Data points: 79
Model compare
The readout for Claude Sonnet 4.6 and GPT-5.5 Pro, before the detailed comparison sheet.
Weighted outcome: GPT-5.5 Pro. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Decision read
GPT-5.5 Pro
GPT-5.5 Pro has the higher weighted result; Model A / B score 40 to 60.
Evidence depth
79 data points
Includes 8 benchmark rows, 0 audit samples, and 7 provider examples.
Selection signal
Start with GPT-5.5 Pro
The charts below split 15 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 4.6 and GPT-5.5 Pro: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Model compare | Claude Sonnet 4.6 | GPT-5.5 Pro |
|---|---|---|
| Overall leader | Contender | Leading |
| Weighted overall score | 40.0 pts | 60.0 pts |
| Benchmark category leads | 1 categories | 3 categories |
| Operational advantages | Cheapest input price, Free providers, Provider coverage | No data |
| Context window | 1M tokens | 1.1M tokens |
| Max output | 128K tokens | 128K tokens |
| Modalities | Input TextImageFile Output Text |
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 4.6 | GPT-5.5 Pro |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Released | Feb 2026 | Apr 2026 |
| Parameters | No data | No data |
| Tokenizer | Claude | GPT |
| Knowledge cutoff | No data | 2025-12-01 |
| OpenRouter ID | anthropic/claude-sonnet-4.6 | openai/gpt-5.5-pro |
| References | No data | No data |
This report only uses LMSpeed data for Claude Sonnet 4.6 and GPT-5.5 Pro: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
Claude Sonnet 4.6
Claude Sonnet 4.6 is stronger in benchmark categories (Knowledge) and operational dimensions (Cheapest input price, Free providers, Provider coverage).
GPT-5.5 Pro
GPT-5.5 Pro leads these benchmark categories: Agents, Reasoning, Math.
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 4.6
53.1
Avg. score
GPT-5.5 Pro
60.7
GPT-5.5 Pro leads by 8.2
Claude Sonnet 4.6
GPT-5.5 Pro leads by 13.1
Claude Sonnet 4.6 leads by 9.6
GPT-5.5 Pro leads by 4.0
No data
Claude Sonnet 4.6
Claude Sonnet 4.6
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
Claude Sonnet 4.6
62.0
Rank #30/93 · confidence 3 · eval date 2026-02-01
GPT-5.5 Pro
winner76.0
Rank #10/93 · confidence 1 · eval date 2026-04-23
Claude Sonnet 4.6
0.9
Rank #65/78 · confidence 3 · eval date 2026-02-01
GPT-5.5 Pro
winner30.6
Rank #2/78 · confidence 1 · eval date 2026-04-23
Claude Sonnet 4.6
33.6%
Rank #36/199 · confidence 4
GPT-5.5 Pro
winner57.2%
Rank #2/199 · confidence 1 · eval date 2026-04-23
Claude Sonnet 4.6
8.3
Rank #19/35 · confidence 3 · eval date 2026-02-01
GPT-5.5 Pro
winner39.6
Rank #4/35 · confidence 1 · eval date 2026-04-23
Claude Sonnet 4.6
32.4
Rank #18/47 · confidence 3 · eval date 2026-02-01
GPT-5.5 Pro
winner51.0
Rank #5/47 · confidence 1 · eval date 2026-04-23
Claude Sonnet 4.6
49.5
Rank #34/59 · confidence 3 · eval date 2026-02-01
GPT-5.5 Pro
winner72.1
Rank #15/59 · confidence 1 · eval date 2026-04-23
Claude Sonnet 4.6
76.9
Rank #20/64 · confidence 3 · eval date 2026-02-01
GPT-5.5 Pro
winner85.6
Rank #6/64 · confidence 1 · eval date 2026-04-23
Claude Sonnet 4.6
54.2
Rank #37/62 · confidence 3 · eval date 2026-02-01
GPT-5.5 Pro
winner83.2
Rank #12/62 · confidence 1 · eval date 2026-04-23
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | Claude Sonnet 4.6 | GPT-5.5 Pro |
|---|---|---|
| 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 4.6 | GPT-5.5 Pro |
|---|---|---|
10 tests | Claude Sonnet 4.6 speed / latency 48 tok/s / 1587ms input / output No data | GPT-5.5 Pro speed / latency N/A / N/A input / output No data |
5 tests | Claude Sonnet 4.6 speed / latency 55 tok/s / 2094ms input / output No data | GPT-5.5 Pro speed / latency N/A / N/A input / output No data |
5 tests | Claude Sonnet 4.6 speed / latency 20 tok/s / 8427ms input / output No data | GPT-5.5 Pro speed / latency N/A / N/A input / output No data |
0 tests | Claude Sonnet 4.6 speed / latency N/A / N/A input / output No data | GPT-5.5 Pro speed / latency N/A / N/A input / output No data |
0 tests | Claude Sonnet 4.6 speed / latency N/A / N/A input / output No data | GPT-5.5 Pro speed / latency N/A / N/A input / output No data |
Claude Sonnet 4.6 claude-sonnet-4-6 speed / latency No data input / output $0/request | GPT-5.5 Pro gpt-5.5-pro speed / latency No data input / output $0/request | |
Claude Sonnet 4.6 claude-sonnet-4-6-c speed / latency No data input / output $0.0082/request | GPT-5.5 Pro gpt-5.5-pro speed / latency No data input / output $69.86/M |
Weighted outcome: GPT-5.5 Pro. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Input
Output
| Features | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
|---|
