# GPT-5 Codex Review & Benchmarks (2026): Price, Context, Specs | Alher Tech

> GPT-5 Codex by OpenAI: benchmarks, pricing, context window, strengths and use cases. Data from official benchmark sources.

- Canonical page: https://alhertech.com/en/ai-comparison/gpt-5-codex/
- Site: Alher Tech (custom software, AI agents and SEO engineering, https://alhertech.com/)
- Contact: https://alhertech.com/en/contact/

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Last updated: April 22, 2026

## Specs

- **Vendor**: OpenAI
- **Released**: September 15, 2025
- **Context window**: 400K tokens
- **Input**: $8 / M tokens
- **Output**: $32 / M tokens

## Benchmarks

- **mmlu**: 87.2
- **gpqa**: 58.4
- **humanEval**: 94.8
- **arenaElo**: 1395
- **sweBench**: 68
- **sweBenchPro**: 60
- **liveCodeBench**: 82
- **aiderPolyglot**: 82
- **terminalBench**: 50
- **mmluPro**: 80
- **hle**: 16
- **aime**: 85
- **math500**: 94

## Strengths

- Specialized coding fork of GPT-5: top HumanEval
- Long-horizon agentic coding up to 7 hours
- Powers Codex CLI and Codex cloud by default

## Weaknesses

- Not built for multimodal or general chat
- Lower GPQA than GPT-5 on non-code reasoning
- Overkill for simple autocomplete tasks

## Best for

- Autonomous coding agents
- PR generation and multi-file refactors
- IDE copilots that need GPT-5-class coding

[Compare with other AI models](https://alhertech.com/en/ai-comparison/)