Pairwise benchmark snapshot · Aug 16, 2026

Claude Sonnet 4.5 vs Llama 3.1 405B benchmark

Name: Claude Sonnet 4.5 vs Llama 3.1 405B AI benchmark comparison
Creator: CompareLLM
License: https://creativecommons.org/licenses/by/4.0/

This page compares Claude Sonnet 4.5 (Anthropic) and Llama 3.1 405B (Meta) using the latest snapshots we have as of Aug 16, 2026. On preference Elo, Claude Sonnet 4.5 is ahead by 154 points (1,524 vs 1,370; seed-bootstrap (Aug 1, 2026)). On SWE-bench coding, Claude Sonnet 4.5 resolves 70.1% versus 58.4% (seed-bootstrap (Aug 1, 2026)). Claude Sonnet 4.5 streams faster (88 tok/s) while Llama 3.1 405B is the cheaper output token ($3.5/1M). Claude Sonnet 4.5 has the larger context window (1M tokens). Every cell below is a dated snapshot from a named public source — we do not invent missing scores, and we do not run SWE-bench ourselves.

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Anthropic

Claude Sonnet 4.5

Workhorse Anthropic model: most of Opus coding quality at a mid-tier price.

Elo 1,524$15/1M out

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Quick vs:vs Claude Opus 4.5 vs Claude Opus 4.6 vs Claude 3.7 Sonnet vs GPT-5

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

Claude Sonnet 4.5 (8)vsLlama 3.1 405B (2)

Claude Sonnet 4.5: 8W (80%)Overall: Claude Sonnet 4.5Llama 3.1 405B: 2W (20%)

← Claude Sonnet 4.5Llama 3.1 405B →

Claude Sonnet 4.5 (5/5)

Intelligence & Reasoning

Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy

Preference Elo

1,524vs1,370

Coding Elo

1,531vs1,385

SWE-bench

70.1%vs58.4%

LiveBench

67.4%vs61.2%

GPQA Diamond

80.2%vs75.2%

Claude Sonnet 4.5: 5WLlama 3.1 405B: 0W

Claude Sonnet 4.5 (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

88 tok/svs42 tok/s

Time to first token

240 msvs360 ms

Claude Sonnet 4.5: 2WLlama 3.1 405B: 0W

Llama 3.1 405B (2/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$15/1Mvs$3.5/1M

Input price

$3/1Mvs$1.25/1M

Context window

1Mvs128k

Claude Sonnet 4.5: 1WLlama 3.1 405B: 2W

Capability Matchup Radar

Multi-Dimensional Capability Radar

Each spoke is a skill. Farther from the center is better (0–100th percentile). Tap any dot to inspect details.

Tap any node to inspect

Percentile 0–100

Dimensional AdvantageClaude Sonnet 4.5 5/6

Preference Elo

Claude Sonnet 4.5

154 pts advantage

Throughput Speed

Claude Sonnet 4.5

46 tok/s faster

Price Efficiency

Llama 3.1 405B

$11.50/1M cheaper

Full Benchmark Score Matrix

—

Elo

High is better

+11%1,524

EloHigh is better

1,370

Code Elo

High is better

+11%1,531

Code EloHigh is better

1,385

LiveBench

High is better

+10%67.4%

LiveBenchHigh is better

61.2%

SWE-bench

High is better

+20%70.1%

SWE-benchHigh is better

58.4%

GPQA

High is better

+7%80.2%

GPQAHigh is better

75.2%

TTFT

Low is better

+50%240 ms

TTFTLow is better

360 ms

Speed

High is better

+110%88 tok/s

SpeedHigh is better

42 tok/s

In $

Low is better

$3/1M

In $Low is better

$1.25/1M+140%

Out $

Low is better

$15/1M

Out $Low is better

$3.5/1M+329%

Context

High is better

+681%1M

ContextHigh is better

128k

Interactive Simulator

Workload Cost & Savings Calculator

Simulate monthly production API costs based on published $/1M tokens.

Save up to 71% with Llama 3.1 405B

Monthly Volume50M tokens/mo

Quick Presets:

Token Ratio (In vs Out)70% In / 30% Out

RAG / Search (10% out)Coding / Chat (50% out)

Claude Sonnet 4.5$330.00 / mo

In: $105.00Out: $225.00

Llama 3.1 405B$96.25 / mo

In: $43.75Out: $52.50

Estimated Cost Delta

Llama 3.1 405B is estimated to save $233.75/month ($2,805/year).

Based on 50M tokens (30% gen)

Key Selection Recommendations

1
Claude Sonnet 4.5:Pick Claude Sonnet 4.5 when repo-level coding accuracy is the constraint.
2
Llama 3.1 405B:Pick Llama 3.1 405B when you are optimizing output cost.
3
Claude Sonnet 4.5:Pick Claude Sonnet 4.5 when time-to-first-token matters more than peak Elo.

Recommended Workload Routing

Repo / coding agentsClaude Sonnet 4.5

Higher SWE-bench (70.1%).

High-volume chatLlama 3.1 405B

Lower output list price ($3.5/1M).

Voice / low-latency UIClaude Sonnet 4.5

Lower TTFT (240 ms).

Long-document RAGClaude Sonnet 4.5

Larger window (1M).

Screenshots / visionClaude Sonnet 4.5

Claude Sonnet 4.5 is the side marked multimodal in the catalog.

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	Claude Sonnet 4.5	Higher SWE-bench (70.1%).
High-volume chat	Llama 3.1 405B	Lower output list price ($3.5/1M).
Voice / low-latency UI	Claude Sonnet 4.5	Lower TTFT (240 ms).
Long-document RAG	Claude Sonnet 4.5	Larger window (1M).
Screenshots / vision	Claude Sonnet 4.5	Claude Sonnet 4.5 is the side marked multimodal in the catalog.

Related Editorial Dispatches & Benchmark Notes

View all news

launchFeb 18, 2026

Claude Sonnet 4.5 is the previous workhorse — still a valid vs baseline

Most of Opus 4.5 coding at a mid-tier price. Sonnet 5 replaced it as the buy; 4.5 remains a compare baseline.

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LIVE

Anthropic

Claude Sonnet 4.5

Elo 1,524

LiveBench67.4%

SWE-bench70.1%

Speed88 tok/s

Output cost$15/1M

Llama 3.1 405B

Elo 1,370

LiveBench61.2%

SWE-bench58.4%

Speed42 tok/s

Output cost$3.5/1M

Frequently Asked Questions

Which is better overall, Claude Sonnet 4.5 or Llama 3.1 405B?: Claude Sonnet 4.5 has the higher preference Elo in our latest snapshot (1,524). “Better” still depends on coding, price, and latency — see the table.
Which is better at coding, Claude Sonnet 4.5 or Llama 3.1 405B?: Claude Sonnet 4.5 leads SWE-bench at 70.1% vs 58.4%. SWE-bench is one harness, not your repo.
Which is cheaper to run in production?: Llama 3.1 405B output tokens are $3.5/1M versus $15/1M. Input prices and retry rates still move the real bill.
Which is faster, Claude Sonnet 4.5 or Llama 3.1 405B?: Claude Sonnet 4.5 has the lower time-to-first-token (240 ms vs 360 ms). Tokens/sec is a separate column if you care about long completions.
Which has the larger context window?: Claude Sonnet 4.5 accepts 1M tokens versus 128k.
Can I self-host either model?: Llama 3.1 405B is marked open-weights in our catalog. The other side is a closed API. Check the provider license before you ship weights.
Are these scores from CompareLLM’s own evals?: No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.
What does preference Elo mean on this page?: Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. Claude Sonnet 4.5 and Llama 3.1 405B Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Similar Head-to-Head Comparisons

All Claude Sonnet 4.5 matchups →|All Llama 3.1 405B matchups →

Claude Sonnet 4.5 vs Claude Sonnet 4 (previous sonnet)Claude Sonnet 4.5 vs Claude Sonnet 5 (next sonnet)Llama 3.1 405B vs Llama 3.1 70B (next llama)Claude Opus 4.5 vs Claude Sonnet 4.5 Claude Opus 4.6 vs Claude Sonnet 4.5 Llama 4 Maverick vs Claude Sonnet 4.5

Claude Sonnet 4.5 vs Llama 3.1 405B benchmark

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

Claude Sonnet 4.5 (8)vsLlama 3.1 405B (2)

Claude Sonnet 4.5: 8W (80%)Overall: Claude Sonnet 4.5Llama 3.1 405B: 2W (20%)

← Claude Sonnet 4.5Llama 3.1 405B →

Claude Sonnet 4.5 (5/5)

Intelligence & Reasoning

Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy

Preference Elo

1,524vs1,370

Coding Elo

1,531vs1,385

SWE-bench

70.1%vs58.4%

LiveBench

67.4%vs61.2%

GPQA Diamond

80.2%vs75.2%

Claude Sonnet 4.5: 5WLlama 3.1 405B: 0W

Claude Sonnet 4.5 (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

88 tok/svs42 tok/s

Time to first token

240 msvs360 ms

Claude Sonnet 4.5: 2WLlama 3.1 405B: 0W

Llama 3.1 405B (2/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$15/1Mvs$3.5/1M

Input price

$3/1Mvs$1.25/1M

Context window

1Mvs128k

Claude Sonnet 4.5: 1WLlama 3.1 405B: 2W

Recommended Workload Routing

Repo / coding agentsClaude Sonnet 4.5

Higher SWE-bench (70.1%).

High-volume chatLlama 3.1 405B

Lower output list price ($3.5/1M).

Voice / low-latency UIClaude Sonnet 4.5

Lower TTFT (240 ms).

Long-document RAGClaude Sonnet 4.5

Larger window (1M).

Screenshots / visionClaude Sonnet 4.5

Claude Sonnet 4.5 is the side marked multimodal in the catalog.

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	Claude Sonnet 4.5	Higher SWE-bench (70.1%).
High-volume chat	Llama 3.1 405B	Lower output list price ($3.5/1M).
Voice / low-latency UI	Claude Sonnet 4.5	Lower TTFT (240 ms).
Long-document RAG	Claude Sonnet 4.5	Larger window (1M).
Screenshots / vision	Claude Sonnet 4.5	Claude Sonnet 4.5 is the side marked multimodal in the catalog.

Frequently Asked Questions

Which is better overall, Claude Sonnet 4.5 or Llama 3.1 405B?

Claude Sonnet 4.5 has the higher preference Elo in our latest snapshot (1,524). “Better” still depends on coding, price, and latency — see the table.

Which is better at coding, Claude Sonnet 4.5 or Llama 3.1 405B?

Claude Sonnet 4.5 leads SWE-bench at 70.1% vs 58.4%. SWE-bench is one harness, not your repo.

Which is cheaper to run in production?

Llama 3.1 405B output tokens are $3.5/1M versus $15/1M. Input prices and retry rates still move the real bill.

Which is faster, Claude Sonnet 4.5 or Llama 3.1 405B?

Claude Sonnet 4.5 has the lower time-to-first-token (240 ms vs 360 ms). Tokens/sec is a separate column if you care about long completions.

Which has the larger context window?

Claude Sonnet 4.5 accepts 1M tokens versus 128k.

Can I self-host either model?

Llama 3.1 405B is marked open-weights in our catalog. The other side is a closed API. Check the provider license before you ship weights.

Are these scores from CompareLLM’s own evals?

No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.

What does preference Elo mean on this page?

Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. Claude Sonnet 4.5 and Llama 3.1 405B Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

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Interactive Comparison Diagram

Tug-of-War Matchup Matrix

Intelligence & Reasoning

Speed & Latency

Pricing & Capacity

Multi-Dimensional Capability Radar

Claude Sonnet 4.5

Claude Sonnet 4.5

Llama 3.1 405B

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

Claude Sonnet 4.5 is the previous workhorse — still a valid vs baseline

Cast Your Matchup Vote

Community Discussions (0)

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CompareLLM Matrix

Claude Sonnet 4.5

Llama 3.1 405B

Frequently Asked Questions

Related news

Similar Head-to-Head Comparisons

Swap or Add Any Model to this Matchup

Interactive Comparison Diagram

Tug-of-War Matchup Matrix

Intelligence & Reasoning

Speed & Latency

Pricing & Capacity

Multi-Dimensional Capability Radar

Claude Sonnet 4.5

Claude Sonnet 4.5

Llama 3.1 405B

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

Claude Sonnet 4.5 is the previous workhorse — still a valid vs baseline

Cast Your Matchup Vote

Community Discussions (0)

Share card

CompareLLM Matrix

Claude Sonnet 4.5

Llama 3.1 405B

Frequently Asked Questions

Related news

Similar Head-to-Head Comparisons