Model Comparison
GPT-4 vs GPT-5.6 SolWhich is better in 2026?
GPT-5.6 Sol significantly outperforms across most benchmarks. GPT-5.6 Sol is 3.3x cheaper per token.
Verdict: GPT-4 vs GPT-5.6 Sol — which is better?
GPT-4 (by OpenAI) and GPT-5.6 Sol (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-4 outperforms in 0 benchmarks, while GPT-5.6 Sol is better at 1 benchmark (GPQA). GPT-5.6 Sol significantly outperforms across most benchmarks.
On price, GPT-5.6 Sol is roughly 3.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.6 Sol also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-4 if…
- you want predictable pricing at $30.00/M input and $60.00/M output
Choose GPT-5.6 Sol if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- cost matters — it's about 3.3x cheaper per token
- you process long inputs — it offers a 1,050,000 token context window
- you want the most recent training data — it shipped Jul 2026
Performance Benchmarks
Comparative analysis across standard metrics
GPT-4 outperforms in 0 benchmarks, while GPT-5.6 Sol is better at 1 benchmark (GPQA).
GPT-5.6 Sol significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-4 ($30.00/1M tokens) is 6.0x more expensive than GPT-5.6 Sol ($5.00/1M tokens).
For output processing, GPT-4 ($60.00/1M tokens) is 2.0x more expensive than GPT-5.6 Sol ($30.00/1M tokens).
In conclusion, GPT-4 is more expensive than GPT-5.6 Sol.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Sol accepts 1,050,000 input tokens compared to GPT-4's 32,768 tokens. GPT-5.6 Sol can generate longer responses up to 128,000 tokens, while GPT-4 is limited to 32,768 tokens.
Input Capabilities
Supported data types and modalities
Both GPT-4 and GPT-5.6 Sol support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-4
GPT-5.6 Sol
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 was released on 2023-06-13, while GPT-5.6 Sol was released on 2026-07-09.
GPT-5.6 Sol is 37 months newer than GPT-4.
Jun 13, 2023
3.1 years ago
Jul 9, 2026
1 weeks ago
3.1yr newerKnowledge Cutoff
When training data ends
GPT-4 has a knowledge cutoff of 2022-12-31, while GPT-5.6 Sol has a cutoff of 2026-02-16.
GPT-5.6 Sol has more recent training data (up to 2026-02-16), making it potentially better informed about events through that date compared to GPT-4 (2022-12-31).
Dec 2022
Feb 2026
3.2 yr newerProvider Availability
GPT-4 is available from Azure, OpenAI. GPT-5.6 Sol is available from OpenAI.
GPT-4
GPT-5.6 Sol
Outputs Comparison
Key Takeaways
GPT-4
View detailsOpenAI
No standout differentiators in the data we have for this pair.
GPT-5.6 Sol
View detailsOpenAI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-4 and GPT-5.6 Sol side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-4 vs GPT-5.6 Sol.