GPT-5.2 Codex

GPT-5.2 Codex is the software engineering version of OpenAI's GPT-5.2, an upgrade over GPT-5.1 Codex for coding workflows.

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compare models

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input · usd / 1m tok

$1.75

output · usd / 1m tok

$14.00

context window

400ktokens

modalities · in → out

pricing

base api ratesusd per 1m tokens

input: $1.75
output: $14.00
cache read: $0.175

providers

Azure OpenAI hosts GPT-5.2 Codex. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

Azure OpenAI

specifications

takes text and image in, gives text outopenai/gpt-5.2-codex

creatorOpenAI
model typeText generation
context window400,000 tokens
maximum outputnot published
input
takes text and image in, gives text out
outputtext
tool callingnot verified
releaseddec 18, 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-5.2-codex",
    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-5.2-codex",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

intelligence index

28.5#37 of 90 models on the gateway

omniscience-2.2#41 of 86
gpqa89.9%#37 of 88
humanity’s last exam35.7%#37 of 89

Tau292.1%
GPQA89.9%
AA-LCR82.3%
IFBench77.6%
MMMU-Pro76.3%
Terminal-Bench Hard37.1%
Humanity’s Last Exam35.7%
CritPt8.7%

Intelligence Index28.50
Omniscience Index-2.17
intelligence index (API)28.5

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 2026-09-10.

compare GPT-5.2 Codex 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-5.2 Codex?

GPT-5.2 Codex is the software engineering version of OpenAI's GPT-5.2, an upgrade over GPT-5.1 Codex for coding workflows. It is built for both interactive development sessions and long, independent execution of complex engineering tasks in Codex-style agentic environments.

How much does GPT-5.2 Codex cost?

GPT-5.2 Codex costs $1.75 per million input tokens and $14.00 per million output tokens through the Impossibl API. Cache reads cost $0.175 per million tokens. All rates are in USD.

view the pricing table ↑

What is the context length of GPT-5.2 Codex?

GPT-5.2 Codex has a 400,000-token context window through the Impossibl API.

What inputs and outputs does GPT-5.2 Codex support?

GPT-5.2 Codex accepts text and image as input. GPT-5.2 Codex returns text.

How do I use GPT-5.2 Codex through an API?

GPT-5.2 Codex is available through the Impossibl API. Use openai/gpt-5.2-codex 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-5.2 Codex released?

OpenAI released GPT-5.2 Codex on December 18, 2025.

Creator release announcement ↗

this page describes GPT-5.2 Codex 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 →