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© 2026 CompareLLM. Public benchmark data aggregated from Arena Elo, LiveBench, SWE-bench & OpenRouter.

Every score has a dated snapshot.

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  2. Comparisons
  3. Claude Sonnet 4 vs Claude Sonnet 4.5

Pairwise benchmark snapshot · Aug 1, 2026

Claude Sonnet 4 vs Claude Sonnet 4.5 benchmark

In this head-to-head showdown, Claude Sonnet 4.5 delivers higher overall intelligence and human-preferred responses (Elo 1,524 vs 1,455), while Claude Sonnet 4.5 leads in SWE-bench software engineering benchmarks (70.1%), while Claude Sonnet 4 is more budget-friendly at $15/1M per 1M output tokens. Review the complete breakdown below to determine which model best fits your performance and budget requirements.

Executive Comparison Verdict

Bottom Line: Choose Claude Sonnet 4.5 if your priority is peak reasoning, complex code generation, and top preference Elo. Choose Claude Sonnet 4 if you are optimizing for low latency, high throughput, and cost-efficient API deployment.
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Verified Head-to-Head Advantage Breakdown

7 direct benchmark disciplines evaluated across capability, speed, and cost

Claude Sonnet 4 (2)Claude Sonnet 4.5 (5)
Claude Sonnet 4
2 of 7 Wins
✓Time to first token✓Output speed
Claude Sonnet 4.5
5 of 7 Wins
✓Preference Elo✓Coding Elo✓LiveBench✓SWE-bench✓GPQA Diamond
Anthropic
Leads 2 of 7 metrics
Claude Sonnet 4

First Sonnet 4 generation. Bridge between 3.5/3.7 and Sonnet 5.

Elo 1,455$15/1M out
Anthropic
Leads 5 of 7 metrics
Claude Sonnet 4.5

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

Sonnet 4.5Elo 1,524$15/1M out
Top Rival Showdowns for Claude Sonnet 4
All Matchups
Compare vs:vs GPT-5vs Gemini 3 Provs Grok 4.6vs DeepSeek V4 Provs Qwen 3 Max
Preference LeaderClaude Sonnet 4.5 Wins

Claude Sonnet 4.5

Δ 69 Arena Elo pts

Throughput LeaderClaude Sonnet 4 Wins

Claude Sonnet 4

92 tok/s

Value per Dollar LeaderClaude Sonnet 4 Wins

Claude Sonnet 4

$15 / 1M output

Capability Percentiles

Relative percentile scores computed across all active models in the benchmark catalog.

Multi-Dimensional Capability Radar

Leaders Matchup Capability Radar

Comparing top Western standard models with China's leading frontier rival across 6 skill dimensions. Tap any spoke or dot to inspect.

Tap any node to inspect
Percentile 0–100
Head-to-Head Comparison

Overall Matchup Breakdown

Category wins across reasoning intelligence, generation speed, and token cost.

Claude Sonnet 4 (2)vsClaude Sonnet 4.5 (5)
Claude Sonnet 4: 2W (29%)Overall: Claude Sonnet 4.5Claude Sonnet 4.5: 5W (71%)
← Claude Sonnet 43 tiesClaude Sonnet 4.5 →
🏆Claude Sonnet 4.5(5/5)

Intelligence & Reasoning

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

Benchmark
Claude Sonnet 4vsClaude Sonnet 4.5
Preference Elo
1,455vs1,524+69
Coding Elo
1,468vs1,531+63
SWE-bench
62.8%vs70.1%+7.3%
LiveBench
63.2%vs67.4%+4.2%
GPQA Diamond
76.4%vs80.2%+3.8%
Claude Sonnet 4: 0WClaude Sonnet 4.5: 5W
🏆Claude Sonnet 4(2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Benchmark
Claude Sonnet 4vsClaude Sonnet 4.5
Output speed
92 tok/svs88 tok/s+4 tok/s
Time to first token
220 msvs240 ms+20 ms
Claude Sonnet 4: 2WClaude Sonnet 4.5: 0W
Tied (0-0)

Pricing & Capacity

Cost per million tokens and max context window length

Benchmark
Claude Sonnet 4vsClaude Sonnet 4.5
Output price
$15/1Mvs$15/1M
Input price
$3/1Mvs$3/1M
Context window
200kvs200k
Claude Sonnet 4: 0WClaude Sonnet 4.5: 0W

Side-by-Side Benchmark Matrix

Preference Elo+69
Claude Sonnet 41,455
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.51,524
seed-bootstrap · Aug 1, 2026
Coding Elo+63
Claude Sonnet 41,468
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.51,531
seed-bootstrap · Aug 1, 2026
LiveBench+4.2%
Claude Sonnet 463.2%
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.567.4%
seed-bootstrap · Aug 1, 2026
SWE-bench+7.3%
Claude Sonnet 462.8%
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.570.1%
seed-bootstrap · Aug 1, 2026
GPQA Diamond+3.8%
Claude Sonnet 476.4%
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.580.2%
seed-bootstrap · Aug 1, 2026
Time to first token+20 ms
Claude Sonnet 4220 ms
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.5240 ms
seed-bootstrap · Aug 1, 2026
Output speed+4 tok/s
Claude Sonnet 492 tok/s
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.588 tok/s
seed-bootstrap · Aug 1, 2026
Input price
Claude Sonnet 4$3/1M
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.5$3/1M
seed-bootstrap · Aug 1, 2026
Output price
Claude Sonnet 4$15/1M
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.5$15/1M
seed-bootstrap · Aug 1, 2026
Context window
Claude Sonnet 4200k
seed-bootstrap · Aug 1, 2026
Claude Sonnet 4.5200k
seed-bootstrap · Aug 1, 2026
BenchmarkClaude Sonnet 4Claude Sonnet 4.5Advantage Delta
Preference Elo
1,455
seed-bootstrap · Aug 1, 2026
1,524
seed-bootstrap · Aug 1, 2026
+69
Coding Elo
1,468
seed-bootstrap · Aug 1, 2026
1,531
seed-bootstrap · Aug 1, 2026
+63
LiveBench
63.2%
seed-bootstrap · Aug 1, 2026
67.4%
seed-bootstrap · Aug 1, 2026
+4.2%
SWE-bench
62.8%
seed-bootstrap · Aug 1, 2026
70.1%
seed-bootstrap · Aug 1, 2026
+7.3%
GPQA Diamond
76.4%
seed-bootstrap · Aug 1, 2026
80.2%
seed-bootstrap · Aug 1, 2026
+3.8%
Time to first token
220 ms
seed-bootstrap · Aug 1, 2026
240 ms
seed-bootstrap · Aug 1, 2026
+20 ms
Output speed
92 tok/s
seed-bootstrap · Aug 1, 2026
88 tok/s
seed-bootstrap · Aug 1, 2026
+4 tok/s
Input price
$3/1M
seed-bootstrap · Aug 1, 2026
$3/1M
seed-bootstrap · Aug 1, 2026
—
Output price
$15/1M
seed-bootstrap · Aug 1, 2026
$15/1M
seed-bootstrap · Aug 1, 2026
—
Context window
200k
seed-bootstrap · Aug 1, 2026
200k
seed-bootstrap · Aug 1, 2026
—
Interactive Simulator (USD)

Workload Cost & Savings Calculator

Simulate monthly production API costs in USD (US Dollar).

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$330.00 / mo
In: $105Out: $225
Claude Sonnet 4.5$330.00 / mo
In: $105Out: $225

Key Selection Recommendations

  • 1
    Claude Sonnet 4.5:Pick Claude Sonnet 4.5 when repo-level coding accuracy is the constraint.
  • 2
    Claude Sonnet 4:Pick Claude Sonnet 4 when you are optimizing output cost.
  • 3
    Claude Sonnet 4:Pick Claude Sonnet 4 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 chatClaude Sonnet 4

Lower output list price ($15/1M).

Voice / low-latency UIClaude Sonnet 4

Lower TTFT (220 ms).

Long-document RAGClaude Sonnet 4

Larger window (200k).

Screenshots / visionClaude Sonnet 4.5

Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).

Target WorkloadRecommended PickEvaluation Rationale
Repo / coding agentsClaude Sonnet 4.5Higher SWE-bench (70.1%).
High-volume chatClaude Sonnet 4Lower output list price ($15/1M).
Voice / low-latency UIClaude Sonnet 4Lower TTFT (220 ms).
Long-document RAGClaude Sonnet 4Larger window (200k).
Screenshots / visionClaude Sonnet 4.5Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).

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.

Community Sentiment

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CompareLLM AI Matrix

Verified Head-to-Head Telemetry

LIVE BENCHMARK
VS
Anthropic

Claude Sonnet 4

Elo 1,455
SWE-bench62.8%
Speed (tok/s)92 tok/s
Input / 1M Tokens$3/1M
Output / 1M Tokens$15/1M
Anthropic

Claude Sonnet 4.5

Elo 1,524
SWE-bench70.1%
Speed (tok/s)88 tok/s
Input / 1M Tokens$3/1M
Output / 1M Tokens$15/1M

Frequently Asked Questions

Which is better overall, Claude Sonnet 4 or Claude Sonnet 4.5?
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 or Claude Sonnet 4.5?
Claude Sonnet 4.5 leads SWE-bench at 70.1% vs 62.8%. SWE-bench is one harness, not your repo.
Which is cheaper to run in production?
Claude Sonnet 4 output tokens are $15/1M versus $15/1M. Input prices and retry rates still move the real bill.
Which is faster, Claude Sonnet 4 or Claude Sonnet 4.5?
Claude Sonnet 4 has the lower time-to-first-token (220 ms vs 240 ms). Tokens/sec is a separate column if you care about long completions.
Which has the larger context window?
Claude Sonnet 4 accepts 200k tokens versus 200k.
Can I self-host either model?
Neither model is marked open-weights here. You are comparing hosted APIs.
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 and Claude Sonnet 4.5 Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Related news

  • launch · Feb 18, 2026

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

Similar Head-to-Head Comparisons

All Claude Sonnet 4 matchups →|All Claude Sonnet 4.5 matchups →
Claude Sonnet 4 vs Claude 3.7 Sonnet (previous sonnet)Claude Sonnet 4.5 vs Claude Sonnet 5 (next sonnet)Claude Opus 4.5 vs Claude Sonnet 4.5Claude Opus 4.6 vs Claude Sonnet 4.5Claude Opus 4.8 vs Claude Sonnet 4.5Claude Opus 5 vs Claude Sonnet 4.5