Claude Sonnet 4.5 vs Inflection 3 Pi

Compare Claude Sonnet 4.5 and Inflection 3 Pi: pricing, performance, context window, latency, and best use cases. Side-by-side comparison on XALEN.

Updated 2026-05-21 · By Abhishek Raj · Our methodology

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Feature Claude Sonnet 4.5 Inflection 3 Pi
CategoryFrontierCompact
Parameters~600B~40B
Context Window200K128K
Input Price$0.03/1M tokens$0.02/1M tokens
Output Price$0.15/1M tokens$0.04/1M tokens
Latency~350ms~150ms

Choose Claude Sonnet 4.5 when:

  • ✓ Code generation
  • ✓ Structured output
  • ✓ Automation
Key Strengths:

Strong coding, Better instruction following, Reliable

Choose Inflection 3 Pi when:

  • ✓ Personal assistants
  • ✓ Chat companions
  • ✓ Support bots
Key Strengths:

Conversational, Empathetic, Fast

Verdict: Claude Sonnet 4.5 vs Inflection 3 Pi

For cost efficiency, Inflection 3 Pi wins at $0.02/1M input tokens. For speed, Inflection 3 Pi is faster at ~150ms. Claude Sonnet 4.5 excels at Code generation while Inflection 3 Pi is better for Personal assistants. Both are available on XALEN through a single API — try them in the Playground to see which fits your workload.

Detailed Analysis

Pricing Comparison

Claude Sonnet 4.5 costs $0.03/1M input tokens and $0.15/1M output tokens. Inflection 3 Pi costs $0.02 input and $0.04 output. Inflection 3 Pi is 1.5x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.

Performance & Context

Claude Sonnet 4.5 has a 200K context window with ~350ms latency. Inflection 3 Pi offers 128K context at ~150ms. Claude Sonnet 4.5 has the larger context window.

Best For

Claude Sonnet 4.5 (Frontier) is optimized for: Code generation, Structured output, Automation. Inflection 3 Pi (Compact) works best for: Personal assistants, Chat companions, Support bots.

Try Both on XALEN

Both models are available through XALEN's OpenAI-compatible API. Switch between them by changing the model parameter:

from xalen import XALEN

client = XALEN(api_key="xln_test_YOUR_KEY")

# Use Claude Sonnet 4.5
response_a = client.chat.completions.create(
    model="claude-sonnet-4-5",
    messages=[{"role": "user", "content": "Your question here"}]
)

# Use Inflection 3 Pi
response_b = client.chat.completions.create(
    model="inflection-3-pi",
    messages=[{"role": "user", "content": "Your question here"}]
)

Start Building with XALEN

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Get API Key Try in Playground

Frequently Asked Questions

Which is better, Claude Sonnet 4.5 or Inflection 3 Pi?

Claude Sonnet 4.5 (Frontier, ~600B) offers Strong coding. Inflection 3 Pi (Compact, ~40B) offers Conversational. Choose Claude Sonnet 4.5 for Code generation or Inflection 3 Pi for Personal assistants.

How much does Claude Sonnet 4.5 cost vs Inflection 3 Pi?

Claude Sonnet 4.5: $0.03/1M input, $0.15/1M output. Inflection 3 Pi: $0.02/1M input, $0.04/1M output. Both available on XALEN with batch processing at 50% discount.

Can I use both models on XALEN?

Yes. XALEN provides 200+ models through a single OpenAI-compatible API. Switch between Claude Sonnet 4.5 and Inflection 3 Pi by changing the model parameter. No code changes needed.

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Last updated: 2026-05-21. Pricing and specifications may change. Check pricing page for latest rates.