LLM Reference

GPT-5.4 vs Llama 3.1 405B Instruct

GPT-5.4 (2026) and Llama 3.1 405B Instruct (2024) are frontier reasoning models from OpenAI and AI at Meta. GPT-5.4 ships a 1.05m-token context window, while Llama 3.1 405B Instruct ships a 128k-token context window. On pricing, GPT-5.4 ranges from $2.50 to $5/1M input tokens by tier; Llama 3.1 405B Instruct costs $2.40/1M input tokens. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

GPT-5.4 fits 8x more tokens; pick it for long-context work and Llama 3.1 405B Instruct for tighter calls.

Decision scorecard

Local evidence first
SignalGPT-5.4Llama 3.1 405B Instruct
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsprovider-routed production
Decision fitCoding, RAG, and AgentsRAG, Long context, and Classification
Context window1.05m128k
Cheapest output$15/1M tokens$2.40/1M tokens
Provider routes4 tracked11 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose GPT-5.4 when...
  • GPT-5.4 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • GPT-5.4 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
  • Local decision data tags GPT-5.4 for Coding, RAG, and Agents.
Choose Llama 3.1 405B Instruct when...
  • Llama 3.1 405B Instruct has the lower cheapest tracked output price at $2.40/1M tokens.
  • Llama 3.1 405B Instruct has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags Llama 3.1 405B Instruct for RAG, Long context, and Classification.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Lower estimate Llama 3.1 405B Instruct

GPT-5.4

$5,750

Cheapest tracked route/tier: OpenAI API

Llama 3.1 405B Instruct

$2,520

Cheapest tracked route/tier: AWS Bedrock

Estimated monthly gap: $3,230. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

GPT-5.4 -> Llama 3.1 405B Instruct
  • Provider overlap exists on AWS Bedrock; start route-level A/B tests there.
  • Llama 3.1 405B Instruct is $12.60/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
Llama 3.1 405B Instruct -> GPT-5.4
  • Provider overlap exists on AWS Bedrock; start route-level A/B tests there.
  • GPT-5.4 is $12.60/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • GPT-5.4 adds Vision, Multimodal, and Reasoning in local capability data.

Specs

Specification
Released2026-03-052024-07-23
Context window1.05m128k
Parameters405B
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryLlama 3 Community
OpennessProprietaryOpen weights
WeightsNot releasedAvailable
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-082023-12

Pricing and availability

Pricing attributeGPT-5.4Llama 3.1 405B Instruct
Input price
0-272,000t
$2.50/1M tokens
272,000t+
$5/1M tokens
$2.40/1M tokens
Output price
0-272,000t
$15/1M tokens
272,000t+
$22.50/1M tokens
$2.40/1M tokens
Providers

Capabilities

CapabilityGPT-5.4Llama 3.1 405B Instruct
VisionYesNo
MultimodalYesNo
ReasoningYesNo
JSON / Tool useYesNo
Structured outputsYesYes
Code executionYesNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark scores are currently available for this pair.

Continue comparing

Last reviewed: 2026-07-11. Data sourced from public model cards and provider documentation.