Codex CLI vs Grammarly
A detailed comparison to help you choose the right AI tool for your needs.
Our Pick
Codex CLI
Codex CLI edges out Grammarly with superior overall performance and features that make it the better choice for most users.
Try Codex CLIFeature Comparison
Feature
Codex CLI
Grammarly
Ratings
Overall Rating
4.7
4.6
Coding
4.7
-
Writing
4.3
4.8
Reasoning
4.5
4.0
Speed
4.6
5.0
Value
4.8
4.5
Pricing
Monthly Price
$20
$12
Free Tier
Input (per 1M tokens)
$2.5
-
Output (per 1M tokens)
$10
-
Features
Context Window
128K
50K
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
Grammarly
Pros
- Works everywhere (browser, desktop, mobile)
- Excellent grammar and spelling
- Tone detection
- Plagiarism checker
- GrammarlyGO AI assistant
Cons
- Not for creative writing
- Premium features require subscription
- Can be overly corrective
Choose Codex CLI if you need:
Rapid prototyping, open-source flexibility, ChatGPT users
Choose Grammarly if you need:
Grammar checking, professional emails, academic writing
Ready to get started?
Both tools offer free tiers or trials. Try them out and see which one works best for your workflow.