Compare / GPT-4.1 Nano vs GPT-5.1
GPT-4.1 Nano vs GPT-5.1
Which is cheaper, which is more capable, and which does better at each kind of work, from 17 results on 3 sources that measured both models.
GPT-4.1 Nano or GPT-5.1? The short answer
- GPT-4.1 Nano is cheaper: $0.18 against $3.44 per million tokens, 20 times less.
- GPT-5.1 scores higher on the Artificial Analysis Intelligence Index: 24.7 against 7.8.
- On our business benchmarks, GPT-5.1 ranks higher for agents and tool use, reasoning and knowledge, writing and sticking to the facts.
At a glance
| GPT-4.1 Nano | GPT-5.1 | |
|---|---|---|
| Price per million tokens | $0.10 in · $0.40 out | $1.25 in · $10.00 out |
| Blended (3 in : 1 out) | $0.18 | $3.44 |
| Cheapest host, blended | $0.18 (Azure) | $1.72 (OpenAI) |
| Intelligence Index | 7.8 | 24.7 |
| Spring Prompt overall | – | – |
| Output speed, tokens a second | – | – |
| Context window | 1,047,576 tokens | 400,000 tokens |
| Weights | Closed | Closed |
| Developer based in | the US | the US |
Prices are the developer's list price where we have read it, otherwise the typical host on OpenRouter; see every model's price. Intelligence and speed from Artificial Analysis.
Which is better for what
Each model's rank among models available today, for each kind of work, from our own benchmarks and licensed sources. The better rank is in green.
| Use case | GPT-4.1 Nano | GPT-5.1 |
|---|---|---|
| Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls | 139 of 161 | 82 of 161 |
| Reasoning and knowledgeHard questions across science, maths and general knowledge | 169 of 195 | 66 of 195 |
| WritingWhat people prefer in blind comparisons, and judged writing quality | 162 of 187 | 52 of 187 |
| Sticking to the factsSummarising without inventing things, and factual answers | 151 of 153 | 62 of 153 |
Every shared result
| Benchmark | Metric | GPT-4.1 Nano | GPT-5.1 |
|---|---|---|---|
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,321 | 1,448 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,307 | 1,428 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,313 | 1,482 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,300 | 1,450 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,322 | 1,456 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,299 | 1,437 |
| Artificial Analysisreported | Artificial Analysis Coding Indexindex score | 11.1 | 49.4 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 7.80 | 24.7 |
| Artificial Analysisreported | GPQA Diamond% of questions | 51.2% | 87.3% |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 3.8% | 28.5% |
| Artificial Analysisreported | IFBench% of instructions | 32.0% | 72.9% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 20.3% | 80.0% |
| Artificial Analysisreported | Terminal-Bench 2.1% of tasks | 3.7% | 52.4% |
| Artificial Analysisreported | Terminal-Bench Hard% of tasks | 3.8% | 45.5% |
| Artificial Analysisreported | Τ-bench banking% of tasks | 3.5% | 15.9% |
| Artificial Analysisreported | Τ²-bench telecom% of tasks | 17.3% | 81.9% |
| SimpleQA Verified (Epoch AI)reported | Correct answers% of questions | 6.0% | 48.0% |
Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.
Quick answers
Is GPT-4.1 Nano better than GPT-5.1?
It depends on the task. Among models available today, on our benchmarks and licensed sources, GPT-5.1 ranks higher for agents and tool use, reasoning and knowledge, writing and sticking to the facts.
Which is cheaper, GPT-4.1 Nano or GPT-5.1?
GPT-4.1 Nano costs $0.18 per million tokens (three input to one output), against $3.44 for GPT-5.1.
Run GPT-4.1 Nano and GPT-5.1 on your own prompt
Benchmarks aren't your data. Try both side by side in the playground, with the cost of every answer.