Model comparison

Claude Sonnet 4.5 vs Hy4 preview

Hy4 preview is the stronger model overall, scoring 45.3 to 44.1 on the Noometry Index.

Last verified . 3 shared benchmarks.

Claude Sonnet 4.5 Anthropic

44.1

Rank #81 Confirmed

Hy4 preview Tencent

45.3

Rank #73 Reported

Summary

  • They share 3 benchmarks with published results for both. Claude Sonnet 4.5 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 32.3.
  • The biggest single-benchmark swing is ProofBench: 19% for Claude Sonnet 4.5 and 75% for Hy4 preview.
  • Hy4 preview is cheaper at $0.75 / $2.25 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.5.
  • Hy4 preview accepts more context: 1.05M tokens versus 200K.
  • Hy4 preview has downloadable open weights; the other is API-only.

Side by side

Claude Sonnet 4.5 and Hy4 preview specifications
Claude Sonnet 4.5Hy4 preview
ProviderAnthropicTencent
Noometry Index44.145.3
Released2025-09-292026-08-28
WeightsProprietaryOpen
Context window200K1.05M
Max output64K64K
Input $ / M tokens$3$0.75
Output $ / M tokens$15$2.25
Results tracked733

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Category by category

Coding Hy4 preview leads

Claude Sonnet 4.5: 47.3 (#61), Hy4 preview: 51.6 (#38)

Coding benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
LMArena WebDev13931632
SWE-bench Verified71.3%—
SWE-bench Verified (bash only)71.4%—
SWE-bench Multilingual67%—
SciCode44.7%—
GSO14.7%—
WeirdML47.7%—
LMArena Coding1489—
ALE-Bench796.15—
AlgoTune1.52—

Agentic & Tool Use Not comparable

Claude Sonnet 4.5: 38.3 (#32), Hy4 preview: —

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
Terminal-Bench46.5%—
Berkeley Function Calling Leaderboard73.2%—
GDPval42.5%—
Remote Labor Index2.1%—
τ²-bench Airline72%—
τ²-bench Banking25.3%—
τ²-bench Retail72.4%—
τ²-bench Telecom84.9%—
Cybench60%—
DeepResearch Bench52.6%—
OSWorld62.9%—
LMArena Search1159—
METR Time Horizons67.4%—
Vending-Bench 23,839—

Reasoning Hy4 preview leads

Claude Sonnet 4.5: 26.9 (#125), Hy4 preview: 31.9 (#79)

Reasoning benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
NYT Connections (extended)37.3%68.2%
ARC-AGI-213.6%—
SimpleBench54.3%—
Kagi LLM Benchmark57.9%—
ARC-AGI-163.7%—
CritPt1.1%—
Chess Puzzles12%—
EnigmaEval6%—
EBR-Bench2.4%—
LMArena Hard Prompts1462—
Mystery Game Puzzles17%—
DTBench83.2%—
LMCA38.8%—
Epoch Capabilities Index146.84—
ForecastBench61.9—

Math Hy4 preview leads

Claude Sonnet 4.5: 32.3 (#216), Hy4 preview: 55.7 (#42)

Math benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
ProofBench19%75%
FrontierMath (Tiers 1-3)23.9%—
FrontierMath Tier 42.4%—
OTIS Mock AIME 2024-202577.8%—
Omni-MATH55.3%—
LMArena Math1449—
MATH Level 597.7%—
FrontierMath (Feb 2025 set)15.2%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Not comparable

Claude Sonnet 4.5: 48.4 (#76), Hy4 preview: —

Knowledge benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
GPQA Diamond82.3%—
Humanity's Last Exam13.7%—
SimpleQA Verified30.7%—
MMLU-Pro86.9%—
Vectara Hallucination Rate12%—
GPQA (HELM)68.6%—
LMArena Expert1482—

Multimodal Not comparable

Claude Sonnet 4.5: 34.8 (#89), Hy4 preview: —

Multimodal benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
VPCT39.8%—
LMArena Document1450—

Multilingual Not comparable

Claude Sonnet 4.5: 53.4 (#69), Hy4 preview: —

Multilingual benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
LMArena Non-English1425—
LMArena Chinese1459—
LMArena French1458—
LMArena German1427—
LMArena Japanese1390—
LMArena Korean1403—
LMArena Russian1437—
LMArena Spanish1457—

Instruction Following Not comparable

Claude Sonnet 4.5: 75.0 (#78), Hy4 preview: —

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
IFEval85%—
LMArena Instruction Following1459—

Long Context Not comparable

Claude Sonnet 4.5: 45.2 (#46), Hy4 preview: —

Long Context benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
LMArena Longer Query1476—

Writing & Preference Not comparable

Claude Sonnet 4.5: 66.5 (#34), Hy4 preview: —

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.5Hy4 preview
LMArena Text1439—
LMArena Creative Writing1442—
EQ-Bench Creative Writing1678—
WildBench85.4%—
LMArena Multi-Turn1465—

Frequently asked questions

Is Claude Sonnet 4.5 better than Hy4 preview?

Hy4 preview is the stronger model overall, scoring 45.3 to 44.1 on the Noometry Index.

Which is cheaper, Claude Sonnet 4.5 or Hy4 preview?

Hy4 preview is cheaper. It lists at $0.75 per million input tokens and $2.25 per million output tokens; Claude Sonnet 4.5 lists at $3 and $15.

Is Claude Sonnet 4.5 or Hy4 preview better for coding?

Hy4 preview scores higher on coding benchmarks: 51.6 versus 47.3 in the Noometry coding category.

Which has the bigger context window?

Hy4 preview does, with 1.05M tokens against 200K.

How many benchmarks do Claude Sonnet 4.5 and Hy4 preview share?

3 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and Hy4 preview has 3.

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