Claude 3.5 vs GPT-4o: Which is Better?

The AI industry's two heavyweight champions are going head-to-head. Anthropic's Claude 3.5 Sonnet and OpenAI's GPT-4o are both priced at $20/month for their premium tiers, making this a genuine apples-to-apples comparison. After months of testing both models extensively, here's our definitive breakdown.

Quick Comparison Table

Here's how the two stack up on key metrics:

Context Window: Claude wins (200K tokens vs 128K for GPT-4o)
Speed: GPT-4o wins (faster response times)
Coding: Claude wins (better at complex refactors)
Creative Writing: Claude wins (more natural prose)
Multimodal: GPT-4o wins (voice, vision, real-time)
Safety/Refusals: Claude is more cautious (sometimes too much)
Up-to-date knowledge: Both have similar knowledge cutoffs

Coding Performance: The Developer's Choice

This is where Claude 3.5 Sonnet truly shines. In our tests across Python, JavaScript, TypeScript, and Rust, Claude consistently:

Produced fewer bugs in first-pass code
Gave cleaner explanations of what it changed and why
Handled larger codebases thanks to its 200K context window
Excelled at refactoring existing code without breaking functionality

GPT-4o is no slouch—it's still a top-tier coding assistant—but Claude's focus on code quality has made it the favorite among developers building AI-native tools like Cursor and Windsurf.

Creative Writing: The Writer's Companion

Ask both models to write a creative story, and you'll notice a difference immediately. Claude's output reads more like human writing—varied sentence structure, natural flow, and less of that "AI polish" that makes text feel sterile.

GPT-4o tends to be more formulaic. Its default style includes a lot of superlatives ("absolutely," "incredibly") and can feel overly enthusiastic. You can prompt it to tone down, but Claude's baseline is just more natural.

Winner for writers: Claude, especially for long-form content like newsletters, blog posts, and books.

Multimodal Capabilities: GPT-4o's Domain

If you need more than just text, GPT-4o is the clear winner:

Real-time Voice Mode: GPT-4o has an unbelievably natural voice conversation feature. It can hear you, respond with emotion, and even laugh. Claude has no equivalent.
Vision: Both can analyze images, but GPT-4o is integrated into the ChatGPT app with seamless camera access.
Canvas Mode: GPT-4o's new Canvas feature lets you collaborate on documents and code side-by-side with the AI.

Claude's Artifacts feature is a partial competitor—it can generate interactive code previews—but it's not as polished as Canvas.

Speed and Latency

GPT-4o is noticeably faster. OpenAI has heavily optimized their infrastructure, and responses feel snappier. Claude 3.5 Sonnet is still fast (much faster than the old Claude 2), but there's a perceptible difference, especially for short queries.

Safety and "Refusals"

Both companies prioritize safety, but they've made different tradeoffs:

Claude errs on the side of caution. It sometimes refuses creative writing prompts involving conflict, violence, or even mildly controversial topics. This can be frustrating for fiction writers.

GPT-4o is more permissive by default but has been known to change behavior suddenly with silent policy updates, which can break workflows.

Pricing and Value

Both cost $20/month for their pro tiers (ChatGPT Plus and Claude Pro). At this price point, the value is exceptional for either. Claude Pro offers significantly more usage than the free tier, while ChatGPT Plus includes GPT-4o, DALL-E 3, and plugins.

For API users, pricing varies by token usage. Claude is often slightly cheaper for large-context workloads due to its efficient architecture.

The Verdict: Which Should You Choose?

Choose Claude 3.5 Sonnet if:

You're a developer who needs a coding partner
You work with large documents or codebases (200K context)
You value natural-sounding writing
You use API-focused workflows

Choose GPT-4o if:

You need voice or real-time conversation features
You want an all-in-one ecosystem (images, plugins, Canvas)
You prioritize speed over context length
You're already invested in the OpenAI ecosystem

The honest answer? Many power users subscribe to both. At $20/month each, having access to the best of both worlds is a small price for anyone whose work depends on AI.