Text generation / OpenAI

GPT-5.6 Sol

GPT-5.6 Sol is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $4.00 per million input tokens. The advertised output rate is $20.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

api id: openai/gpt-5.6-sol

model as markdown ↗

how much does gpt-5.6 sol cost?

published base api rates · usd per 1m tokens

input
$4.00
output
$20.00
cache read
$0.40
cache write · default ttl
$5.00
long-context rates · usd per 1m tokens
total inputinputoutputcache readcache write
over 272,000 tokens$8.00$30.00$0.80$10.00

crossing a threshold applies that bracket to the whole request. cache creation can have a separate charge.

rates are published by the impossibl api. balance-purchase fees, taxes, tool charges, and workspace-specific pricing are separate.

specifications & capabilities

creator
OpenAI
model type
Text generation
context window
1.05m tokens
maximum output
not published in the catalog
input types
text, image
output types
text
tool calling
not verified in the catalog

unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports.

published endpoint

/v1/chat/completions

see the model documentation for integration details.

estimate your usage

estimate your api cost

estimate text token usage for your workload. all amounts are in usd.

token workload

total input, including cached tokens

include billable reasoning tokens

the same token usage in each request

a subset of total input, never additional tokens

GPT-5.6 Sol

$14.00

estimated usage cost

1,000 requests × (1,000 uncached input × $4.00 + 500 output × $20.00) / 1,000,000 = $14.00

base rates: up to 272,000 input tokens per request, inclusive.

estimates use published impossibl api usage rates. configured billing adjustments, funding fees, taxes, and custom workspace rates are excluded and may change the final amount.

image and audio usage, cache creation, and additional tool charges are excluded. reasoning tokens count as billable output, even when they are not visible in the response.

compare more Text generation models

independent benchmarks

Results from Artificial Analysis. Each configuration is listed separately. These evaluations describe the tested model configuration; performance and costs can differ on Impossibl. Last checked 2026-09-10.

GPT-5.6 Sol (max)
BenchmarkScore
Intelligence Index47.06
Omniscience Index21.97
GPQA94.14%
Humanity’s Last Exam49.49%
SciCode57.06%
CritPt32.29%
Terminal-Bench v2.188.01%
Terminal-Bench v4.039.90%
Terminal-Bench Hard65.91%
AA-LCR84.00%
Multilingual LCR26.11%
Harvey LAB87.18%
GDPval Elo1624.11
GDP.pdf All-pass27.20%
AutomationBench Partial60.08%
AnalystAgent47.50%
MMMU-Pro83.41%
IFBench72.65%
Tau285.09%
Tau Banking44.33%
ITBench56.21%
coding index (API)77.4
agentic index (API)50.5
intelligence index (API)47.1

Unmeasured scores are omitted. API values retain their source units.

view source ↗

all source data and breakdowns (JSON) ↗

GPT-5.6 Sol (high)
BenchmarkScore
Intelligence Index42.50
Omniscience Index20.37
GPQA92.83%
Humanity’s Last Exam46.01%
SciCode57.75%
CritPt25.71%
Terminal-Bench v2.187.27%
Terminal-Bench v4.020.71%
Terminal-Bench Hard62.12%
AA-LCR81.67%
Multilingual LCR17.22%
GDPval Elo1524.01
GDP.pdf All-pass27.80%
AutomationBench Partial55.31%
MMMU-Pro81.85%
IFBench69.18%
Tau283.33%
Tau Banking36.70%
coding index (API)77.2
agentic index (API)44.7
intelligence index (API)42.5

Unmeasured scores are omitted. API values retain their source units.

view source ↗

all source data and breakdowns (JSON) ↗

GPT-5.6 Sol (low)
BenchmarkScore
Intelligence Index33.80
Omniscience Index18.87
GPQA89.80%
Humanity’s Last Exam39.39%
SciCode56.37%
CritPt14.86%
Terminal-Bench v2.176.78%
Terminal-Bench v4.01.01%
Terminal-Bench Hard60.61%
AA-LCR78.00%
Multilingual LCR12.78%
GDPval Elo1354.85
GDP.pdf All-pass21.00%
AutomationBench Partial40.99%
MMMU-Pro80.98%
IFBench66.53%
Tau276.02%
Tau Banking29.07%
coding index (API)69.7
agentic index (API)32.6
intelligence index (API)33.8

Unmeasured scores are omitted. API values retain their source units.

view source ↗

all source data and breakdowns (JSON) ↗

GPT-5.6 Sol (medium)
BenchmarkScore
Intelligence Index39.48
Omniscience Index19.40
GPQA92.63%
Humanity’s Last Exam42.22%
SciCode57.41%
CritPt22.86%
Terminal-Bench v2.186.14%
Terminal-Bench v4.014.65%
Terminal-Bench Hard62.88%
AA-LCR80.33%
Multilingual LCR15.00%
GDPval Elo1456.10
GDP.pdf All-pass26.20%
AutomationBench Partial51.33%
MMMU-Pro81.39%
IFBench69.59%
Tau280.99%
Tau Banking36.49%
coding index (API)76.3
agentic index (API)40.5
intelligence index (API)39.5

Unmeasured scores are omitted. API values retain their source units.

view source ↗

all source data and breakdowns (JSON) ↗

GPT-5.6 Sol (Non-reasoning)
BenchmarkScore
Intelligence Index28.33
Omniscience Index1.10
GPQA78.99%
Humanity’s Last Exam16.68%
CritPt5.14%
Terminal-Bench v2.174.16%
AA-LCR62.33%
GDPval Elo1299.14
MMMU-Pro71.91%
Tau Banking19.59%
coding index (API)65.1
agentic index (API)29.4
intelligence index (API)28.3

Unmeasured scores are omitted. API values retain their source units.

view source ↗

all source data and breakdowns (JSON) ↗

GPT-5.6 Sol (xhigh)
BenchmarkScore
Intelligence Index44.14
Omniscience Index20.98
GPQA93.13%
Humanity’s Last Exam47.31%
SciCode57.06%
CritPt28.57%
Terminal-Bench v2.189.51%
Terminal-Bench v4.024.75%
Terminal-Bench Hard61.36%
AA-LCR82.33%
Multilingual LCR18.33%
GDPval Elo1584.88
GDP.pdf All-pass27.60%
AutomationBench Partial55.31%
MMMU-Pro82.66%
IFBench71.02%
Tau284.80%
Tau Banking38.14%
coding index (API)78.3
agentic index (API)47.8
intelligence index (API)44.1

Unmeasured scores are omitted. API values retain their source units.

view source ↗

all source data and breakdowns (JSON) ↗

frequently asked questions

What is GPT-5.6 Sol?

GPT-5.6 Sol is a text-generation model from OpenAI, available through the Impossibl API.

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.

view the pricing table ↑

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.

follow the api quickstart →

When was GPT-5.6 Sol released?

OpenAI released GPT-5.6 Sol on July 9, 2026.

sources & coverage

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.

view the source catalog ↗

model descriptions and release dates, where available, use the creator sources linked in the faq. api prices and limits use the impossibl catalog. benchmark results, where available, are credited to Artificial Analysis in the benchmarks section. report a correction →