Updated February 2026

Sonnet 4.5 vs GPT-5.4

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

Anthropic

Claude Sonnet 4.5

4.8
Try Sonnet 4.5 Free
Winner
OpenAI

GPT-5.4 Thinking

5.0
Try GPT-5.4 Free

Quick Verdict: Sonnet 4.5 vs GPT-5.4

After extensive testing, **GPT-5.4 Thinking** comes out ahead with a 5.0/5 rating. It's the better choice for most users, especially those focused on Complex reasoning, agentic coding, long-document analysis, multi-step workflows. However, Claude Sonnet 4.5 remains competitive and may be preferable if you prioritize Daily coding tasks, writing, general use.

Our Pick for 2026
GPT-5.4 Thinking

GPT-5.4 Thinking edges out Claude Sonnet 4.5 with superior overall performance and features that make it the better choice for most users in 2026. With a 5.0/5 rating, it excels particularly in Complex reasoning, agentic coding, long-document analysis, multi-step workflows.

Try GPT-5.4 Free

Feature Comparison Table

Side-by-side comparison of key features and capabilities

Feature
Sonnet 4.5
GPT-5.4
Performance Ratings
Overall Rating
4.8
5.0
Coding
4.7
4.8
Writing
4.9
4.6
Reasoning
4.7
5.0
Speed
4.6
3.9
Value for Money
4.9
4.3
Pricing
Monthly Price
$20
$200
Free Tier
Input (per 1M tokens)
$3
$2.5
Output (per 1M tokens)
$15
$15
Capabilities
Context Window
200K
1000K
Vision/Images
Audio
Video
Code Generation
AI Agents

When to Use Sonnet 4.5 vs GPT-5.4

Choose Sonnet 4.5 When You Need:

  • Daily coding tasks, writing, general use
  • Better quality content writing and creative tasks
  • Faster response times for time-sensitive work
  • Testing capabilities with a free tier before committing

Choose GPT-5.4 When You Need:

  • Complex reasoning, agentic coding, long-document analysis, multi-step workflows
  • Superior coding assistance and code generation
  • Processing longer documents with 1000K context

In-Depth Analysis: Sonnet 4.5 vs GPT-5.4

Performance & Capabilities

In our comprehensive testing for 2026, we evaluated both Claude Sonnet 4.5 and GPT-5.4 Thinking across multiple dimensions including coding tasks, creative writing, reasoning problems, and general conversation quality. GPT-5.4 Thinking emerged as our top pick with an overall rating of 5.0/5.

Claude Sonnet 4.5 scored 4.7/5 on coding tasks, making it an excellent choice for developers. In comparison, GPT-5.4 Thinking achieved 4.8/5 in this category.

Pricing & Value

When it comes to pricing, Claude Sonnet 4.5 has an advantage with its free tier. For paid plans, Claude Sonnet 4.5 is more affordable at $20/month compared to $200/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.

GPT-5.4 Thinking, on the other hand, excels at Complex reasoning, agentic coding, long-document analysis, multi-step workflows. Users who prioritize 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

GPT-5.4 Thinking Pros & Cons

Pros

  • 1M token context window — largest from OpenAI
  • 33% fewer false claims vs GPT-5.2
  • Built-in computer-use capabilities
  • Intervene mid-response during reasoning
  • 6x cheaper input tokens than GPT-5.2 Thinking
  • Excellent for coding, agentic workflows, and document analysis

Cons

  • Requires Pro subscription ($200/mo) for full access
  • Slower than non-thinking variants
  • Can be overkill for simple tasks
  • Writing still not as natural as Claude

Best For: Sonnet 4.5

Daily coding tasks, writing, general use

Best For: GPT-5.4

Complex reasoning, agentic coding, long-document analysis, multi-step workflows

Frequently Asked Questions

Common questions about Sonnet 4.5 vs GPT-5.4

Is Claude Sonnet 4.5 better than GPT-5.4 Thinking in 2026?

Based on our benchmarks and analysis, GPT-5.4 Thinking performs better overall with a rating of 5.0/5. However, the best choice depends on your specific needs - Claude Sonnet 4.5 excels at Daily coding tasks, writing, general use, while GPT-5.4 Thinking is better for Complex reasoning, agentic coding, long-document analysis, multi-step workflows.

What is the price difference between Sonnet 4.5 and GPT-5.4?

Claude Sonnet 4.5 offers a free tier and costs $20/month for paid plans. GPT-5.4 Thinking costs $200/month for paid plans.

Which is better for coding: Sonnet 4.5 or GPT-5.4?

For coding tasks, GPT-5.4 Thinking scores higher with a 4.8/5 coding rating compared to 4.7/5.

Can I use Sonnet 4.5 and GPT-5.4 for free?

Claude Sonnet 4.5 does offer a free tier with limited features. GPT-5.4 Thinking requires a paid subscription. Both tools offer trial periods or limited free access for new users.

Which AI has a larger context window: Sonnet 4.5 or GPT-5.4?

GPT-5.4 Thinking has a larger context window at 1,000,000 tokens, compared to 200,000 tokens. Larger context windows allow processing more text in a single conversation.

Is Sonnet 4.5 faster than GPT-5.4?

In our speed tests, Claude Sonnet 4.5 is faster with a speed rating of 4.6/5. Response times can vary based on server load and query complexity.

Which is better for writing content: Sonnet 4.5 or GPT-5.4?

For content writing, Claude Sonnet 4.5 excels with a writing rating of 4.9/5 versus 4.6/5. Consider your specific writing needs when choosing.

Do Sonnet 4.5 and GPT-5.4 support image generation?

Claude Sonnet 4.5 supports image understanding and analysis. GPT-5.4 Thinking supports image understanding and analysis. For dedicated image generation, consider specialized tools like DALL-E or Midjourney.

Which AI should beginners choose: Sonnet 4.5 or GPT-5.4?

For beginners, we recommend Claude Sonnet 4.5 since it offers a free tier. GPT-5.4 Thinking has a slightly better overall user experience based on our testing.

Can I switch from Sonnet 4.5 to GPT-5.4 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 GPT-5.4 Thinking for Complex reasoning, agentic coding, long-document analysis, multi-step workflows.

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.