Llama 3.1 405B vs Runway Gen-3 Alpha

Compare Llama 3.1 405B and Runway Gen-3 Alpha: 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 Runway models What is an LLM API? Python Quickstart What is inference?
Feature Llama 3.1 405B Runway Gen-3 Alpha
CategoryOpen SourceVideo
Parameters405B~8B
Context Window128KN/A
Input Price$0.08/1M tokens$0.25/video/1M tokens
Output Price$0.14/1M tokensN/A/1M tokens
Latency~600ms~45s

Choose Llama 3.1 405B when:

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

Largest open model, Highest open-source quality

Choose Runway Gen-3 Alpha when:

  • ✓ Film production
  • ✓ Advertising
  • ✓ Content creation
Key Strengths:

Cinematic quality, Good control, Professional

Verdict: Llama 3.1 405B vs Runway Gen-3 Alpha

For cost efficiency, Llama 3.1 405B wins at $0.08/1M input tokens. For speed, Runway Gen-3 Alpha is faster at ~45s. Llama 3.1 405B excels at Premium tasks while Runway Gen-3 Alpha is better for Film production. 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. Runway Gen-3 Alpha costs $0.25/video input and N/A output. Llama 3.1 405B is 3.1x 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. Runway Gen-3 Alpha offers N/A context at ~45s. 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. Runway Gen-3 Alpha (Video) works best for: Film production, Advertising, Content creation.

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 Runway Gen-3 Alpha
response_b = client.chat.completions.create(
    model="runway-gen3-alpha",
    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 Runway Gen-3 Alpha?

Llama 3.1 405B (Open Source, 405B) offers Largest open model. Runway Gen-3 Alpha (Video, ~8B) offers Cinematic quality. Choose Llama 3.1 405B for Premium tasks or Runway Gen-3 Alpha for Film production.

How much does Llama 3.1 405B cost vs Runway Gen-3 Alpha?

Llama 3.1 405B: $0.08/1M input, $0.14/1M output. Runway Gen-3 Alpha: $0.25/video/1M input, N/A/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 Runway Gen-3 Alpha 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.