Data points: 94
Model compare
The readout for Claude Sonnet 4 and Claude Sonnet 4.5, before the detailed comparison sheet.
Weighted outcome: Claude Sonnet 4.5. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Decision read
Claude Sonnet 4.5
Claude Sonnet 4.5 has the higher weighted result; Model A / B score 32 to 68.
Evidence depth
94 data points
Includes 14 benchmark rows, 0 audit samples, and 7 provider examples.
Selection signal
Start with Claude Sonnet 4.5
The charts below split 21 high-signal samples across speed, scores, and audit health.
Switch either side of this report to compare another model with the same LMSpeed data pipeline.
Select a different model to open a new comparison URL.
This report only uses LMSpeed data for Claude Sonnet 4 and Claude Sonnet 4.5: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Model compare | Claude Sonnet 4 | Claude Sonnet 4.5 |
|---|---|---|
| Overall leader | Contender | Leading |
| Weighted overall score | 32.0 pts | 68.0 pts |
| Benchmark category leads | 2 categories | 3 categories |
| Operational advantages | No data | Cheapest input price, Average speed, First-token latency, Free providers, Provider coverage |
| Context window | 1M tokens | 1M tokens |
| Max output | 64K tokens | 64K tokens |
| Modalities | Input ImageTextFile Output Text | Input |
The overall result weights benchmark capability categories at 80% and price, API speed/latency, and availability at 20%. Recent test volume does not affect the winner, and missing benchmark categories are excluded.
| Model compare | Claude Sonnet 4 | Claude Sonnet 4.5 |
|---|---|---|
| Developer | Anthropic | Anthropic |
| Released | May 2025 | Sep 2025 |
| Parameters | No data | No data |
| Tokenizer | Claude | Claude |
| Knowledge cutoff | 2025-01-31 | 2025-01-31 |
| OpenRouter ID | anthropic/claude-sonnet-4 | anthropic/claude-sonnet-4.5 |
| References | No data | No data |
This report only uses LMSpeed data for Claude Sonnet 4 and Claude Sonnet 4.5: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
Claude Sonnet 4
Claude Sonnet 4 leads these benchmark categories: Reasoning, Math.
Claude Sonnet 4.5
Claude Sonnet 4.5 is stronger in benchmark categories (Agents, Coding, Knowledge) and operational dimensions (Cheapest input price, Average speed, First-token latency, Free providers, Provider coverage).
Third-party benchmark profile synced into LMSpeed; only metrics available for both models are shown.
Compare benchmark category scores on a 0-100 scale. Select a category to inspect the gap.
Avg. score
Claude Sonnet 4
47.9
Avg. score
Claude Sonnet 4.5
48.3
Claude Sonnet 4.5 leads by 2.7
Claude Sonnet 4.5 leads by 5.5
Claude Sonnet 4 leads by 2.4
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
Claude Sonnet 4
winner56.0
Rank #41/84 · confidence 1 · eval date 2025-05-01
Claude Sonnet 4.5
47.0
Rank #64/84 · confidence 2 · eval date 2025-09-01
Claude Sonnet 4
$15.00/M
Rank #136/162 · confidence 4
Claude Sonnet 4.5
$15.00/M
Rank #136/162 · confidence 4
Claude Sonnet 4
$6.00/M
Rank #137/162 · confidence 4
Claude Sonnet 4.5
$6.00/M
Rank #137/162 · confidence 4
Claude Sonnet 4
$3.00/M
Rank #137/162 · confidence 4
Claude Sonnet 4.5
$3.00/M
Rank #137/162 · confidence 4
Claude Sonnet 4
83.7%
Rank #32/125 · confidence 4
Claude Sonnet 4.5
winner86.0%
Rank #20/125 · confidence 4
Claude Sonnet 4
68.3%
Rank #117/188 · confidence 4
Claude Sonnet 4.5
winner72.7%
Rank #107/188 · confidence 4
Claude Sonnet 4
4.0%
Rank #162/187 · confidence 4
Claude Sonnet 4.5
winner7.1%
Rank #112/187 · confidence 4
Claude Sonnet 4
72.7
Rank #33/43 · confidence 1 · eval date 2025-05-01
Claude Sonnet 4.5
winner77.2
Rank #20/43 · confidence 2 · eval date 2025-09-01
Claude Sonnet 4
48.4
Rank #44/65 · confidence 1 · eval date 2025-05-01
Claude Sonnet 4.5
winner54.7
Rank #28/65 · confidence 2 · eval date 2025-09-01
Claude Sonnet 4
37.3%
Rank #94/185 · confidence 4
Claude Sonnet 4.5
winner42.8%
Rank #44/185 · confidence 4
Claude Sonnet 4
44.9%
Rank #66/115 · confidence 4
Claude Sonnet 4.5
winner59.0%
Rank #45/115 · confidence 4
Claude Sonnet 4
1175.0
Rank #49/66 · confidence 1 · eval date 2025-05-01
Claude Sonnet 4.5
winner1219.0
Rank #38/66 · confidence 2 · eval date 2025-09-01
Claude Sonnet 4
18.4
Rank #15/20 · confidence 1 · eval date 2025-05-01
Claude Sonnet 4.5
winner27.7
Rank #10/20 · confidence 2 · eval date 2025-09-01
Claude Sonnet 4
39.7
Rank #38/50 · confidence 1 · eval date 2025-05-01
Claude Sonnet 4.5
winner48.5
Rank #26/50 · confidence 2 · eval date 2025-09-01
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | Claude Sonnet 4 | Claude Sonnet 4.5 |
|---|---|---|
| No completed audits are available from shared providers yet. | ||
Speed aggregates and input/output pricing share each provider row for real API selection and migration cost checks.
| Provider | Claude Sonnet 4 | Claude Sonnet 4.5 |
|---|---|---|
15 tests | Claude Sonnet 4 speed / latency N/A / N/A input / output No data | Claude Sonnet 4.5 speed / latency 46 tok/s / 5111ms input / output No data |
15 tests | Claude Sonnet 4 speed / latency 36 tok/s / 6227ms input / output No data | Claude Sonnet 4.5 speed / latency N/A / N/A input / output No data |
10 tests | Claude Sonnet 4 speed / latency 27 tok/s / 1036ms input / output No data | Claude Sonnet 4.5 speed / latency 21 tok/s / 1085ms input / output No data |
10 tests | Claude Sonnet 4 speed / latency N/A / N/A input / output No data | Claude Sonnet 4.5 speed / latency 41 tok/s / 3271ms input / output No data |
10 tests | Claude Sonnet 4 speed / latency N/A / N/A input / output No data | Claude Sonnet 4.5 speed / latency 45 tok/s / 3170ms input / output No data |
Claude Sonnet 4 claude-sonnet-4 speed / latency No data input / output $0/M/$0/M | Claude Sonnet 4.5 claude-sonnet-4-5 speed / latency No data input / output $0.247/M | |
Claude Sonnet 4 claude-sonnet-4-20250514 speed / latency No data input / output $0/request | Claude Sonnet 4.5 claude-sonnet-4-5-20250929 speed / latency No data input / output $0/request |
Weighted outcome: Claude Sonnet 4.5. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Output
| Features | Text inputImage inputFile inputText outputTool callingReasoning | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
|---|
Claude Sonnet 4.5 leads by 3.7
Claude Sonnet 4 leads by 10.5
No data
No data
Claude Sonnet 4
