Updated January 2026

Sonnet 4.5 vs Grammarly

A comprehensive 2026 comparison to help you choose the right AI tool for your needs. We tested both extensively.

Winner
Anthropic

Claude Sonnet 4.5

4.8
Try Sonnet 4.5 Free
Grammarly

Grammarly

4.6
Try Grammarly Free

Quick Verdict: Sonnet 4.5 vs Grammarly

After extensive testing, **Claude Sonnet 4.5** comes out ahead with a 4.8/5 rating. It's the better choice for most users, especially those focused on Daily coding tasks, writing, general use. However, Grammarly remains competitive and may be preferable if you prioritize Grammar checking, professional emails, academic writing.

Our Pick for 2026
Claude Sonnet 4.5

Claude Sonnet 4.5 edges out Grammarly with superior overall performance and features that make it the better choice for most users in 2026. With a 4.8/5 rating, it excels particularly in Daily coding tasks, writing, general use.

Try Sonnet 4.5 Free

Feature Comparison Table

Side-by-side comparison of key features and capabilities

Feature
Sonnet 4.5
Grammarly
Performance Ratings
Overall Rating
4.8
4.6
Coding
4.7
-
Writing
4.9
4.8
Reasoning
4.7
4.0
Speed
4.6
5.0
Value for Money
4.9
4.5
Pricing
Monthly Price
$20
$12
Free Tier
Input (per 1M tokens)
$3
-
Output (per 1M tokens)
$15
-
Capabilities
Context Window
200K
50K
Vision/Images
Audio
Video
Code Generation
AI Agents

When to Use Sonnet 4.5 vs Grammarly

Choose Sonnet 4.5 When You Need:

  • Daily coding tasks, writing, general use
  • Superior coding assistance and code generation
  • Better quality content writing and creative tasks
  • Processing longer documents with 200K context
  • Testing capabilities with a free tier before committing

Choose Grammarly When You Need:

  • Grammar checking, professional emails, academic writing
  • Faster response times for time-sensitive work
  • Testing capabilities with a free tier before committing

In-Depth Analysis: Sonnet 4.5 vs Grammarly

Performance & Capabilities

In our comprehensive testing for 2026, we evaluated both Claude Sonnet 4.5 and Grammarly across multiple dimensions including coding tasks, creative writing, reasoning problems, and general conversation quality. Claude Sonnet 4.5 emerged as our top pick with an overall rating of 4.8/5.

Claude Sonnet 4.5 scored 4.7/5 on coding tasks, making it an excellent choice for developers. In comparison, Grammarly also performs well in this category.

Pricing & Value

When it comes to pricing, both tools offer free tiers, making them accessible for testing. For paid plans, Grammarly is more affordable at $12/month compared to $20/month.

Use Cases & Target Audience

Claude Sonnet 4.5 is particularly well-suited for Daily coding tasks, writing, general use. Its strengths make it ideal for professionals who need advanced coding help, quality content creation, and reliable AI assistance.

Grammarly, on the other hand, excels at Grammar checking, professional emails, academic writing. Users who prioritize fast response times, complex reasoning, will find it particularly valuable.

Claude Sonnet 4.5 Pros & Cons

Pros

  • Best value for money
  • Excellent writing quality
  • Fast response times
  • Strong coding abilities
  • Free tier available

Cons

  • Not as powerful as Opus for complex tasks
  • Usage limits on free tier

Grammarly Pros & Cons

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

Best For: Sonnet 4.5

Daily coding tasks, writing, general use

Best For: Grammarly

Grammar checking, professional emails, academic writing

Frequently Asked Questions

Common questions about Sonnet 4.5 vs Grammarly

Is Claude Sonnet 4.5 better than Grammarly in 2026?

Based on our benchmarks and analysis, Claude Sonnet 4.5 performs better overall with a rating of 4.8/5. However, the best choice depends on your specific needs - Claude Sonnet 4.5 excels at Daily coding tasks, writing, general use, while Grammarly is better for Grammar checking, professional emails, academic writing.

What is the price difference between Sonnet 4.5 and Grammarly?

Claude Sonnet 4.5 offers a free tier and costs $20/month for paid plans. Grammarly offers a free tier and costs $12/month for paid plans.

Which is better for coding: Sonnet 4.5 or Grammarly?

Both tools can assist with coding tasks. Check our detailed comparison above to see benchmark results.

Can I use Sonnet 4.5 and Grammarly for free?

Claude Sonnet 4.5 does offer a free tier with limited features. Grammarly does offer a free tier with limited features. Both tools offer trial periods or limited free access for new users.

Which AI has a larger context window: Sonnet 4.5 or Grammarly?

Claude Sonnet 4.5 has a larger context window at 200,000 tokens, compared to 50,000 tokens. Larger context windows allow processing more text in a single conversation.

Is Sonnet 4.5 faster than Grammarly?

In our speed tests, Grammarly is faster with a speed rating of 5.0/5. Response times can vary based on server load and query complexity.

Which is better for writing content: Sonnet 4.5 or Grammarly?

For content writing, Claude Sonnet 4.5 excels with a writing rating of 4.9/5 versus 4.8/5. Consider your specific writing needs when choosing.

Do Sonnet 4.5 and Grammarly support image generation?

Claude Sonnet 4.5 supports image understanding and analysis. Grammarly does not have built-in image capabilities. For dedicated image generation, consider specialized tools like DALL-E or Midjourney.

Which AI should beginners choose: Sonnet 4.5 or Grammarly?

For beginners, we recommend starting with either - both offer free tiers to experiment. Claude Sonnet 4.5 has a slightly better overall user experience based on our testing.

Can I switch from Sonnet 4.5 to Grammarly easily?

Yes, switching between AI tools is straightforward since they use similar prompting interfaces. Your conversation history won't transfer, but you can export important outputs. Many professionals use both tools depending on the task - Claude Sonnet 4.5 for Daily coding tasks, writing, general use and Grammarly for 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 in 2026.