Comparison

Llama 4 vs GPT-5: Open vs Closed

Comparing Meta's open-weight Llama 4 with OpenAI's GPT-5 for production.

· 5 min read

Meta's Llama 4 (April 2025) brought open-weight models to near-frontier performance. GPT-5 (August 2025) remains the closed-source leader. The choice depends on your control, cost, and capability requirements.

Llama 4 Overview

Llama 4 introduced mixture-of-experts and native multimodality:

  • Models: Llama 4 Scout, Llama 4 Maverick, Llama 4 Behemoth
  • Architecture: Mixture of Experts (MoE), FP8 training
  • Multimodal: Native text, image, video, audio
  • License: Open-weight (Llama 4 Community License)

GPT-5 Overview

  • Context: 400K tokens
  • Variants: gpt-5, gpt-5-mini, gpt-5-nano
  • Architecture: Unified routing system
  • License: Proprietary API access only

When to Choose Llama 4

  • Data sovereignty: Self-host for full control
  • Cost at scale: No per-token API fees
  • Customization: Fine-tune for your domain
  • Compliance: Keep data on-premises

When to Choose GPT-5

  • Peak capability: Still leads on complex reasoning
  • No infrastructure: API-only, no GPUs to manage
  • Ecosystem: Broadest third-party integrations
  • Rapid iteration: Continuous model updates

Safety Monitoring for Both

Self-hosted or API—both need observability:

  • Llama 4 self-hosted still needs hallucination detection
  • GPT-5 API outputs still need policy monitoring
  • Both can leak PII from context
  • Track metrics to compare actual performance

Is Llama 4 as good as GPT-5?

Llama 4 Maverick and Behemoth approach GPT-5 on many benchmarks. For many production use cases, Llama 4 is sufficient. GPT-5 still leads on complex multi-step reasoning. Test both for your specific workload.

Do I need monitoring for self-hosted Llama?

Yes. Self-hosting doesn't eliminate hallucinations, policy violations, or PII leakage. You still need observability to track safety metrics and catch issues before users do.

Monitor any LLM—API or self-hosted

Track hallucinations and safety metrics for Llama, GPT-5, or any provider.

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