Model Comparison
GPT-5.1 vs GPT-5.1 InstantWhich is better in 2026?
Both models are evenly matched across the benchmarks. GPT-5.1 and GPT-5.1 Instant cost the same.
Verdict: GPT-5.1 vs GPT-5.1 Instant — which is better?
GPT-5.1 (by OpenAI) and GPT-5.1 Instant (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
GPT-5.1 outperforms in 0 benchmarks, while GPT-5.1 Instant is better at 0 benchmarks. Both models are evenly matched across the benchmarks.
Choose GPT-5.1 if…
- you want the most recent training data — it shipped Nov 2025
Choose GPT-5.1 Instant if…
- you want the strongest raw capability — it leads on 9 of 9 shared benchmarks
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.1 outperforms in 0 benchmarks, while GPT-5.1 Instant is better at 0 benchmarks.
Both models are evenly matched across the benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.1 ($1.25/1M tokens) costs the same as GPT-5.1 Instant ($1.25/1M tokens).
For output processing, GPT-5.1 ($10.00/1M tokens) costs the same as GPT-5.1 Instant ($10.00/1M tokens).
In conclusion, GPT-5.1 and GPT-5.1 Instant cost the same.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Both models have the same input context window of 400,000 tokens. Both models can generate responses up to 128,000 tokens.
Input Capabilities
Supported data types and modalities
Both GPT-5.1 and GPT-5.1 Instant support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.1
GPT-5.1 Instant
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-5.1 was released on 2025-11-13, while GPT-5.1 Instant was released on 2025-11-12.
GPT-5.1 is 0 month newer than GPT-5.1 Instant.
Nov 13, 2025
8 months ago
1d newerNov 12, 2025
8 months ago
Knowledge Cutoff
When training data ends
GPT-5.1 has a documented knowledge cutoff of 2024-09-30, while GPT-5.1 Instant's cutoff date is not specified.
We can confirm GPT-5.1's training data extends to 2024-09-30, but cannot make a direct comparison without GPT-5.1 Instant's cutoff date.
Sep 2024
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Provider Availability
GPT-5.1 is available from OpenAI. GPT-5.1 Instant is available from OpenAI.
GPT-5.1
GPT-5.1 Instant
Outputs Comparison
Key Takeaways
GPT-5.1
View detailsOpenAI
No standout differentiators in the data we have for this pair.
No standout differentiators in the data we have for this pair.
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-5.1 and GPT-5.1 Instant side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-5.1 vs GPT-5.1 Instant.