GPT-4 Turbo vs GPT-5.1 Instant
GPT-5.1 Instant significantly outperforms across most benchmarks. GPT-5.1 Instant is 4.4x cheaper per token.
OpenAI · OpenAI · Updated for 2026
Which is better?
GPT-4 Turbo outperforms in 0 benchmarks, while GPT-5.1 Instant is better at 1 benchmark (GPQA). GPT-5.1 Instant significantly outperforms across most benchmarks.
On price, GPT-5.1 Instant is roughly 4.4x 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.
Based on current benchmark, pricing, and model metadata for 2026.
Choose GPT-4 Turbo
- you want predictable pricing at $10.00/M input and $30.00/M output
Choose GPT-5.1 Instant
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- cost matters — it's about 4.4x 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
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
GPT-4 Turbo outperforms in 0 benchmarks, while GPT-5.1 Instant is better at 1 benchmark (GPQA).
GPT-5.1 Instant significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-4 Turbo ($10.00/1M tokens) is 8.0x more expensive than GPT-5.1 Instant ($1.25/1M tokens).
For output processing, GPT-4 Turbo ($30.00/1M tokens) is 3.0x more expensive than GPT-5.1 Instant ($10.00/1M tokens).
In conclusion, GPT-4 Turbo 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 GPT-4 Turbo's 128,000 tokens. GPT-5.1 Instant can generate longer responses up to 128,000 tokens, while GPT-4 Turbo is limited to 4,096 tokens.
Input Capabilities
Supported data types and modalities
GPT-5.1 Instant supports multimodal inputs, whereas GPT-4 Turbo does not.
GPT-5.1 Instant can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-4 Turbo
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-4 Turbo was released on 2024-04-09, while GPT-5.1 Instant was released on 2025-11-12.
GPT-5.1 Instant is 19 months newer than GPT-4 Turbo.
Apr 9, 2024
2.4 years ago
Nov 12, 2025
9 months ago
1.6yr newerKnowledge Cutoff
When training data ends
GPT-4 Turbo has a documented knowledge cutoff of 2023-12-31, while GPT-5.1 Instant's cutoff date is not specified.
We can confirm GPT-4 Turbo's training data extends to 2023-12-31, but cannot make a direct comparison without GPT-5.1 Instant's cutoff date.
Dec 2023
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Provider Availability
GPT-4 Turbo is available from Azure, OpenAI. GPT-5.1 Instant is available from OpenAI.
GPT-4 Turbo
GPT-5.1 Instant
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-4 Turbo and GPT-5.1 Instant side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-4 Turbo vs GPT-5.1 Instant.