GPT-5.6 Sol vs Solar Pro 4
GPT-5.6 Sol leads the LLM Stats Score 57.2 to 36.0. Solar Pro 4 is 21.4x cheaper per token.
OpenAI · Upstage · Updated for 2026
Which is better?
GPT-5.6 Sol leads the overall LLM Stats Score 57.2 to 36.0, ranking #1 overall.
In the 3 individual benchmarks reported for both models, GPT-5.6 Sol wins 3; this is a narrower head-to-head signal than the composite indexes.
On price, Solar Pro 4 is roughly 21.4x 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.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5.6 Sol
- overall performance matters — it scores 57.2 and ranks #1 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
- you process long inputs — it offers a 1,050,000 token context window
Choose Solar Pro 4
- cost matters — it's about 21.4x cheaper per token
- you want the most recent training data — it shipped Aug 2026
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
44 reported for GPT-5.6 Sol · 9 for Solar Pro 4
GPT-5.6 Sol outperforms in 3 benchmarks (BrowseComp, GPQA, Terminal-Bench 2.1), while Solar Pro 4 is better at 0 benchmarks.
GPT-5.6 Sol significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.6 Sol ($5.00/1M tokens) is 16.7x more expensive than Solar Pro 4 ($0.30/1M tokens).
For output processing, GPT-5.6 Sol ($30.00/1M tokens) is 25.0x more expensive than Solar Pro 4 ($1.20/1M tokens).
In conclusion, GPT-5.6 Sol is more expensive than Solar Pro 4.*
* 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 Solar Pro 4's 524,288 tokens. Solar Pro 4 can generate longer responses up to 131,072 tokens, while GPT-5.6 Sol is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
GPT-5.6 Sol supports multimodal inputs, whereas Solar Pro 4 does not.
GPT-5.6 Sol can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5.6 Sol
Solar Pro 4
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-5.6 Sol was released on 2026-07-09, while Solar Pro 4 was released on 2026-08-06.
Solar Pro 4 is 1 month newer than GPT-5.6 Sol.
Jul 9, 2026
1 months ago
Aug 6, 2026
3 weeks ago
4w newerKnowledge Cutoff
When training data ends
GPT-5.6 Sol has a documented knowledge cutoff of 2026-02-16, while Solar Pro 4's cutoff date is not specified.
We can confirm GPT-5.6 Sol's training data extends to 2026-02-16, but cannot make a direct comparison without Solar Pro 4's cutoff date.
Feb 2026
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Provider Availability
GPT-5.6 Sol is available from OpenAI. Solar Pro 4 is available from Upstage.
GPT-5.6 Sol
Solar Pro 4
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.6 Sol and Solar Pro 4 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.6 Sol vs Solar Pro 4.