Llama 3.1 405B vs MythoMax 13B

Compare Llama 3.1 405B and MythoMax 13B: 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 Gryphe models What is an LLM API? Python Quickstart What is inference?
Feature Llama 3.1 405B MythoMax 13B
CategoryOpen SourceOpen Source
Parameters405B13B
Context Window128K4K
Input Price$0.08/1M tokens$0.01/1M tokens
Output Price$0.14/1M tokens$0.02/1M tokens
Latency~600ms~100ms

Choose Llama 3.1 405B when:

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

Largest open model, Highest open-source quality

Choose MythoMax 13B when:

  • ✓ Story generation
  • ✓ Creative content
  • ✓ Interactive fiction
Key Strengths:

Creative writing, Roleplay, Narrative quality

Verdict: Llama 3.1 405B vs MythoMax 13B

For cost efficiency, MythoMax 13B wins at $0.01/1M input tokens. For speed, MythoMax 13B is faster at ~100ms. Llama 3.1 405B excels at Premium tasks while MythoMax 13B is better for Story generation. 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. MythoMax 13B costs $0.01 input and $0.02 output. MythoMax 13B is 8.0x 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. MythoMax 13B offers 4K context at ~100ms. 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. MythoMax 13B (Open Source) works best for: Story generation, Creative content, Interactive fiction.

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 MythoMax 13B
response_b = client.chat.completions.create(
    model="mythomax-13b",
    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 MythoMax 13B?

Llama 3.1 405B (Open Source, 405B) offers Largest open model. MythoMax 13B (Open Source, 13B) offers Creative writing. Choose Llama 3.1 405B for Premium tasks or MythoMax 13B for Story generation.

How much does Llama 3.1 405B cost vs MythoMax 13B?

Llama 3.1 405B: $0.08/1M input, $0.14/1M output. MythoMax 13B: $0.01/1M input, $0.02/1M 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 MythoMax 13B 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.