Codex CLI vs Opus 4.5
A detailed comparison to help you choose the right AI tool for your needs.
Our Pick
Claude Opus 4.5
Claude Opus 4.5 edges out Codex CLI with superior overall performance and features that make it the better choice for most users.
Try Opus 4.5Feature Comparison
Feature
Codex CLI
Opus 4.5
Ratings
Overall Rating
4.7
4.9
Coding
4.7
5.0
Writing
4.3
4.8
Reasoning
4.5
4.9
Speed
4.6
4.2
Value
4.8
4.5
Pricing
Monthly Price
$20
$20
Free Tier
Input (per 1M tokens)
$2.5
$5
Output (per 1M tokens)
$10
$25
Features
Context Window
128K
200K
Vision/Images
Audio
Video
Code Generation
AI Agents
Codex CLI
Pros
- Open source (Apache 2.0)
- Multimodal input support
- Local-first privacy
- Rich approvals workflow
- Included with ChatGPT subscription
Cons
- Newer tool with evolving features
- Less mature than Claude Code
Claude Opus 4.5
Pros
- Best coding model available (80.9% SWE-bench)
- Excellent for autonomous agents
- Effort parameter allows speed/quality tradeoff
- 76% fewer tokens than Sonnet at same quality
- Strong at long-horizon tasks
Cons
- More expensive than Sonnet
- Slower on simple tasks
- Requires Claude Pro/Max subscription for full access
Choose Codex CLI if you need:
Rapid prototyping, open-source flexibility, ChatGPT users
Choose Opus 4.5 if you need:
Professional developers, complex codebases, autonomous agents
Ready to get started?
Both tools offer free tiers or trials. Try them out and see which one works best for your workflow.