GPT-5.2 o1 vs Grammarly

A detailed comparison to help you choose the right AI tool for your needs.

Winner
OpenAI

GPT-5.2 Thinking

4.9
Try GPT-5.2 o1
Grammarly

Grammarly

4.6
Try Grammarly
Our Pick
GPT-5.2 Thinking

GPT-5.2 Thinking edges out Grammarly with superior overall performance and features that make it the better choice for most users.

Try GPT-5.2 o1

Feature Comparison

Feature
GPT-5.2 o1
Grammarly
Ratings
Overall Rating
4.9
4.6
Coding
4.8
-
Writing
4.5
4.8
Reasoning
5.0
4.0
Speed
3.8
5.0
Value
4.0
4.5
Pricing
Monthly Price
$200
$12
Free Tier
Input (per 1M tokens)
$15
-
Output (per 1M tokens)
$60
-
Features
Context Window
128K
50K
Vision/Images
Audio
Video
Code Generation
AI Agents

GPT-5.2 Thinking

Pros

  • Best reasoning model from OpenAI
  • Edges out Gemini 3 and Claude Opus 4.5 on most tests
  • Performs at/above human expert level on GDPval
  • Excellent for coding, math, and document analysis
  • State-of-the-art on SWE-Bench Pro

Cons

  • Expensive ($200/mo for Pro subscription)
  • Slower than Instant variant
  • Requires Pro subscription for full access
  • Writing can feel robotic

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 GPT-5.2 o1 if you need:

Complex reasoning, software engineering, research, math proofs

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.