GPT-4.1 vs GPT-5.1
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Quick verdict: which should you choose?
Choose GPT-4.1 if you need
- ✓Choose GPT-5.1 if you need the highest intelligence_index of 27.4 for complex multimodal reasoning.
- ✓Choose GPT-5.1 if you need strong native integration of images, text, and files in a single workflow.
- ✓Choose GPT-5.1 if you need a very large 400k context window without exceeding typical usage limits.
- ✓Choose GPT-5.1 if you need optimized performance for verified multimodal tasks over raw speed.
Choose GPT-5.1 if you need
- ✓Choose GPT-4.1 if you need the fastest output at 129.94 t/s for high-volume generation.
- ✓Choose GPT-4.1 if you need the lower price of $8 per million tokens for cost-sensitive workloads.
- ✓Choose GPT-4.1 if you need the largest context window exceeding 1 million tokens.
- ✓Choose GPT-4.1 if you need flexible multimodal inputs with strong GPT-lineage reasoning at scale.
Verdict
GPT-5.1 leads with a higher intelligence_index of 27.4 versus 26.3, offering stronger multimodal integration for image-text-file tasks within its 400k context. GPT-4.1 counters with superior speed at 129.94 t/s, lower price of $8/1M tokens, and over 1M context tokens for larger-scale processing. The choice hinges on whether raw intelligence or efficiency and scale matter most.
GPT-4.1 vs GPT-5.1: side by side
| Spec | GPT-4.1 | GPT-5.1 | Winner |
|---|---|---|---|
| Intelligence | 26.3 | 27.4 | GPT-5.1 |
| Output speed | 130 t/s | 116 t/s | GPT-4.1 |
| Output price | $8.00/1M | $10.00/1M | GPT-4.1 |
| Context | 1048K | 400K | GPT-4.1 |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: GPT-5.1GPT-5.1 scores 27.4 on the intelligence_index compared to GPT-4.1's 26.3. This edge supports its listed strength in strong multimodal integration. GPT-4.1 relies on its GPT lineage for reasoning but trails in the index.
Speed
Winner: GPT-4.1GPT-4.1 delivers 129.94 tokens per second versus GPT-5.1's 115.83 t/s. The higher speed aligns with its suitability for large-scale processing. GPT-5.1 notes potential latency at maximum context as a limitation.
Pricing
Winner: GPT-4.1GPT-4.1 costs $8 per million tokens while GPT-5.1 costs $10 per million. The lower price supports GPT-4.1 for extended or high-volume use. Both share the same proprietary OpenAI provider model.
Context Window
Winner: GPT-4.1GPT-4.1 provides 1,047,576 tokens of context against GPT-5.1's 400,000. This larger window matches its strength in handling very large inputs across modalities. GPT-5.1's limitation mentions potential latency with its maximum context.
GPT-4.1
Pros
- +Handles very large context windows
- +Processes images, text, and files together
- +Strong reasoning from OpenAI GPT lineage
- +Flexible multimodal inputs
Cons
- –Closed-source with no public weights
- –May hallucinate on complex tasks
- –High compute cost for full context
GPT-5.1
Pros
- +Very large context window
- +Native support for images, text, and files
- +Strong multimodal integration
Cons
- –No audio or video modalities
- –Performance details unverified beyond specs
- –Potential latency with maximum context
Summary: GPT-4.1 vs GPT-5.1
Select GPT-5.1 when intelligence and multimodal integration are priorities. Select GPT-4.1 when speed, cost, and maximum context size drive the decision. Both handle images, text, and files but differ clearly on the measured metrics.
Frequently asked questions
GPT-5.1 is better on intelligence while GPT-4.1 leads on speed, price, and context size; neither is universally superior.