Model
Model explorer

GPT-5-Codex

CLOSED
OpenAI · GPT-5 family · released Sep 15, 2025

GPT-5 optimized for agentic coding; can run autonomously for hours inside Codex.

ReasoningCodingVisionFunction callingTool useAgentic
2103.4
Elo · unrated
Parameters
Undisclosed
Active params
—
Context
400K tokens
Architecture
GPT-5 fine-tuned for agentic software engineering with dynamic thinking-time scaling; dense transformer, exact size undisclosed
License
Proprietary (OpenAI API Terms)
Languages
—
API price (in/out)
$1.25 / $10
Modalities
text · vision
Benchmark results
Bar shows position within the tracked field; marker = field best
SWE-bench VerifiedCoding74.5%#44
best: Claude Fable 5 · 95.0%
Run it locally
Closed weights — available via API only. No local deployment.
Input / M tok
$1.25
Output / M tok
$10
GPT-5 family
Elo progression across releases
GPT-5Aug 20252082.7GPT-5 miniAug 20251873.5GPT-5 nanoAug 20251595.3GPT-5 ProAug 20252349.9GPT-5-CodexSep 20252103.4
Resources
DOCSdevelopers.openai.com/api/docs/models/gpt-5-codexAPIAvailable via OpenAI API
API price $1.25/$10 · each benchmark row carries its own source badge (see methodology)