Claude 4.5 vs GPT-5.1

Which AI writes better code in 2025?

Last updated: November 2025 • Based on real benchmark data

The Verdict (TL;DR)

Claude 4.5 leads in coding benchmarks (77.2% vs 76.3% on SWE-bench) and excels at complex refactoring tasks.

GPT-5.1 is faster, cheaper, and better for general-purpose tasks beyond coding.

Bottom line: For serious coding work, Claude 4.5 has the edge. For mixed workloads or budget constraints, GPT-5.1 is competitive.

Performance Benchmarks

BenchmarkClaude 4.5GPT-5.1Winner
SWE-bench Verified
Real GitHub bug fixes
77.2%76.3%Claude
AIME 2025
Advanced math problems
94.0%GPT-5.1
OSWorld
Computer control tasks
61.4%Claude
Response Speed
Average tokens/sec
~45 t/s~70 t/sGPT-5.1

Pricing Breakdown

Claude 4.5 Sonnet

Input$3 / 1M tokens
Output$15 / 1M tokens

Higher cost but best-in-class coding performance

GPT-5.1

Input$2.50 / 1M tokens
Output$10 / 1M tokens

More affordable with competitive performance

Strengths & Weaknesses

Claude 4.5

Strengths

  • • Highest SWE-bench score ever (77.2%)
  • • Better at complex refactoring
  • • More reliable code structure
  • • Better at following coding style guides

Weaknesses

  • • Slower response times
  • • Higher API costs
  • • Smaller ecosystem (fewer integrations)

GPT-5.1

Strengths

  • • Faster response times (~70 t/s)
  • • Lower cost per token
  • • Huge ecosystem (ChatGPT, API, plugins)
  • • Better at general reasoning

Weaknesses

  • • Slightly lower coding benchmark scores
  • • Occasional hallucinations in edge cases
  • • Less consistent code formatting

Which Should You Choose?

Choose Claude 4.5 if you...

  • • Work on complex refactoring projects
  • • Need the absolute best code quality
  • • Use AI to review or improve existing code
  • • Work with large codebases (high context understanding)
  • • Can afford premium pricing for better results

Choose GPT-5.1 if you...

  • • Need fast iteration speed
  • • Want lower API costs
  • • Use AI for mixed tasks (coding + writing + reasoning)
  • • Need extensive integrations (ChatGPT ecosystem)
  • • Work on smaller, well-defined coding tasks

What About Claude 5?

Claude 5 is expected in Q2-Q3 2026. Track the release and get instant alerts.

Back to Claude 5 Hub

Data Sources & Verification

  • • SWE-bench Verified: Anthropic official announcement (Sep 2025), OpenAI System Card (Nov 2025)
  • • AIME 2025: OpenAI research paper
  • • OSWorld: Anthropic benchmark results
  • • Pricing: Official API pricing pages (Nov 2025)
  • • Performance tests: Axis Intelligence, artificialanalysis.ai