GPT-5.3 Codex vs Llama 3.1 405B
GPT-5.3 Codex vs Llama 3.1 405B: GPT-5.3 Codex is cheaper for input-heavy usage ($1.75/M vs $3.50/M input tokens), while GPT-5.3 Codex is better for long-context tasks (256,000 tokens).
Direct answer: choose GPT-5.3 Codex for lower token spend and choose GPT-5.3 Codex when your workload needs longer context.
Compare input and output token pricing, context windows, and monthly cost estimates on one page so you can pick the cheaper model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.3 Codex
Llama 3.1 405B
Cost Differences
Llama 3.1 405B costs less than GPT-5.3 Codex
Quick Recommendation
Winner for direct API pricing: Llama 3.1 405B. At the default workload, Llama 3.1 405B saves about $10.50/month ($127.75/year) versus GPT-5.3 Codex.
Feature Comparison
| Feature | GPT-5.3 Codex | Llama 3.1 405B |
|---|---|---|
| Provider | OpenAI | Meta (via Together AI) |
| Input Price | $1.75/1M tokens | $3.50/1M tokens |
| Output Price | $14.00/1M tokens | $3.50/1M tokens |
| Context Window | 256,000 tokens | 128,000 tokens |
| Max Output | 32,768 tokens | 32,768 tokens |
| Category | coding | flagship |
| Capabilities | textcode | textcodereasoning |
| Release Date | 3/1/2026 | 7/23/2024 |
GPT-5.3 Codex vs Llama 3.1 405B: Which Should You Choose?
Choosing between GPT-5.3 Codex and Llama 3.1 405B depends on your priorities: cost efficiency, context length, or raw capability. Llama 3.1 405B is the more affordable option at $3.50/1M input tokens. Meanwhile, GPT-5.3 Codex offers a significantly larger context window at 256,000 tokens vs 128,000 for Llama 3.1 405B.
These models come from different providers — OpenAI and Meta (via Together AI) — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to Meta (via Together AI)involves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: GPT-5.3 Codex is a coding model while Llama 3.1 405B is flagship. This means they're optimized for different workloads. Llama 3.1 405B targets more demanding workloads, while GPT-5.3 Codex provides a cost-effective option for everyday tasks.
Output costs matter too. GPT-5.3 Codex charges $14.00/1M output tokens vs $3.50 for Llama 3.1 405B. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Llama 3.1 405B has the edge here at $3.50/1M output tokens.
Best Use Cases
Choose GPT-5.3 Codex when:
- • Budget is a primary concern
- • You need a larger context window (256,000 tokens)
- • You're already using OpenAI's API ecosystem
Choose Llama 3.1 405B when:
- • You need more capabilities (reasoning)
- • You're already using Meta (via Together AI)'s API ecosystem
Pros and Caveats at a Glance
GPT-5.3 Codex
- • Input pricing: $1.75/M tokens
- • Output pricing: $14.00/M tokens
- • Context window: 256,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Higher output cost than Llama 3.1 405B
Llama 3.1 405B
- • Input pricing: $3.50/M tokens
- • Output pricing: $3.50/M tokens
- • Context window: 128,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Higher input cost than GPT-5.3 Codex
- • Smaller context window than GPT-5.3 Codex
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.3 Codex (OpenAI)
Llama 3.1 405B (Meta (via Together AI))
Start using GPT-5.3 Codex today
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Sign Up for Meta (via Together AI) →Frequently Asked Questions
Which is cheaper, GPT-5.3 Codex or Llama 3.1 405B?▼
What is the context window difference between GPT-5.3 Codex and Llama 3.1 405B?▼
Which model is better for AI Chatbot?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare OpenAI and Meta (via Together AI) API pricing beyond this model matchup?▼
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