Llama 3.1 405B vs StarCoder2 15B

Compare Llama 3.1 405B and StarCoder2 15B: pricing, performance, context window, latency, and best use cases. Side-by-side comparison on XALEN.

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

All Meta models All BigCode models What is an LLM API? Python Quickstart What is inference?
Feature Llama 3.1 405B StarCoder2 15B
CategoryOpen SourceCode
Parameters405B15B
Context Window128K16K
Input Price$0.08/1M tokens$0.02/1M tokens
Output Price$0.14/1M tokens$0.03/1M tokens
Latency~600ms~150ms

Choose Llama 3.1 405B when:

  • ✓ Premium tasks
  • ✓ Research
  • ✓ Fine-tuning base
Key Strengths:

Largest open model, Highest open-source quality

Choose StarCoder2 15B when:

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

Strong coding, 600+ languages, Open weights

Verdict: Llama 3.1 405B vs StarCoder2 15B

For cost efficiency, StarCoder2 15B wins at $0.02/1M input tokens. For speed, StarCoder2 15B is faster at ~150ms. Llama 3.1 405B excels at Premium tasks while StarCoder2 15B is better for Code completion. Both are available on XALEN through a single API — try them in the Playground to see which fits your workload.

Detailed Analysis

Pricing Comparison

Llama 3.1 405B costs $0.08/1M input tokens and $0.14/1M output tokens. StarCoder2 15B costs $0.02 input and $0.03 output. StarCoder2 15B is 4.0x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.

Performance & Context

Llama 3.1 405B has a 128K context window with ~600ms latency. StarCoder2 15B offers 16K context at ~150ms. Llama 3.1 405B has the larger context window.

Best For

Llama 3.1 405B (Open Source) is optimized for: Premium tasks, Research, Fine-tuning base. StarCoder2 15B (Code) works best for: Code completion, Code generation, Bug fixing.

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 Llama 3.1 405B
response_a = client.chat.completions.create(
    model="llama-3-1-405b",
    messages=[{"role": "user", "content": "Your question here"}]
)

# Use StarCoder2 15B
response_b = client.chat.completions.create(
    model="starcoder2-15b",
    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, Llama 3.1 405B or StarCoder2 15B?

Llama 3.1 405B (Open Source, 405B) offers Largest open model. StarCoder2 15B (Code, 15B) offers Strong coding. Choose Llama 3.1 405B for Premium tasks or StarCoder2 15B for Code completion.

How much does Llama 3.1 405B cost vs StarCoder2 15B?

Llama 3.1 405B: $0.08/1M input, $0.14/1M output. StarCoder2 15B: $0.02/1M input, $0.03/1M 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 Llama 3.1 405B and StarCoder2 15B 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.