StarCoder2 15B vs Claude 3.5 Sonnet (Thinking)

Compare StarCoder2 15B and Claude 3.5 Sonnet (Thinking): 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 StarCoder2 15B Claude 3.5 Sonnet (Thinking)
CategoryCodeReasoning
Parameters15B~500B
Context Window16K200K
Input Price$0.02/1M tokens$0.03/1M tokens
Output Price$0.03/1M tokens$0.15/1M tokens
Latency~150ms~600ms

Choose StarCoder2 15B when:

  • ✓ Code completion
  • ✓ Code generation
  • ✓ Bug fixing
Key Strengths:

Strong coding, 600+ languages, Open weights

Choose Claude 3.5 Sonnet (Thinking) when:

  • ✓ Complex analysis
  • ✓ Multi-step logic
  • ✓ Verification tasks
Key Strengths:

Transparent thinking, Strong reasoning, Self-correction

Verdict: StarCoder2 15B vs Claude 3.5 Sonnet (Thinking)

For cost efficiency, StarCoder2 15B wins at $0.02/1M input tokens. For speed, StarCoder2 15B is faster at ~150ms. StarCoder2 15B excels at Code completion while Claude 3.5 Sonnet (Thinking) is better for Complex analysis. Both are available on XALEN through a single API — try them in the Playground to see which fits your workload.

Detailed Analysis

Pricing Comparison

StarCoder2 15B costs $0.02/1M input tokens and $0.03/1M output tokens. Claude 3.5 Sonnet (Thinking) costs $0.03 input and $0.15 output. StarCoder2 15B is 1.5x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.

Performance & Context

StarCoder2 15B has a 16K context window with ~150ms latency. Claude 3.5 Sonnet (Thinking) offers 200K context at ~600ms. Claude 3.5 Sonnet (Thinking) has the larger context window.

Best For

StarCoder2 15B (Code) is optimized for: Code completion, Code generation, Bug fixing. Claude 3.5 Sonnet (Thinking) (Reasoning) works best for: Complex analysis, Multi-step logic, Verification tasks.

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 StarCoder2 15B
response_a = client.chat.completions.create(
    model="starcoder2-15b",
    messages=[{"role": "user", "content": "Your question here"}]
)

# Use Claude 3.5 Sonnet (Thinking)
response_b = client.chat.completions.create(
    model="claude-3-5-sonnet-thinking",
    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, StarCoder2 15B or Claude 3.5 Sonnet (Thinking)?

StarCoder2 15B (Code, 15B) offers Strong coding. Claude 3.5 Sonnet (Thinking) (Reasoning, ~500B) offers Transparent thinking. Choose StarCoder2 15B for Code completion or Claude 3.5 Sonnet (Thinking) for Complex analysis.

How much does StarCoder2 15B cost vs Claude 3.5 Sonnet (Thinking)?

StarCoder2 15B: $0.02/1M input, $0.03/1M output. Claude 3.5 Sonnet (Thinking): $0.03/1M input, $0.15/1M 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 StarCoder2 15B and Claude 3.5 Sonnet (Thinking) 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.