Claude Opus 4.5 vs Llama 3.1 Instruct 405B
Wins 5 of 6 areas
Coding · Agents · Reasoning · Long documents · Following instructions
Wins 0 of 6 areas
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Claude Opus 4.5 is the stronger all-rounder.
Scores updated · 23 tests both models report · How we compare
Where each one wins
Tests won in each of the six areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- CodingWriting and fixing software40Claude Opus 4.54 of 4 tests
- ReasoningHard problems that need careful thinking30Claude Opus 4.53 of 3 tests
- Long documentsFinding answers in very long texts20Claude Opus 4.52 of 2 tests
- AgentsCarrying out multi-step tasks on its own10Claude Opus 4.51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Opus 4.51 of 1 test
- FactsGetting facts right instead of making them up11Even1 each
Agents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Opus 4.5 pulls ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+56.4points ahead
- Reasons across sets of long documentsAA-LCR+52points ahead
- Long, multi-file coding tasks in real codebasesSWE-bench Pro+40.8points ahead
Where Llama 3.1 Instruct 405B pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+8.6points ahead
Every test, side by side
All 23 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 4.5
- SWE-bench VerifiedClaude Opus 4.5 by 56.480.924.5+56.4
- SWE-bench ProClaude Opus 4.5 by 40.85211.2+40.8
- Terminal-Bench HardClaude Opus 4.5 by 40.2476.8+40.2
- SciCodeClaude Opus 4.5 by 19.649.529.9+19.6
ReasoningClaude Opus 4.5
- GPQA DiamondClaude Opus 4.5 by 35.186.651.5+35.1
- Humanity's Last ExamClaude Opus 4.5 by 26.130.14+26.1
- CritPtClaude Opus 4.5 by 4.64.60+4.6
FactsEven
- AA-Omniscience · AccuracyClaude Opus 4.5 by 23.446.623.2+23.4
- AA-Omniscience · Non-hallucinationLlama 3.1 Instruct 405B by 8.63947.6+8.6
Long documentsClaude Opus 4.5
- AA-LCRClaude Opus 4.5 by 5277.325.3+52
- LongBench v2Claude Opus 4.5 by 28.364.436.1+28.3
Following instructionsClaude Opus 4.5
- IFBenchClaude Opus 4.5 by 195839+19
Other results10 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- τ²-Bench Telecom (AA run)Claude Opus 4.5 by 70.589.519+70.5
- LiveCodeBenchClaude Opus 4.5 by 59.38727.7+59.3
- AA Agentic IndexClaude Opus 4.5 by 53.359.66.3+53.3
- Artificial Analysis Coding IndexClaude Opus 4.5 by 33.347.814.5+33.3
- AA-OmniscienceClaude Opus 4.5 by 31.114-17.1+31.1
- AA IntelligenceClaude Opus 4.5 by 21.829.17.3+21.8
- C-EvalClaude Opus 4.5 by 19.792.272.5+19.7
- MMMLUClaude Opus 4.5 by 1790.873.8+17
- MMLU-ProClaude Opus 4.5 by 16.289.573.3+16.2
- MMLU-ReduxClaude Opus 4.5 by 9.495.686.2+9.4
Questions people ask
Which is better, Claude Opus 4.5 or Llama 3.1 Instruct 405B?
Claude Opus 4.5 wins five of the six areas where both have results: coding, agents, reasoning, long documents and following instructions. Llama 3.1 Instruct 405B wins none. They are level on facts.
Which is better for coding?
Claude Opus 4.5. It wins 4 of the 4 coding tests both models report; Llama 3.1 Instruct 405B wins none.
How do you compare the two?
We use the 23 benchmark tests both models have published scores on. The verdict counts the 13 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 10 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.