Claude Opus 4 vs Phi-3.5 Mini

Compare Claude Opus 4 and Phi-3.5 Mini: 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 Opus 4 Phi-3.5 Mini
CategoryFrontierCompact
Parameters~2T3.8B
Context Window200K128K
Input Price$0.15/1M tokens$0.005/1M tokens
Output Price$0.75/1M tokens$0.01/1M tokens
Latency~800ms~50ms

Choose Claude Opus 4 when:

  • ✓ Complex counseling
  • ✓ Detailed chart analysis
  • ✓ Enterprise reports
Key Strengths:

Deepest reasoning, Exceptional nuance, Best complex analysis

Choose Phi-3.5 Mini when:

  • ✓ Simple Q&A
  • ✓ Classification
  • ✓ Edge inference
Key Strengths:

128K context in tiny model, Ultra-low cost, Fast

Verdict: Claude Opus 4 vs Phi-3.5 Mini

For cost efficiency, Phi-3.5 Mini wins at $0.005/1M input tokens. For speed, Phi-3.5 Mini is faster at ~50ms. Claude Opus 4 excels at Complex counseling while Phi-3.5 Mini is better for Simple Q&A. 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 Opus 4 costs $0.15/1M input tokens and $0.75/1M output tokens. Phi-3.5 Mini costs $0.005 input and $0.01 output. Phi-3.5 Mini is 30.0x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.

Performance & Context

Claude Opus 4 has a 200K context window with ~800ms latency. Phi-3.5 Mini offers 128K context at ~50ms. Claude Opus 4 has the larger context window.

Best For

Claude Opus 4 (Frontier) is optimized for: Complex counseling, Detailed chart analysis, Enterprise reports. Phi-3.5 Mini (Compact) works best for: Simple Q&A, Classification, Edge inference.

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 Opus 4
response_a = client.chat.completions.create(
    model="claude-opus-4",
    messages=[{"role": "user", "content": "Your question here"}]
)

# Use Phi-3.5 Mini
response_b = client.chat.completions.create(
    model="phi-3-5-mini",
    messages=[{"role": "user", "content": "Your question here"}]
)

Start Building with XALEN

200+ AI models. One API. Pay-as-you-go.

Get API Key Try in Playground

Frequently Asked Questions

Which is better, Claude Opus 4 or Phi-3.5 Mini?

Claude Opus 4 (Frontier, ~2T) offers Deepest reasoning. Phi-3.5 Mini (Compact, 3.8B) offers 128K context in tiny model. Choose Claude Opus 4 for Complex counseling or Phi-3.5 Mini for Simple Q&A.

How much does Claude Opus 4 cost vs Phi-3.5 Mini?

Claude Opus 4: $0.15/1M input, $0.75/1M output. Phi-3.5 Mini: $0.005/1M input, $0.01/1M 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 Opus 4 and Phi-3.5 Mini 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.