The short answer
GPT-5.6 Sol is an OpenAI model priced at $5 per million input tokens and $30 per million output tokens, with a 1M token context window. One standard answer, meaning 1,000 tokens in and 500 tokens out, costs $0.0200. Inside Whizi it costs 20 credits per message and needs the Powerhouse plan or above.
That makes it one of the more expensive models in the catalogue: 2 of the 89 priced models cost more per answer, and 86 cost less.
What GPT-5.6 Sol costs
List rates are what the provider charges per token. The cost of one standard answer is the more useful number, because it prices the same unit of work across every model regardless of how each one is billed.
| Input, per million tokens | $5 |
| Output, per million tokens | $30 |
| One standard answer | $0.0200 |
| One thousand answers | $20.00 |
| Context window | 1M tokens |
| Credits per message in Whizi | 20 |
| Minimum Whizi plan | Powerhouse |
| Rank by cost, of 89 priced models | 87 |
Prices are the published OpenAI rates as carried by OpenRouter, last refreshed 2026-08-08. The full dataset covering all 100 models from 28 providers is the AI model cost index, which is free to reuse with attribution.
What it costs inside Whizi
Whizi meters messages in credits rather than tokens, and GPT-5.6 Sol is charged at 20 credits per message. The cost does not change with the length of your message or the length of the answer, so a one line question and a long document analysis cost the same.
| Plan | Price per month | Monthly credits | Messages on this model |
|---|---|---|---|
| Powerhouse | $49.99, or $34.99 billed yearly | 8,000 | 400 |
GPT-5.6 Sol is part of the Powerhouse catalogue. Anything not explicitly listed on the Starter or Pro tiers resolves to Powerhouse, which is the deliberate default for the frontier and specialist models. See plans and limits.
How it compares on price
Against the cheapest model in the index, Ling-2.6-flash at $0.000025 per answer, GPT-5.6 Sol costs 800 times more. Against the median, GLM 4.6 at $0.0015, it costs 13 times more.
Its nearest neighbours from OpenAI:
| Model | One answer | Context | Credits |
|---|---|---|---|
| GPT-5.4 Mini | $0.0030 | 400K | 4 |
| GPT-5.6 Terra | $0.0040 | 1M | 4 |
| GPT-5.4 | $0.0100 | 1M | 15 |
| GPT-5.6 Sol (this page) | $0.0200 | 1M | 20 |
If GPT-5.6 Sol is more model than a given task needs, GPT-5.4 is the cheaper OpenAI option at $0.0100 per answer and 15 credits per message. Routing routine work down a tier is the single biggest thing you can do to make an allowance last.
The context window in practice
GPT-5.6 Sol accepts 1M tokens of context, which is roughly 1600 pages of text. That is well above the median for the priced catalogue.
Advertised context and usable context are not the same thing. Recall tends to degrade before the stated limit is reached, particularly for material in the middle of a long input, so the practical test is to upload a long document and ask about something buried halfway through rather than trusting the number.
The number matters most when you are working from your own files. If a document is too long for the model you picked, switching to a larger-context model in the same conversation carries the thread across, so you are not starting over. See switching models mid-conversation.
- Input $5 and output $30 per million tokens
- $0.0200 for one standard answer, $20.00 for a thousand
- 1M token context window
- 20 credits per message inside Whizi
- Requires the Powerhouse plan or above
- Ranks 87 of 89 priced models by cost per answer
Frequently asked questions
How much does GPT-5.6 Sol cost?
$5 per million input tokens and $30 per million output tokens at list rates, which works out to $0.0200 for one standard answer of 1,000 tokens in and 500 out, or $20.00 for a thousand of them. Inside Whizi it is 20 credits per message on a monthly allowance, rather than metered per token.
Which Whizi plan includes GPT-5.6 Sol?
Powerhouse and above, which is $49.99 per month or $34.99 billed yearly. At 20 credits per message, a Powerhouse allowance of 8,000 credits covers 400 messages on this model if you spend the whole allowance here, and most people mix in a 1 credit model for routine work so it goes further.
What is the context window of GPT-5.6 Sol?
1M tokens, which is roughly 1600 pages of text and sits well above the median for the priced catalogue. Treat that as the ceiling rather than the working figure: recall usually degrades before the stated limit, especially for content in the middle of a long input.
Is GPT-5.6 Sol expensive compared to other models?
It ranks 87 of 89 priced models by cost per answer, so 2 cost more and 86 cost less. The spread across the whole catalogue is about 4800 times from cheapest to priciest, which is far wider than most people assume, so "expensive" only means anything relative to the specific alternative you would otherwise use.