Claude Sonnet 4.5 vs GPT-5

API pricing, context window and capabilities for Claude Sonnet 4.5 and GPT-5, side by side. Prices are the cheapest serving route per 1M tokens, verified against LiteLLM and OpenRouter.

Verdict

computed from the published numbers

Claude Sonnet 4.5 wins on context window. GPT-5 wins on price. Benchmark data is unavailable for one or both models.

Price
GPT-5
Coding
Not called
Intelligence
Not called
Context window
Claude Sonnet 4.5

Key takeaways

who wins on what, from the published numbers

Claude Sonnet 4.5 wins

  • Larger context window (1M vs 410K)
  • Higher max output (1M vs 128K)
  • More serving providers (8 vs 6)

GPT-5 wins

  • Cheaper input ($3.00 vs $1.25 /1M)
  • Cheaper output ($15.00 vs $10.00 /1M)
  • Has web search
Cheaper overall
GPT-5
$1.25 + $10.00 /1M
Larger context
Claude Sonnet 4.5
1M
More providers
Claude Sonnet 4.5
8 providers

Pricing & specs

cheapest serving route · per 1M tokens
Claude Sonnet 4.5GPT-5
Input $/1M$3.00 $1.25 best
Output $/1M$15.00 $10.00 best
Context window1M best410K
Max output1M best128K
Serving providers8 best6
Released2025-09-29 2025-08-07

Benchmarks

Artificial Analysis indices, side by side
Claude Sonnet 4.5GPT-5
IntelligenceNot available 34.7
CodingNot available 37.8
GPQA DiamondNot available 85%
Output speedNot available 69 t/s
Latency (TTFT)Not available 33.91s

Cost calculator

choose a serving route for each side
Input tokens / month
Output tokens / month
Claude Sonnet 4.5
via Databricks
$30
GPT-5
via Databricks
$16

Capabilities

feature support, side by side
FeatureClaude Sonnet 4.5GPT-5
Vision
Tool use
Reasoning
Audio
Prompt caching
Structured output
Web search

Related comparisons

Frequently asked questions

Which is cheaper, Claude Sonnet 4.5 or GPT-5?
GPT-5 is cheaper for input ($3.00 vs $1.25 per 1M tokens). GPT-5 is cheaper for output ($15.00 vs $10.00 per 1M tokens).
What is the context window difference between Claude Sonnet 4.5 and GPT-5?
Claude Sonnet 4.5 has a 1M-token context window and GPT-5 has 410K tokens, so Claude Sonnet 4.5 can take a larger prompt.
Pricing verified against LiteLLM + OpenRouter + provider pages · refreshed daily

Every weekday

AI moves fast. Here's your debrief.

News, analysis, tools, and more.

For people who build with AI