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-5.1 outperforms gpt-4.1 on 9 of 9 shared benchmarks.
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
Benchmark comparison
MMLU Proknowledge
gpt-4.185.3%
gpt-5.189.4%
GPQA Diamondreasoning
gpt-4.174.1%
gpt-5.183.2%
HumanEvalcoding
gpt-4.191.8%
gpt-5.194.7%
SWE-Bench Verifiedcoding
gpt-4.168.1%
gpt-5.176.8%
MATHmath
gpt-4.189.2%
gpt-5.194.8%
AIME 2024math
gpt-4.172.4%
gpt-5.190.1%
MMMUmultimodal
gpt-4.174.8%
gpt-5.180.3%
LiveBenchreasoning
gpt-4.166.7%
gpt-5.176.2%
τ-bench Retailagentic
gpt-4.165.1%
gpt-5.173.5%
Scores sourced from official model cards, Artificial Analysis, and public leaderboards. Benchmarks measure specific skills and don't capture every aspect of model quality.
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 | — | Yes |
| Prompt caching | Yes | Yes |
| Computer use | — | — |
| Provider | OpenAI Inc. | OpenAI Inc. |
Questions people ask
Is gpt-4.1 better than gpt-5.1?
gpt-5.1 outperforms gpt-4.1 on 9 of 9 shared benchmarks. See the benchmark comparison above for specifics — gpt-4.1 and gpt-5.1 have different strengths across reasoning, coding, math and multimodal tasks.
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 — "openai/gpt-4.1" or "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 400+ models. Change the model parameter, not your code.
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