Noometry

Model comparison

Claude Opus 5.5 vs Hermes 4 405B

Claude Opus 5.5 has enough public results to be ranked (#3); Hermes 4 405B does not yet, so treat this comparison as directional.

Last verified . 1 shared benchmarks.

Claude Opus 5.5 Anthropic

68.5

Rank #3 Confirmed

Hermes 4 405B Nous Research

37.1

Unranked Sparse

Summary

  • They share 1 benchmark with published results for both. Claude Opus 5.5 scores higher in 2 categories and Hermes 4 405B in 0 categories; 2 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 5.5 leads 79.5 to 25.3.
  • Hermes 4 405B is cheaper at $1 / $3 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 131K.
  • Hermes 4 405B has downloadable open weights; the other is API-only.

Side by side

Claude Opus 5.5Hermes 4 405B
ProviderAnthropicNous Research
Noometry Index68.537.1
Released2026-09-22—
WeightsProprietaryOpen
Context window1M131K
Max output128K118K
Input $ / M tokens$4$1
Output $ / M tokens$20$3
Results tracked352

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Category by category

Coding Not comparable

Claude Opus 5.5: 71.4 (#1), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
FrontierCode54.4%—
CursorBench57.8%—
LMArena WebDev1820—
FrontierSWE62.3%—
SciCode66.9%—
LMArena Coding1545—
MirrorCode77.4%—

Agentic & Tool Use Not comparable

Claude Opus 5.5: 45.3 (#13), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
APEX-Agents73.5%—
GDP.pdf30.6%—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 79.5 (#2), Hermes 4 405B: 25.3

BenchmarkClaude Opus 5.5Hermes 4 405B
ARC-AGI-292.5%—
Kagi LLM Benchmark—55.8%
NYT Connections (extended)88.5%—
ARC-AGI-197.5%—
CritPt31.7%—
EBR-Bench71.4%—
LMArena Hard Prompts1545—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—

Math Not comparable

Claude Opus 5.5: 92.4 (#2), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
FrontierMath (Tiers 1-3)91.2%—
FrontierMath Tier 495%—
OTIS Mock AIME 2024-2025100%—
ProofBench100%—

Knowledge Not comparable

Claude Opus 5.5: 66.6 (#9), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
GPQA Diamond90.6%—
SimpleQA Verified72.2%—
LMArena Expert1564—

Multimodal Not comparable

Claude Opus 5.5: 56.5 (#2), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
Furniture Assembly83.3%—

Multilingual Not comparable

Claude Opus 5.5: 59.8 (#1), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
LMArena Non-English1513—
LMArena Chinese1572—
LMArena Russian1532—

Instruction Following Not comparable

Claude Opus 5.5: 80.1 (#2), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
LMArena Instruction Following1535—

Long Context Not comparable

Claude Opus 5.5: 47.3 (#18), Hermes 4 405B: —

BenchmarkClaude Opus 5.5Hermes 4 405B
LMArena Longer Query1540—

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.7 (#3), Hermes 4 405B: 53.0

BenchmarkClaude Opus 5.5Hermes 4 405B
EQ-Bench Creative Writing20501421
LMArena Text1518—
LMArena Creative Writing1538—
LMArena Multi-Turn1520—

Frequently asked questions

Is Claude Opus 5.5 better than Hermes 4 405B?

Claude Opus 5.5 has enough public results to be ranked (#3); Hermes 4 405B does not yet, so treat this comparison as directional.

Which is cheaper, Claude Opus 5.5 or Hermes 4 405B?

Hermes 4 405B is cheaper. It lists at $1 per million input tokens and $3 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 131K.

How many benchmarks do Claude Opus 5.5 and Hermes 4 405B share?

1 benchmark has published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and Hermes 4 405B has 2.

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