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GPT-5 vs Llama 3.1 405B

Compare OpenAI and Meta (via Together AI) AI models

OpenAI
GPT-5
vs
Meta (via Together AI)
Llama 3.1 405B

Cost Comparison (1000 input + 500 output tokens, 100 requests/day)

GPT-5

Per Request:$0.006250
Daily:$0.625
Monthly:$18.75
Yearly:$228.125

Llama 3.1 405B

Per Request:$0.005250
Daily:$0.525
Monthly:$15.75
Yearly:$191.625

Cost Differences

$0.001000
Per Request
$0.10
Daily
$3.00
Monthly
$36.50
Yearly

Llama 3.1 405B costs less than GPT-5

Feature Comparison

FeatureGPT-5Llama 3.1 405B
ProviderOpenAIMeta (via Together AI)
Input Price$1.25/1M tokens$3.50/1M tokens
Output Price$10.00/1M tokens$3.50/1M tokens
Context Window1,000,000 tokens128,000 tokens
Max Output131,072 tokens32,768 tokens
Categoryflagshipflagship
Capabilities
textvisionaudiocode
textcodereasoning
Release Date8/7/20257/23/2024

GPT-5 vs Llama 3.1 405B: Which Should You Choose?

Choosing between GPT-5 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 offers a significantly larger context window at 1,000,000 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.

Both models are in the flagship category, making this a direct head-to-head comparison. At scale — say 10,000 requests per day — the cost difference adds up: Llama 3.1 405B would save you roughly $300.00/month compared to GPT-5. For startups and indie developers, that difference can be significant.

Output costs matter too. GPT-5 charges $10.00/1M 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.

Multimodal capabilities: GPT-5 supports vision (image inputs) while Llama 3.1 405B is text-only. If your application needs image understanding, this narrows your choice.

Best Use Cases

Choose GPT-5 when:

  • • Budget is a primary concern
  • • You need a larger context window (1,000,000 tokens)
  • • You need more capabilities (vision, audio)
  • • You need longer outputs (up to 131,072 tokens)
  • • You're already using OpenAI's API ecosystem

Choose Llama 3.1 405B when:

  • • You're already using Meta (via Together AI)'s API ecosystem

Try Different Scenarios

Use the calculator below to see how costs change with different usage patterns

GPT-5 (OpenAI)

Llama 3.1 405B (Meta (via Together AI))

Start using GPT-5 today

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Start using Llama 3.1 405B today

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Frequently Asked Questions

Which is cheaper, GPT-5 or Llama 3.1 405B?
Llama 3.1 405B is cheaper for input tokens at $3.50 per million tokens vs $1.25 for GPT-5.
What is the context window difference between GPT-5 and Llama 3.1 405B?
GPT-5 supports 1,000,000 tokens while Llama 3.1 405B supports 128,000 tokens — a difference of 872,000 tokens in favor of GPT-5.
Which model is better for AI Chatbot?
Both models support text. For ai chatbot, Llama 3.1 405B is the lower-cost option, while GPT-5 offers a larger context window (1,000,000 vs 128,000 tokens). Choose Llama 3.1 405B for budget sensitivity or GPT-5 for longer context tasks.
Which model has better overall pricing for heavy usage?
At 100 requests/day with 1,000 input and 500 output tokens each, GPT-5 costs about $18.75/month and Llama 3.1 405B costs about $15.75/month. Overall, Llama 3.1 405B has lower combined input + output rates ($3.50 in, $3.50 out) vs GPT-5.

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