GPT-5.6 Sol — Specifications
| Developer | OpenAI |
|---|---|
| Type | Reasoning / agentic |
| Modality | Text, vision |
| Parameters | Undisclosed |
| Context window | 1.05M |
| Max output | 128K |
| License | Proprietary |
| Open weights | No |
| Released | 2026-06 |
| Input price | $5.00 /1M |
| Output price | $30.00 /1M |
| API providers | OpenAI API, Microsoft Azure AI |
Benchmarks
| Artificial Analysis Intelligence Index | 59. |
|---|
What is GPT-5.6 Sol?
GPT-5.6 Sol is the flagship of OpenAI’s GPT-5.6 series, scoring 59 on the Artificial
Analysis Intelligence Index. Headline pricing matches GPT-5.5 at $5 in / $30 out per million
tokens with a ~1.05M-token context, available through the OpenAI API and Microsoft Azure
AI.
The long-context billing is the thing to read carefully. Requests above 272K input tokens
are charged at 2× the input rate and 1.5× the output rate — effectively $10 / $45 — so
long-context work costs materially more than the advertised price suggests. A single feature
that routinely pastes in large documents can therefore run at nearly double the modelled
cost, and because the threshold is crossed per request rather than per account, the overage
is invisible until it appears on the invoice. Instrument prompt sizes before you scale, and
consider whether a model with flat pricing across its whole window is cheaper in practice for
your specific mix. At 59 on the intelligence index Sol is genuinely near the top of the
field; the question is whether your workload sits above or below that 272K line.
GPT-5.6 Sol pricing: API cost per 1M tokens
| Input (per 1M tokens) | $5.00 |
|---|---|
| Output (per 1M tokens) | $30.00 |
| Output/input ratio | 6× |
| Blended (4:1 in:out) | $10.00 per 1M tokens |
What GPT-5.6 Sol costs per month
Real monthly spend at a 4:1 input-to-output mix — the ratio a typical chat or RAG workload actually produces.
| Workload | Tokens / month | Cost / month |
|---|---|---|
| Side project | 1M in / 0.25M out | $13 |
| Small team | 20M in / 5M out | $250 |
| Production | 200M in / 50M out | $2,500 |
Run your own numbers in the AI API cost calculator.
Cheaper alternatives to GPT-5.6 Sol
| Model | Blended $/1M | You save |
|---|---|---|
| Mistral 7B open | $0.0220 | 100% cheaper |
| Llama 3.1 8B open | $0.0220 | 100% cheaper |
| Mistral NeMo 12B open | $0.0240 | 100% cheaper |
Frequently asked questions
How much does GPT-5.6 Sol cost per 1M tokens?
GPT-5.6 Sol costs $5.00 per 1M input tokens and $30.00 per 1M output tokens. At a typical 4:1 input-to-output mix that blends to about $10.00 per 1M tokens.
How much does GPT-5.6 Sol cost per month?
A small-team workload of 20M input and 5M output tokens a month costs about $250 on GPT-5.6 Sol. A side project (1M in / 0.25M out) costs roughly $12.50.
What is a cheaper alternative to GPT-5.6 Sol?
Mistral 7B is the strongest cheaper option in our database at $0.0220 per 1M blended — about 100% less than GPT-5.6 Sol. It is also open-weight, so self-hosting is an option.
Can I run GPT-5.6 Sol locally?
No. GPT-5.6 Sol is a closed, API-only model — the weights are not released, so it cannot be self-hosted.
Why does GPT-5.6 Sol charge more for output than input?
Output tokens are generated one at a time and cannot be batched the way a prompt can, so they cost the provider more to serve. GPT-5.6 Sol charges 6× more for output, which is why prompt-heavy workloads are far cheaper to run than generation-heavy ones.
Prices are the published list rates for the model's primary API and are reviewed as providers change them. Volume, batch and cached-input discounts are not included. Compare every model side by side in the AI models database or the LLM leaderboard.
