GPT-5.6 Sol Pro
by OpenAI · openai/gpt-5.6-sol-pro · #305 cheapest of 325 paid models
Prices updated Jul 22, 2026, 1:35 AM UTC · refreshed hourly
GPT-5.6 Sol Pro is the same underlying model as [GPT-5.6 Sol](https://openrouter.ai/openai/gpt-5.6-sol), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
Compare vs:Claude Sonnet 5Claude Opus 4.6Claude Haiku 4.5Gemini 3.6 Flash
Pricing
Input
$5.00
per 1M tokens
Output
$30.00
per 1M tokens
Blended (3:1)
$11.25
3 input : 1 output
Cache read
$0.50
per 1M cached tokens
Cache write
$6.25
per 1M tokens
Cache & batch economics
Effective prices for GPT-5.6 Sol Pro with prompt caching.
| Cache hit rate | Effective blended $/1M | Example request* | vs no cache |
|---|---|---|---|
| 0% | $11.25 | $0.54 | — |
| 50% | $9.56 | $0.315 | −42% |
| 90% | $8.21 | $0.135 | −75% |
*Example: 100K sticky context + 2K new input + 1K output. Batch discount is an approximate 50% off list rates for this provider’s batch API. Confirm on the vendor’s pricing page.
What a request costs
| Workload | Input tokens | Output tokens | Cost / request | Cost / 1K requests |
|---|---|---|---|---|
| Short chat message | 500 | 300 | $0.0115 | $11.50 |
| Document summary | 8,000 | 1,000 | $0.07 | $70.00 |
| Codebase question (RAG) | 30,000 | 2,000 | $0.21 | $210.00 |
| Long-context analysis | 150,000 | 5,000 | $0.9 | $900.00 |
Specs
Context window
1.05M
tokens
Max output
128K
tokens
Input modalities
file, image, text
Tokenizer
GPT