GPT-5.6 Sol
GPT-5.6 Sol is the flagship tier of OpenAI's GPT-5.6 series, positioned for complex professional work such as multi-step reasoning, coding, and agentic workflows.
input · usd / 1m tok
$4.00
output · usd / 1m tok
$20.00
context window
1.05mtokens
modalities · in → out
takes text and image in, gives text out
pricing
base api ratesusd per 1m tokens
- input
- $4.00over 272k · $8.00
- output
- $20.00over 272k · $30.00
- cache read
- $0.40over 272k · $0.80
- cache write · default ttl
- $5.00over 272k · $10.00
brackets are by input tokens per request: a request over a threshold is billed at that bracket's rates for all of its tokens. cache creation can have a separate charge.
providers
Different companies host GPT-5.6 Sol. Impossibl routes your request intelligently and handles failover automatically when a provider is down.
- Azure OpenAI
- OpenAI
specifications
takes text and image in, gives text outopenai/gpt-5.6-sol
- creatorOpenAI
- model typeText generation
- context window1,050,000 tokens
- maximum outputnot published
- input
takes text and image in, gives text out
- outputtext
- tool callingnot verified
- releasedjul 9, 2026
- endpoint
/v1/chat/completions
unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports. see the model documentation for integration details.
try it · your prompt, this model, live
# responses API
import os
from openai import OpenAI
client = OpenAI(
api_key=os.environ["IMPOSSIBL_API_KEY"],
base_url="https://api.impossibl.com/v1",
)
resp = client.responses.create(
model="openai/gpt-5.6-sol",
input="",
)
print(resp.output_text)
edit the prompt, then run
benchmarks
intelligence index
47.0#13 of 113 models on the gateway
- coding index77.4#3 of 66
- agentic index50.2#10 of 54
- omniscience22.0#15 of 90
- gpqa94.1%#3 of 82
- humanity’s last exam49.5%#6 of 93
- GPQA94.1%
- Tau285.1%
- AA-LCR84.0%
- MMMU-Pro83.4%
- IFBench72.7%
- Terminal-Bench Hard65.9%
- AutomationBench Partial60.1%
- SciCode57.1%
- ITBench56.2%
- Humanity’s Last Exam49.5%
- AnalystAgent47.5%
- Tau Banking44.3%
- CritPt32.3%
- Multilingual LCR30.0%
- GDP.pdf All-pass27.2%
- Intelligence Index46.97
- Omniscience Index21.97
- GDPval Elo1608.63
- legal index (API)49.8
- coding index (API)77.4
- agentic index (API)50.2
- economics index (API)52.9
- engineering index (API)48.9
- intelligence index (API)47
- strategy and ops index (API)54.3
- finance and accounting index (API)49
- healthcare and medical index (API)45.4
each configuration is listed separately; these evaluations describe the tested model configuration, and performance and costs can differ on impossibl. unmeasured scores are omitted and api values keep their source units. last checked 2026-10-21.
compare GPT-5.6 Sol with other models
frontier labs and open weights, best-ranked firstusd / 1m tok · in / out
- anthropic/claude-opus-5-5$4.00 / $20.00compare →
- moonshotai/kimi-k3.1-pro$2.00 / $10.00compare →
- google/gemini-4-argon$2.00 / $10.00compare →
- meta/muse-wonder$4.00 / $20.00compare →
frequently asked questions
What is GPT-5.6 Sol?
GPT-5.6 Sol is the flagship tier of OpenAI's GPT-5.6 series, positioned for complex professional work such as multi-step reasoning, coding, and agentic workflows. It corresponds to the unsuffixed tier of earlier GPT-5 generations, with text and image input, configurable reasoning effort, and computer-use and code-interpreter tools.
How much does GPT-5.6 Sol cost?
GPT-5.6 Sol costs $4.00 per million input tokens and $20.00 per million output tokens through the Impossibl API. Cache reads cost $0.40 per million tokens; cache writes cost $5.00 per million tokens. These base rates apply through 272,000 total input tokens per request. Above 272,000 input tokens, the long-context rates in the pricing table apply to the whole request. All rates are in USD.
What is the context length of GPT-5.6 Sol?
GPT-5.6 Sol has a 1,050,000-token context window through the Impossibl API.
What inputs and outputs does GPT-5.6 Sol support?
GPT-5.6 Sol accepts text and image as input. GPT-5.6 Sol returns text.
How do I use GPT-5.6 Sol through an API?
GPT-5.6 Sol is available through the Impossibl API. Use openai/gpt-5.6-sol as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.
When was GPT-5.6 Sol released?
OpenAI released GPT-5.6 Sol on July 9, 2026.
this page describes GPT-5.6 Sol as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes. model descriptions and release dates, where available, use the creator sources linked under the answers above.
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