Model Comparison
GPT-5.1 Instant vs o1-previewWhich is better in 2026?
GPT-5.1 Instant significantly outperforms across most benchmarks. GPT-5.1 Instant is 7.6x cheaper per token.
Verdict: GPT-5.1 Instant vs o1-preview — which is better?
GPT-5.1 Instant (by OpenAI) and o1-preview (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 Instant outperforms in 2 benchmarks (GPQA, SWE-Bench Verified), while o1-preview is better at 0 benchmarks. GPT-5.1 Instant significantly outperforms across most benchmarks.
On price, GPT-5.1 Instant is roughly 7.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.1 Instant also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-5.1 Instant if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- cost matters — it's about 7.6x cheaper per token
- you process long inputs — it offers a 400,000 token context window
- you want the most recent training data — it shipped Nov 2025
Choose o1-preview if…
- you want predictable pricing at $15.00/M input and $60.00/M output
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.1 Instant outperforms in 2 benchmarks (GPQA, SWE-Bench Verified), while o1-preview is better at 0 benchmarks.
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-5.1 Instant ($1.25/1M tokens) is 12.0x cheaper than o1-preview ($15.00/1M tokens).
For output processing, GPT-5.1 Instant ($10.00/1M tokens) is 6.0x cheaper than o1-preview ($60.00/1M tokens).
In conclusion, o1-preview is more expensive than GPT-5.1 Instant.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.1 Instant accepts 400,000 input tokens compared to o1-preview's 128,000 tokens. GPT-5.1 Instant can generate longer responses up to 128,000 tokens, while o1-preview is limited to 32,768 tokens.
Input Capabilities
Supported data types and modalities
GPT-5.1 Instant supports multimodal inputs, whereas o1-preview does not.
GPT-5.1 Instant can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5.1 Instant
o1-preview
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 Instant was released on 2025-11-12, while o1-preview was released on 2024-09-12.
GPT-5.1 Instant is 14 months newer than o1-preview.
Nov 12, 2025
7 months ago
1.2yr newerSep 12, 2024
1.8 years ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
GPT-5.1 Instant is available from OpenAI. o1-preview is available from OpenAI, Azure.
GPT-5.1 Instant
o1-preview
Outputs Comparison
Key Takeaways
o1-preview
View detailsOpenAI
No standout differentiators in the data we have for this pair.
Detailed Comparison
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FAQ
Common questions about GPT-5.1 Instant vs o1-preview.