LLM Reference

Gemini 2.5 Flash vs Llama 3.1 405B Instruct

Gemini 2.5 Flash (2025) and Llama 3.1 405B Instruct (2024) are compact production models from Google DeepMind and AI at Meta. Gemini 2.5 Flash ships a 1m-token context window, while Llama 3.1 405B Instruct ships a 128k-token context window. On pricing, Gemini 2.5 Flash costs $0.30/1M input tokens versus $2.40/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

Gemini 2.5 Flash is ~700% cheaper at $0.30/1M; pay for Llama 3.1 405B Instruct only for provider fit.

Decision scorecard

Local evidence first
SignalGemini 2.5 FlashLlama 3.1 405B Instruct
Best formultimodal apps, tool-calling agents, and long-context analysisprovider-routed production
Decision fitCoding, RAG, and AgentsRAG, Long context, and Classification
Context window1m128k
Cheapest output$2.50/1M tokens$2.40/1M tokens
Provider routes6 tracked11 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose Gemini 2.5 Flash when...
  • Gemini 2.5 Flash has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Gemini 2.5 Flash uniquely exposes Vision, Multimodal, and JSON / Tool use in local model data.
  • Local decision data tags Gemini 2.5 Flash 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 Gemini 2.5 Flash

Gemini 2.5 Flash

$865

Cheapest tracked route/tier: Google AI Studio

Llama 3.1 405B Instruct

$2,520

Cheapest tracked route/tier: AWS Bedrock

Estimated monthly gap: $1,655. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Gemini 2.5 Flash -> Llama 3.1 405B Instruct
  • Provider overlap exists on GCP Vertex AI; start route-level A/B tests there.
  • Llama 3.1 405B Instruct is $0.10/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and JSON / Tool use before moving production traffic.
Llama 3.1 405B Instruct -> Gemini 2.5 Flash
  • Provider overlap exists on GCP Vertex AI; start route-level A/B tests there.
  • Gemini 2.5 Flash is $0.10/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Gemini 2.5 Flash adds Vision, Multimodal, and JSON / Tool use in local capability data.

Specs

Specification
Released2025-06-172024-07-23
Context window1m128k
Parameters405B
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryLlama 3 Community
OpennessProprietaryOpen weights
WeightsNot releasedAvailable
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-012023-12

Pricing and availability

Pricing attributeGemini 2.5 FlashLlama 3.1 405B Instruct
Input price$0.30/1M tokens$2.40/1M tokens
Output price$2.50/1M tokens$2.40/1M tokens
Providers

Capabilities

CapabilityGemini 2.5 FlashLlama 3.1 405B Instruct
VisionYesNo
MultimodalYesNo
ReasoningNoNo
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.