GPT-5 nano

GPT-5 nano is the smallest and fastest tier of OpenAI's GPT-5 family, optimised for developer tools, rapid interactions, and ultra-low-latency environments.

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input · usd / 1m tok

$0.05

output · usd / 1m tok

$0.40

context window

400ktokens

modalities · in → out

pricing

base api ratesusd per 1m tokens

input: $0.05
output: $0.40
cache read: $0.005

providers

Different companies host GPT-5 nano. 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-nano

creatorOpenAI
model typeText generation
context window400,000 tokens
maximum outputnot published
input
takes text and image in, gives text out
outputtext
tool callingnot verified
releasedaug 7, 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/gpt-5-nano",
    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/gpt-5-nano",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

intelligence index

13.0#90 of 108 models on the gateway

omniscience-28.7#68 of 84
gpqa67.6%#69 of 80
humanity’s last exam9.5%#70 of 87

AIME 202583.7%
LiveCodeBench78.9%
GPQA67.6%
IFBench67.6%
MMMU-Pro61.0%
AA-LCR45.0%
Tau236.5%
Terminal-Bench Hard12.1%
Humanity’s Last Exam9.5%
CritPt0.0%

Intelligence Index12.99
Omniscience Index-28.67
intelligence index (API)13

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 GPT-5 nano 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 GPT-5 nano?

GPT-5 nano is the smallest and fastest tier of OpenAI's GPT-5 family, optimised for developer tools, rapid interactions, and ultra-low-latency environments. It offers less reasoning depth than GPT-5 and GPT-5 mini, trading capability for speed and throughput on high-volume tasks.

How much does GPT-5 nano cost?

GPT-5 nano costs $0.05 per million input tokens and $0.40 per million output tokens through the Impossibl API. Cache reads cost $0.005 per million tokens. All rates are in USD.

view the pricing table ↑

What is the context length of GPT-5 nano?

GPT-5 nano has a 400,000-token context window through the Impossibl API.

What inputs and outputs does GPT-5 nano support?

GPT-5 nano accepts text and image as input. GPT-5 nano returns text.

How do I use GPT-5 nano through an API?

GPT-5 nano is available through the Impossibl API. Use openai/gpt-5-nano 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 nano released?

OpenAI released GPT-5 nano on August 7, 2025.

Creator release announcement ↗

this page describes GPT-5 nano 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.

view the source catalog ↗model as markdown ↗report a correction →