GPT-5.1 Chat
retiredOpenAI · Multimodal · Released Nov 2025
OpenAI's fast, lightweight chat model from the GPT-5.1 family, optimized for low-latency inference while maintaining general-purpose reasoning capabilities.
- Strengths
- Delivers quick response times without sacrificing reasoning quality, with a 128k token context window suitable for processing longer documents and conversations.
- Best for
- Real-time chat applications, customer support systems, and other latency-sensitive workloads that still require reliable general reasoning.
- Limitations
- As the lightweight variant of the 5.1 family, it may underperform on highly complex reasoning tasks or specialized domains compared to larger models in the same family.
Input / 1M
$1.25
Output / 1M
$10.00
Cached input / 1M
$0.13
Context window
128K
Price history
Input (solid)Output (dashed)
Price change
- 30d
- in decreased 0.0% out decreased 0.0%
- 90d
- in decreased 0.0% out decreased 0.0%
- 1y
- in decreased 0.0% out decreased 0.0%
- Since launch
- in decreased 0.0% out decreased 0.0%
Snapshots
| Effective | Input | Output | Cached in | Note | Source |
|---|---|---|---|---|---|
| 27 Jul 2026 | $1.25 | $10.00 | $0.13 | Imported from OpenRouter | openrouter.ai |
| 15 Jul 2026 | $1.25 | $10.00 | $0.125 | Imported from OpenRouter | openrouter.ai |
| 11 Jun 2026 | $1.25 | $10.00 | $0.13 | Imported from OpenRouter | openrouter.ai |