Data points: 81
Model compare
The readout for GPT-3.5 Turbo and GPT-5.1, before the detailed comparison sheet.
Weighted outcome: GPT-5.1. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Decision read
GPT-5.1
GPT-5.1 has the higher weighted result; Model A / B score 8 to 92.
Evidence depth
81 data points
Includes 8 benchmark rows, 0 audit samples, and 6 provider examples.
Selection signal
Start with GPT-5.1
The charts below split 14 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 GPT-3.5 Turbo and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Model compare | GPT-3.5 Turbo | GPT-5.1 |
|---|---|---|
| Overall leader | Contender | Leading |
| Weighted overall score | 8.0 pts | 92.0 pts |
| Benchmark category leads | 0 categories | 3 categories |
| Operational advantages | First-token latency, Free providers | Cheapest input price, Average speed, Provider coverage |
| Context window | 16.4K tokens | 400K tokens |
| Max output | 4.1K tokens | 128K tokens |
| Modalities | Input Text Output Text | Input Image |
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 | GPT-3.5 Turbo | GPT-5.1 |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Released | Jan 2024 | Nov 2025 |
| Parameters | No data | No data |
| Tokenizer | GPT | GPT |
| Knowledge cutoff | 2021-09-30 | No data |
| OpenRouter ID | openai/gpt-3.5-turbo | openai/gpt-5.1 |
| References | No data | No data |
This report only uses LMSpeed data for GPT-3.5 Turbo and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
GPT-3.5 Turbo
GPT-3.5 Turbo has these operational advantages: First-token latency, Free providers.
GPT-5.1
GPT-5.1 is stronger in benchmark categories (Coding, Reasoning, Math) and operational dimensions (Cheapest input price, Average speed, 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
GPT-3.5 Turbo
40
Avg. score
GPT-5.1
55.5
GPT-5.1
GPT-5.1 leads by 3.4
GPT-5.1 leads by 19.0
GPT-5.1
GPT-5.1 leads by 16.7
GPT-5.1
GPT-5.1
GPT-5.1
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
GPT-3.5 Turbo
winner0.70 s
Rank #25/139 · confidence 4
GPT-5.1
30.09 s
Rank #103/139 · confidence 4
GPT-3.5 Turbo
winner0.70 s
Rank #34/139 · confidence 4
GPT-5.1
30.09 s
Rank #127/139 · confidence 4
GPT-3.5 Turbo
winner138.2 tok/s
Rank #39/139 · confidence 4
GPT-5.1
109.7 tok/s
Rank #55/139 · confidence 4
GPT-3.5 Turbo
winner$1.50/M
Rank #54/163 · confidence 4
GPT-5.1
$10.00/M
Rank #122/163 · confidence 4
GPT-3.5 Turbo
winner$0.750/M
Rank #60/163 · confidence 4
GPT-5.1
$3.44/M
Rank #119/163 · confidence 4
GPT-3.5 Turbo
winner$0.500/M
Rank #70/163 · confidence 4
GPT-5.1
$1.25/M
Rank #109/163 · confidence 4
GPT-3.5 Turbo
46.2%
Rank #124/125 · confidence 4
GPT-5.1
winner87.0%
Rank #12/125 · confidence 4
GPT-3.5 Turbo
29.7%
Rank #186/187 · confidence 4
GPT-5.1
winner87.3%
Rank #32/187 · confidence 4
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | GPT-3.5 Turbo | GPT-5.1 |
|---|---|---|
| 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 | GPT-3.5 Turbo | GPT-5.1 |
|---|---|---|
10 tests | GPT-3.5 Turbo speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency 137 tok/s / 3299ms input / output No data |
5 tests | GPT-3.5 Turbo speed / latency 54 tok/s / 9591ms input / output No data | GPT-5.1 speed / latency N/A / N/A input / output No data |
5 tests | GPT-3.5 Turbo speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency 96 tok/s / 1862ms input / output No data |
2 tests | GPT-3.5 Turbo speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency 139 tok/s / 1654ms input / output No data |
0 tests | GPT-3.5 Turbo speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency N/A / N/A input / output No data |
GPT-3.5 Turbo gpt-3.5-turbo-16k speed / latency No data input / output $0/request | GPT-5.1 gpt-5.1 speed / latency No data input / output $0/request |
Weighted outcome: GPT-5.1. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Output
| Features | Text inputText outputTool callingStructured outputsJSON mode | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
|---|
