Model comparison

GPT-5 Nano vs Hy4 preview

Hy4 preview is the stronger model overall, scoring 45.3 to 33.5 on the Noometry Index. GPT-5 Nano costs 8.2× less per token, which makes it the better buy when Hy4 preview's lead doesn't matter for your workload.

Last verified . 1 shared benchmarks.

GPT-5 Nano OpenAI

33.5

Rank #241 Confirmed

Hy4 preview Tencent

45.3

Rank #73 Reported

Summary

  • They share 1 benchmark with published results for both. GPT-5 Nano scores higher in 0 categories and Hy4 preview in 3 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in math, where Hy4 preview leads 55.7 to 29.4.
  • The biggest single-benchmark swing is ProofBench: 12% for GPT-5 Nano and 75% for Hy4 preview.
  • GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $0.75 / $2.25 for Hy4 preview.
  • Hy4 preview accepts more context: 1.05M tokens versus 400K.
  • Hy4 preview has downloadable open weights; the other is API-only.

Side by side

GPT-5 Nano and Hy4 preview specifications
GPT-5 NanoHy4 preview
ProviderOpenAITencent
Noometry Index33.545.3
Released2025-08-072026-08-28
WeightsProprietaryOpen
Context window400K1.05M
Max output128K64K
Input $ / M tokens$0.05$0.75
Output $ / M tokens$0.40$2.25
Results tracked493

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Category by category

Coding Hy4 preview leads

GPT-5 Nano: 33.6 (#254), Hy4 preview: 51.6 (#38)

Coding benchmarks
BenchmarkGPT-5 NanoHy4 preview
SWE-bench Verified (bash only)34.8%—
LMArena WebDev—1632
WeirdML38.1%—
LMArena Coding1351—
ALE-Bench718.67—

Agentic & Tool Use Not comparable

GPT-5 Nano: 25.8 (#106), Hy4 preview: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5 NanoHy4 preview
Terminal-Bench21.8%—
Berkeley Function Calling Leaderboard51.5%—

Reasoning Hy4 preview leads

GPT-5 Nano: 16.3 (#306), Hy4 preview: 31.9 (#79)

Reasoning benchmarks
BenchmarkGPT-5 NanoHy4 preview
ARC-AGI-22.6%—
Kagi LLM Benchmark62.2%—
NYT Connections (extended)—68.2%
ARC-AGI-120.7%—
Chess Puzzles27%—
LMArena Hard Prompts1328—
Mystery Game Puzzles9%—
DTBench62.7%—
LMCA7.9%—
Epoch Capabilities Index139.38—
ForecastBench59.1—

Math Hy4 preview leads

GPT-5 Nano: 29.4 (#241), Hy4 preview: 55.7 (#42)

Math benchmarks
BenchmarkGPT-5 NanoHy4 preview
ProofBench12%75%
FrontierMath (Tiers 1-3)20%—
FrontierMath Tier 42.4%—
OTIS Mock AIME 2024-202581.1%—
Omni-MATH54.6%—
LMArena Math1317—
MATH Level 595.2%—
FrontierMath (Feb 2025 set)8.3%—
FrontierMath Tier 4 (v1)2.1%—

Knowledge Not comparable

GPT-5 Nano: 35.9 (#178), Hy4 preview: —

Knowledge benchmarks
BenchmarkGPT-5 NanoHy4 preview
GPQA Diamond69.4%—
SimpleQA Verified11.7%—
MMLU-Pro77.8%—
Vectara Hallucination Rate10.5%—
GPQA (HELM)67.9%—
LMArena Expert1321—

Multimodal Not comparable

GPT-5 Nano: 31.3 (#108), Hy4 preview: —

Multimodal benchmarks
BenchmarkGPT-5 NanoHy4 preview
LMArena Vision1159—
VPCT37.2%—

Multilingual Not comparable

GPT-5 Nano: 45.3 (#172), Hy4 preview: —

Multilingual benchmarks
BenchmarkGPT-5 NanoHy4 preview
LMArena Non-English1313—
LMArena Chinese1356—
LMArena German1327—
LMArena Japanese1226—
LMArena Korean1269—
LMArena Russian1296—
LMArena Spanish1360—

Instruction Following Not comparable

GPT-5 Nano: 75.0 (#79), Hy4 preview: —

Instruction Following benchmarks
BenchmarkGPT-5 NanoHy4 preview
IFEval93.2%—
LMArena Instruction Following1306—

Long Context Not comparable

GPT-5 Nano: 31.3 (#281), Hy4 preview: —

Long Context benchmarks
BenchmarkGPT-5 NanoHy4 preview
Fiction.LiveBench44.4%—
LMArena Longer Query1312—

Writing & Preference Not comparable

GPT-5 Nano: 39.1 (#249), Hy4 preview: —

Writing & Preference benchmarks
BenchmarkGPT-5 NanoHy4 preview
LMArena Text1320—
LMArena Creative Writing1249—
EQ-Bench Creative Writing705—
WildBench80.6%—
LMArena Multi-Turn1311—

Frequently asked questions

Is GPT-5 Nano better than Hy4 preview?

Hy4 preview is the stronger model overall, scoring 45.3 to 33.5 on the Noometry Index. GPT-5 Nano costs 8.2× less per token, which makes it the better buy when Hy4 preview's lead doesn't matter for your workload.

Which is cheaper, GPT-5 Nano or Hy4 preview?

GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 per million output tokens; Hy4 preview lists at $0.75 and $2.25.

Is GPT-5 Nano or Hy4 preview better for coding?

Hy4 preview scores higher on coding benchmarks: 51.6 versus 33.6 in the Noometry coding category.

Which has the bigger context window?

Hy4 preview does, with 1.05M tokens against 400K.

How many benchmarks do GPT-5 Nano and Hy4 preview share?

1 benchmark has published results for both models. GPT-5 Nano has 49 scored results on Noometry and Hy4 preview has 3.

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