OpenAI: GPT-5.1
by OpenAIOpenAI: GPT-5.1 is a large language model from OpenAI. It costs $1.25 per million input tokens and $10.00 per million output tokens. Its context window is 400K tokens.
- Input / 1M tokens
- $1.25
- Output / 1M tokens
- $10.00
- Cached input / 1M
- $0.125
- Context window
- 400K
On repeated prefixes
tokens
This model also charges $0.01 per search request
That is $10.00 per 1,000 requests, billed on top of the token prices above. On a typical 1,000-in / 500-out exchange the tokens cost $0.0063, so the search fee is 1.6× the token cost. Per-token rankings elsewhere ignore this entirely.
Who serves it cheapest
2 hosts serve GPT-5.1. Same weights, same API - the price difference is pure margin and routing.
| Provider | Input / 1M | Output / 1M | Context | Throughput | Uptime 24h |
|---|---|---|---|---|---|
| OpenAICheapest | $0.625 | $5.00 | 400K | - | 100.0% |
| Azure | $1.25 | $10.00 | 400K | - | 100.0% |
The spread between OpenAI and Azure is 2.0× for identical weights. Quantization and context limits differ, so check both columns before switching.
Benchmarks
Independent scores published alongside the catalogue.
- Coding index
- 49.4
About GPT-5.1
GPT-5.1 is the latest frontier-grade model in the GPT-5 series, offering stronger general-purpose reasoning, improved instruction adherence, and a more natural conversational style compared to GPT-5. It uses adaptive reasoning...
Specifications
| Model ID | openai/gpt-5.1 |
|---|---|
| Provider | OpenAI |
| Context window | 400K tokens |
| Max output | 128K tokens |
| Input modalities | image, text, file |
| Output modalities | text |
| Knowledge cutoff | - |
| Open weights | No |
| Released | November 13, 2025 |
Cheaper alternatives
Models that cost less than GPT-5.1 while keeping at least half its context window and every input modality it supports.
Frequently asked
How much does OpenAI: GPT-5.1 cost?
$1.25 per million input tokens and $10.00 per million output tokens. Cached input reads cost $0.125 per million tokens.
What is the context window of OpenAI: GPT-5.1?
400K tokens, with up to 128K tokens of output per request.
Does OpenAI: GPT-5.1 have extra fees beyond per-token pricing?
Yes. OpenAI: GPT-5.1 charges $0.01 per search request - $10.00 per 1,000 requests - on top of $1.25 per million input tokens and $10.00 per million output tokens. On a typical 1,000-input / 500-output exchange the search fee alone is 1.6× the token cost.
Which provider serves OpenAI: GPT-5.1 cheapest?
OpenAI at $0.625 per million input tokens - 2.0× cheaper than Azure, the most expensive of the 2 hosts serving it.
Confirm against the source: OpenAI official pricing.