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OpenAI · Released Sep 15, 2025

GPT-5-Codex

Coding-optimized GPT model for repository edits, reviews, and agentic software work.

  • Proprietary
  • Reasoning
  • Tool calling
  • Vision
Capability
—No ECI score yet
Input
$1.25per 1M tokens
Output
$10.00per 1M tokens
Context
400K128K max output
Pricing

What it costs

Input
$1.25per million tokens
Output
$10.00per million tokens
Blended (3:1)
$3.44pricier than 78% of priced models

Typical monthly bills

Monthly usageEstimated cost
Side project2M input + 0.5M output tokens$7.50
Team assistant25M input + 5M output tokens$81.25
Production app250M input + 50M output tokens$812.50

Median of 3 paid API providers on models.dev.

Capability

Independent benchmarks

Epoch AI has not published a Capabilities Index score for GPT-5-Codex yet.

Specifications

The details

Lab
OpenAI
Released
Sep 15, 2025
Knowledge cutoff
Sep 30, 2024
Context window
400,000 tokens
Max output
128,000 tokens
Inputs
Text, Images
Output
Text
Reasoning
Always on
Tool calling
Yes
Structured output
Yes
Weights
Proprietary
Availability
3 API providerslisted on models.dev
Lab-reported

What OpenAI claims

Published by the lab at launch. Settings vary, so compare these only with care.

BenchmarkScoreSettingSource
Artificial Analysis Coding Index38.9 index—Source
SciCode40.9 percent correct—Source
Terminal-Bench Hard37.9 success rate—Source
Same lab

More from OpenAI

Questions

About GPT-5-Codex

How much does GPT-5-Codex cost?

GPT-5-Codex costs $1.25 input / $10.00 output per million tokens (median across 3 API providers). At a 3:1 input-to-output mix that is $3.44 per million tokens, more expensive than 78% of the 360 priced models we track.

What is the context window of GPT-5-Codex?

GPT-5-Codex accepts up to 400,000 tokens per request and can write up to 128,000 tokens in one response.

How good is GPT-5-Codex?

Epoch AI has not published a Capabilities Index score for GPT-5-Codex yet.

Is GPT-5-Codex open source?

No. GPT-5-Codex is proprietary; you use it through an API or partner platforms.

What inputs does GPT-5-Codex support?

GPT-5-Codex accepts text and images and replies in text. It is a reasoning model, supports tool calling and can return structured JSON output.

When was GPT-5-Codex released?

OpenAI released GPT-5-Codex on Sep 15, 2025. Its training data runs to Sep 30, 2024.

What are the best alternatives to GPT-5-Codex?

The closest current models from other labs on capability, price and release date are Gemini 2.5 Computer Use Preview (Google, $1.25 / $10.00), Jamba Large (AI21 Labs, $2.00 / $8.00), Command A Translate (Cohere, $2.50 / $10.00) and Qwen3-Next 80B-A3B (Thinking) (Alibaba (Qwen), $0.50 / $6.00).