.9 (#12), Hy4 preview: —

Multimodal benchmarks
BenchmarkGPT-5.5Hy4 preview
LMArena Vision1297—
Blueprint-Bench 236.2%—
Furniture Assembly44.2%—
LMArena Document1486—

Multilingual Not comparable

GPT-5.5: 56.4 (#20), Hy4 preview: —

Multilingual benchmarks
BenchmarkGPT-5.5Hy4 preview
LMArena Non-English1467—
LMArena Chinese1533—
LMArena French1486—
LMArena German1480—
LMArena Japanese1498—
LMArena Korean1460—
LMArena Russian1473—
LMArena Spanish1468—

Instruction Following Not comparable

GPT-5.5: 77.5 (#18), Hy4 preview: —

Instruction Following benchmarks
BenchmarkGPT-5.5Hy4 preview
LMArena Instruction Following1479—

Long Context Not comparable

GPT-5.5: 48.3 (#12), Hy4 preview: —

Long Context benchmarks
BenchmarkGPT-5.5Hy4 preview
CL-bench Life22.2%—
LMArena Longer Query1484—

Writing & Preference Not comparable

GPT-5.5: 72.7 (#13), Hy4 preview: —

Writing & Preference benchmarks
BenchmarkGPT-5.5Hy4 preview
LMArena Text1472—
LMArena Creative Writing1455—
EQ-Bench Creative Writing1844—
EQ-Bench 41315—
LMArena Multi-Turn1476—

Frequently asked questions

Is GPT-5.5 better than Hy4 preview?

GPT-5.5 is the stronger model overall, scoring 63.4 to 45.3 on the Noometry Index. Hy4 preview costs 10.0× less per token, which makes it the better buy when GPT-5.5's lead doesn't matter for your workload.

Which is cheaper, GPT-5.5 or Hy4 preview?

Hy4 preview is cheaper. It lists at $0.75 per million input tokens and $2.25 per million output tokens; GPT-5.5 lists at $5 and $30.

Is GPT-5.5 or Hy4 preview better for coding?

GPT-5.5 scores higher on coding benchmarks: 58.2 versus 51.6 in the Noometry coding category.

Which has the bigger context window?

GPT-5.5 does, with 1.05M tokens against 1.05M.

How many benchmarks do GPT-5.5 and Hy4 preview share?

3 benchmarks have published results for both models. GPT-5.5 has 71 scored results on Noometry and Hy4 preview has 3.

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