GPT-5.1
by OpenAI · openai/gpt-5.1 · #245 cheapest of 325 paid models
Prices updated Jul 22, 2026, 1:31 AM UTC · refreshed hourly
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...
Compare vs:Claude Sonnet 5Claude Opus 4.6Claude Haiku 4.5Gemini 3.6 Flash
Pricing
Input
$1.25
per 1M tokens
Output
$10.00
per 1M tokens
Blended (3:1)
$3.44
3 input : 1 output
Cache read
$0.125
per 1M cached tokens
Cache write
—
per 1M tokens
Cache & batch economics
Effective prices for GPT-5.1 with prompt caching.
| Cache hit rate | Effective blended $/1M | Example request* | vs no cache |
|---|---|---|---|
| 0% | $3.44 | $0.1375 | — |
| 50% | $3.02 | $0.0813 | −41% |
| 90% | $2.68 | $0.0362 | −74% |
*Example: 100K sticky context + 2K new input + 1K output. Batch discount is an approximate 50% off list rates for this provider’s batch API. Confirm on the vendor’s pricing page.
What a request costs
| Workload | Input tokens | Output tokens | Cost / request | Cost / 1K requests |
|---|---|---|---|---|
| Short chat message | 500 | 300 | $0.003625 | $3.62 |
| Document summary | 8,000 | 1,000 | $0.02 | $20.00 |
| Codebase question (RAG) | 30,000 | 2,000 | $0.0575 | $57.50 |
| Long-context analysis | 150,000 | 5,000 | $0.2375 | $237.50 |
Performance
Intelligence Index
36.9
AA composite quality
Coding Index
49.4
Math Index
94
Agentic Index
21
Output speed
110 tok/s
median
Time to first token
39.50s
median
Time to first answer
39.50s
after reasoning tokens
Artificial Analysis benchmarks
| Benchmark | Score |
|---|---|
| MMLU-Pro | 87.0% |
| GPQA Diamond | 87.3% |
| Humanity's Last Exam | 26.5% |
| LiveCodeBench | 86.8% |
| SciCode | 43.3% |
| AIME 2025 | 94.0% |
| IFBench | 72.9% |
| AA-LCR (Long Context Reasoning) | 75.0% |
| Terminal-Bench Hard | 45.5% |
| Terminal-Bench 2.1 | 52.4% |
| τ²-Bench (Telecom) | 81.9% |
| τ³-Bench Banking | 14.0% |
Design Arena Elo
| Category | Elo |
|---|---|
| Website | 1,215 |
| Web apps | 1,075 |
| Mobile apps | 1,122 |
| UI components | 1,209 |
| Data viz | 1,241 |
| SVG | 1,196 |
| 3D | 1,120 |
| Game dev | 1,237 |
| Code categories | 1,204 |
| ASCII art | 1,160 |
Specs
Context window
400K
tokens
Max output
128K
tokens
Input modalities
image, text, file
Tokenizer
GPT