gpt-4.1 vs gpt-5.1
Side-by-side comparison of gpt-4.1 and gpt-5.1: benchmarks, pricing, context window and capabilities. Both are accessible through Requesty's unified API.
gpt-4.1
Input / 1M
$2.00
Output / 1M
$8.00
Context
1.0M
Model ID
openai/gpt-4.1
gpt-5.1
Input / 1M
$1.25
Output / 1M
$10.00
Context
400K
Model ID
openai/gpt-5.1
Pricing & specifications
| gpt-4.1 | gpt-5.1 | |
|---|---|---|
| Input price / 1M | $2.00 | $1.25 |
| Output price / 1M | $8.00 | $10.00 |
| Context window | 1.0M tokens | 400K tokens |
| Max output | 33K tokens | 128K tokens |
| Vision input | Yes | Yes |
| Tool calling | Yes | Yes |
| Reasoning | N/A | Yes |
| Prompt caching | Yes | Yes |
| Computer use | N/A | N/A |
| Provider | OpenAI | OpenAI |
Questions people ask
Is gpt-4.1 better than gpt-5.1?
Benchmark data is limited for one or both models. Compare pricing and capabilities in the tables above, and test both on your own workload.
Which is cheaper, gpt-4.1 or gpt-5.1?
gpt-4.1 is cheaper. gpt-4.1 costs $2.00/$8.00 per 1M input/output tokens, while gpt-5.1 costs $1.25/$10.00.
Can I use gpt-4.1 and gpt-5.1 through the same API?
Yes. Requesty provides a single OpenAI-compatible API that routes to both. Change just the "model" parameter to switch between "openai/gpt-4.1" and "openai/gpt-5.1", no other code changes needed.
What are the context windows?
gpt-4.1 supports up to 1.0M tokens of context. gpt-5.1 supports up to 400K tokens. Longer context means you can feed larger documents or codebases in a single prompt, though quality often degrades past 128K for most models.
Switch between gpt-4.1 and gpt-5.1 with one line of code
Requesty provides a single OpenAI-compatible API for 600+ models. Change the model parameter, not your code.