Claude Sonnet 4 vs Claude Haiku 3.5

Compare Claude Sonnet 4 and Claude Haiku 3.5: 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 Claude Haiku 3.5
CategoryFrontierCompact
Parameters~500B~20B
Context Window200K200K
Input Price$0.03/1M tokens$0.008/1M tokens
Output Price$0.15/1M tokens$0.04/1M tokens
Latency~350ms~150ms

Choose Claude Sonnet 4 when:

  • ✓ General Q&A
  • ✓ Content generation
  • ✓ Temple chatbots
Key Strengths:

Excellent reasoning-per-dollar, 200K context, Strong multilingual

Choose Claude Haiku 3.5 when:

  • ✓ High-volume APIs
  • ✓ Fast chatbots
  • ✓ Content moderation
Key Strengths:

Very fast, Low cost, 200K context

Verdict: Claude Sonnet 4 vs Claude Haiku 3.5

For cost efficiency, Claude Haiku 3.5 wins at $0.008/1M input tokens. For speed, Claude Haiku 3.5 is faster at ~150ms. Claude Sonnet 4 excels at General Q&A while Claude Haiku 3.5 is better for High-volume APIs. 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 costs $0.03/1M input tokens and $0.15/1M output tokens. Claude Haiku 3.5 costs $0.008 input and $0.04 output. Claude Haiku 3.5 is 3.8x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.

Performance & Context

Claude Sonnet 4 has a 200K context window with ~350ms latency. Claude Haiku 3.5 offers 200K context at ~150ms. Both have identical context windows.

Best For

Claude Sonnet 4 (Frontier) is optimized for: General Q&A, Content generation, Temple chatbots. Claude Haiku 3.5 (Compact) works best for: High-volume APIs, Fast chatbots, Content moderation.

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

# Use Claude Haiku 3.5
response_b = client.chat.completions.create(
    model="claude-haiku-3-5",
    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 Sonnet 4 or Claude Haiku 3.5?

Claude Sonnet 4 (Frontier, ~500B) offers Excellent reasoning-per-dollar. Claude Haiku 3.5 (Compact, ~20B) offers Very fast. Choose Claude Sonnet 4 for General Q&A or Claude Haiku 3.5 for High-volume APIs.

How much does Claude Sonnet 4 cost vs Claude Haiku 3.5?

Claude Sonnet 4: $0.03/1M input, $0.15/1M output. Claude Haiku 3.5: $0.008/1M 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 and Claude Haiku 3.5 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.