Noometry

Model comparison

Claude Opus 5.5 vs Llama 3.1-8B

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 23.0 on the Noometry Index. Llama 3.1-8B costs 139× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Last verified . 22 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

Llama 3.1-8B Meta

23.0

Rank #352 Confirmed

Summary

  • They share 22 benchmarks with published results for both. Claude Opus 5.5 scores higher in 9 categories and Llama 3.1-8B in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5.5 leads 91.8 to 10.2.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Opus 5.5 and 1.7% for Llama 3.1-8B.
  • Llama 3.1-8B is cheaper at $0.05 / $0.08 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 128K.
  • Llama 3.1-8B has downloadable open weights; the other is API-only.

Side by side

Claude Opus 5.5Llama 3.1-8B
ProviderAnthropicMeta
Noometry Index68.623.0
Released2026-09-222024-07-23
WeightsProprietaryOpen
Context window1M128K
Max output128K4K
Input $ / M tokens$4$0.05
Output $ / M tokens$20$0.08
Results tracked4443

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.9 (#3), Llama 3.1-8B: 20.2 (#340)

BenchmarkClaude Opus 5.5Llama 3.1-8B
SciCode66.9%13.2%
LMArena Coding15471195
FrontierCode54.6%—
CursorBench57.8%—
LMArena WebDev1813—
FrontierSWE62.3%—
WeirdML—1.7%
BigCodeBench Instruct—32.8%
MirrorCode77.4%—
BigCodeBench Complete—40.5%
ALE-Bench2,147—
HumanEval+—62.8%
MBPP+—55.6%

Agentic & Tool Use Claude Opus 5.5 leads

Claude Opus 5.5: 45.3 (#15), Llama 3.1-8B: 22.5 (#131)

BenchmarkClaude Opus 5.5Llama 3.1-8B
APEX-Agents73.5%—
Berkeley Function Calling Leaderboard—25.8%
BALROG—15.1%
GDP.pdf30.6%—
Vending-Bench 29,235—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 80.2 (#3), Llama 3.1-8B: 14.9 (#321)

BenchmarkClaude Opus 5.5Llama 3.1-8B
CritPt31.7%0%
LMArena Hard Prompts15351175
DTBench98.9%50.9%
LMCA68.2%5.4%
Epoch Capabilities Index167.33116.57
ARC-AGI-293.3%—
NYT Connections (extended)88.5%—
ARC-AGI-198.5%—
Chess Puzzles—0%
EBR-Bench71.4%—
Mystery Game Puzzles71%—
PIQA—81.2%

Math Claude Opus 5.5 leads

Claude Opus 5.5: 91.8 (#3), Llama 3.1-8B: 10.2 (#317)

BenchmarkClaude Opus 5.5Llama 3.1-8B
OTIS Mock AIME 2024-2025100%1.7%
LMArena Math15061179
FrontierMath (Tiers 1-3)91.2%—
FrontierMath Tier 495%—
ProofBench100%—
Omni-MATH—13.7%
MATH Level 5—22.9%
FrontierMath Erdős2.9%—
GSM8K—82.4%

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), Llama 3.1-8B: 8.0 (#307)

BenchmarkClaude Opus 5.5Llama 3.1-8B
GPQA Diamond90.6%27%
LMArena Expert15471144
SimpleQA Verified72.2%—
MMLU-Pro—40.6%
GPQA (HELM)—24.7%
BoolQ—82.8%
MMLU—56.1%

Multimodal Not comparable

Claude Opus 5.5: 57.8 (#1), Llama 3.1-8B: —

BenchmarkClaude Opus 5.5Llama 3.1-8B
LMArena Vision1321—
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.1 (#2), Llama 3.1-8B: 34.0 (#249)

BenchmarkClaude Opus 5.5Llama 3.1-8B
LMArena Non-English15071148
LMArena Chinese15881151
LMArena French15141177
LMArena Russian15201158
LMArena Spanish15071169
LMArena German—1144
LMArena Japanese—1061
LMArena Korean—1053

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.0 (#3), Llama 3.1-8B: 58.9 (#258)

BenchmarkClaude Opus 5.5Llama 3.1-8B
LMArena Instruction Following15371159
IFEval—74.3%

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.1 (#19), Llama 3.1-8B: 35.8 (#238)

BenchmarkClaude Opus 5.5Llama 3.1-8B
LMArena Longer Query15321182

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.2 (#3), Llama 3.1-8B: 29.7 (#290)

BenchmarkClaude Opus 5.5Llama 3.1-8B
LMArena Text15151187
LMArena Creative Writing15331154
EQ-Bench Creative Writing2050713
LMArena Multi-Turn14991172
WildBench—68.7%

Frequently asked questions

Is Claude Opus 5.5 better than Llama 3.1-8B?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 23.0 on the Noometry Index. Llama 3.1-8B costs 139× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5.5 or Llama 3.1-8B?

Llama 3.1-8B is cheaper. It lists at $0.05 per million input tokens and $0.08 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Is Claude Opus 5.5 or Llama 3.1-8B better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 20.2 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 128K.

How many benchmarks do Claude Opus 5.5 and Llama 3.1-8B share?

22 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Llama 3.1-8B has 43.

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