Data points: 62
Model compare
The readout for Gemini 3.1 Flash TTS Preview 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 0 to 100.
Evidence depth
62 data points
Includes 0 benchmark rows, 0 audit samples, and 8 provider examples.
Selection signal
Start with GPT-5.1
The charts below split 8 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 Gemini 3.1 Flash TTS Preview and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Model compare | Gemini 3.1 Flash TTS Preview | GPT-5.1 |
|---|---|---|
| Overall leader | Contender | Leading |
| Weighted overall score | 0.0 pts | 100.0 pts |
| Benchmark category leads | 0 categories | 0 categories |
| Operational advantages | No data | Cheapest input price, Free providers, Provider coverage |
| Context window | 32.8K tokens | 400K tokens |
| Max output | 16.4K tokens | 128K tokens |
| Modalities | Input Text Output speech | 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 | Gemini 3.1 Flash TTS Preview | GPT-5.1 |
|---|---|---|
| Developer | OpenAI | |
| Released | Apr 2026 | Nov 2025 |
| Parameters | No data | No data |
| Tokenizer | Gemini | GPT |
| Knowledge cutoff | No data | No data |
| OpenRouter ID | google/gemini-3.1-flash-tts-preview | openai/gpt-5.1 |
| References | No data | No data |
This report only uses LMSpeed data for Gemini 3.1 Flash TTS Preview and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
Gemini 3.1 Flash TTS Preview
Gemini 3.1 Flash TTS Preview does not clearly lead in the benchmark or operational dimensions shared by both models.
GPT-5.1
GPT-5.1 has these operational advantages: Cheapest input price, 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
Gemini 3.1 Flash TTS Preview
-
Avg. score
GPT-5.1
52
GPT-5.1
GPT-5.1
GPT-5.1
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
No shared professional benchmark scores are available yet.
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | Gemini 3.1 Flash TTS Preview | 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 | Gemini 3.1 Flash TTS Preview | GPT-5.1 |
|---|---|---|
0 tests | Gemini 3.1 Flash TTS Preview speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency N/A / N/A input / output No data |
0 tests | Gemini 3.1 Flash TTS Preview speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency N/A / N/A input / output No data |
0 tests | Gemini 3.1 Flash TTS Preview gemini-3.1-flash-tts-preview speed / latency N/A / N/A input / output $0.127/M/$2.55/M | GPT-5.1 gpt-5.1 speed / latency N/A / N/A input / output $1.59/M |
0 tests | Gemini 3.1 Flash TTS Preview speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency N/A / N/A input / output No data |
0 tests | Gemini 3.1 Flash TTS Preview speed / latency N/A / N/A input / output No data | GPT-5.1 speed / latency N/A / N/A input / output No data |
Gemini 3.1 Flash TTS Preview gemini-3.1-flash-tts-preview speed / latency No data input / output $0/request | GPT-5.1 gpt-5.1-all speed / latency No data input / output $0/request | |
Gemini 3.1 Flash TTS Preview gemini-3.1-flash-tts-preview speed / latency No data input / output $0.068/M/$1.37/M | GPT-5.1 gpt-5.1-chat-latest speed / latency No data input / output $0.856/M | |
Gemini 3.1 Flash TTS Preview gemini-3.1-flash-tts-preview speed / latency No data input / output $0.110/M/$2.19/M | GPT-5.1 gpt-5.1-chat-latest speed / latency No data input / output $1.37/M |
Weighted outcome: GPT-5.1. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Output
| Features | Text inputSpeech outputJSON mode | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
|---|
GPT-5.1
GPT-5.1
No data
No data
GPT-5.1
