OpenAI o3

OpenAI o3 is a reasoning model in OpenAI's o-series, well-rounded across math, science, coding, and visual reasoning, and strong at technical writing and instruction following.

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input · usd / 1m tok

$2.00

output · usd / 1m tok

$8.00

context window

200ktokens

modalities · in → out

pricing

base api ratesusd per 1m tokens

input: $2.00
output: $8.00
cache read: $0.50

providers

Different companies host OpenAI o3. 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/o3

creatorOpenAI
model typeText generation
context window200,000 tokens
maximum outputnot published
input
takes text and image in, gives text out
outputtext
tool callingnot verified
releasedapr 16, 2025
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/o3",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

# 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/o3",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

intelligence index

20.2#76 of 108 models on the gateway

omniscience-15.6#57 of 84
gpqa82.7%#50 of 80
humanity’s last exam20.1%#59 of 87

AIME 202588.3%
GPQA82.7%
LiveCodeBench80.8%
Tau280.7%
AA-LCR74.7%
IFBench71.4%
MMMU-Pro70.1%
Terminal-Bench Hard37.1%
Humanity’s Last Exam20.1%
CritPt1.1%

Intelligence Index20.20
Omniscience Index-15.55
intelligence index (API)20.2

view source ↗all source data and breakdowns (json) ↗

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 2026-10-14.

compare OpenAI o3 with other models

frontier labs and open weights, best-ranked firstusd / 1m tok · in / out

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impossibl models --all →

frequently asked questions

What is OpenAI o3?

OpenAI o3 is a reasoning model in OpenAI's o-series, well-rounded across math, science, coding, and visual reasoning, and strong at technical writing and instruction following. It can reason with images and call tools agentically, sitting above the compact o4-mini in the series.

How much does OpenAI o3 cost?

OpenAI o3 costs $2.00 per million input tokens and $8.00 per million output tokens through the Impossibl API. Cache reads cost $0.50 per million tokens. All rates are in USD.

view the pricing table ↑

What is the context length of OpenAI o3?

OpenAI o3 has a 200,000-token context window through the Impossibl API.

What inputs and outputs does OpenAI o3 support?

OpenAI o3 accepts text and image as input. OpenAI o3 returns text.

How do I use OpenAI o3 through an API?

OpenAI o3 is available through the Impossibl API. Use openai/o3 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 OpenAI o3 released?

OpenAI released OpenAI o3 on April 16, 2025.

Creator release announcement ↗

this page describes OpenAI o3 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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