Model Comparison
GPT-5 nano vs GPT-5.1 InstantWhich is better in 2026?
GPT-5.1 Instant significantly outperforms across most benchmarks. GPT-5 nano is 25.0x cheaper per token.
Verdict: GPT-5 nano vs GPT-5.1 Instant — which is better?
GPT-5 nano (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 nano outperforms in 0 benchmarks, while GPT-5.1 Instant is better at 3 benchmarks (AIME 2025, FrontierMath, GPQA). GPT-5.1 Instant significantly outperforms across most benchmarks.
On price, GPT-5 nano is roughly 25.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Choose GPT-5 nano if…
- cost matters — it's about 25.0x cheaper per token
Choose GPT-5.1 Instant if…
- you want the strongest raw capability — it leads on 3 of 3 shared benchmarks
- you want the most recent training data — it shipped Nov 2025
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5 nano outperforms in 0 benchmarks, while GPT-5.1 Instant is better at 3 benchmarks (AIME 2025, FrontierMath, GPQA).
GPT-5.1 Instant significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5 nano ($0.05/1M tokens) is 25.0x cheaper than GPT-5.1 Instant ($1.25/1M tokens).
For output processing, GPT-5 nano ($0.40/1M tokens) is 25.0x cheaper than GPT-5.1 Instant ($10.00/1M tokens).
In conclusion, GPT-5.1 Instant is more expensive than GPT-5 nano.*
* 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 nano and GPT-5.1 Instant support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5 nano
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 nano was released on 2025-08-07, while GPT-5.1 Instant was released on 2025-11-12.
GPT-5.1 Instant is 3 months newer than GPT-5 nano.
Aug 7, 2025
10 months ago
Nov 12, 2025
7 months ago
3mo newerKnowledge Cutoff
When training data ends
GPT-5 nano has a documented knowledge cutoff of 2024-05-30, while GPT-5.1 Instant's cutoff date is not specified.
We can confirm GPT-5 nano's training data extends to 2024-05-30, but cannot make a direct comparison without GPT-5.1 Instant's cutoff date.
May 2024
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Provider Availability
GPT-5 nano is available from OpenAI. GPT-5.1 Instant is available from OpenAI.
GPT-5 nano
GPT-5.1 Instant
Outputs Comparison
Key Takeaways
GPT-5 nano
View detailsOpenAI
Detailed Comparison
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FAQ
Common questions about GPT-5 nano vs GPT-5.1 Instant.