LLM Reference

Llama 3 8B Instruct vs Phi 3.5 Mini Instruct

Llama 3 8B Instruct (2024) and Phi 3.5 Mini Instruct (2024) are compact production models from AI at Meta and Microsoft Research. Llama 3 8B Instruct ships a 8k-token context window, while Phi 3.5 Mini Instruct ships a 128k-token context window. On pricing, Llama 3 8B Instruct costs $0.02/1M input tokens versus $0.90/1M 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.

Llama 3 8B Instruct is ~4400% cheaper at $0.02/1M; pay for Phi 3.5 Mini Instruct only for long-context analysis.

Decision scorecard

Local evidence first
SignalLlama 3 8B InstructPhi 3.5 Mini Instruct
Best forprovider-routed productionprovider-routed production
Decision fitCoding, Classification, and JSON / Tool useLong context
Context window8k128k
Cheapest output$0.05/1M tokens$0.90/1M tokens
Provider routes17 tracked2 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose Llama 3 8B Instruct when...
  • Llama 3 8B Instruct has the lower cheapest tracked output price at $0.05/1M tokens.
  • Llama 3 8B Instruct has broader tracked provider coverage for fallback and route flexibility.
  • Llama 3 8B Instruct uniquely exposes Structured outputs in local model data.
  • Local decision data tags Llama 3 8B Instruct for Coding, Classification, and JSON / Tool use.
Choose Phi 3.5 Mini Instruct when...
  • Phi 3.5 Mini Instruct has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Local decision data tags Phi 3.5 Mini Instruct for Long context.

Monthly cost at traffic

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

Lower estimate Llama 3 8B Instruct

Llama 3 8B Instruct

$28.50

Cheapest tracked route/tier: DeepInfra

Phi 3.5 Mini Instruct

$945

Cheapest tracked route/tier: Fireworks AI

Estimated monthly gap: $917. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Llama 3 8B Instruct -> Phi 3.5 Mini Instruct
  • Provider overlap exists on Fireworks AI and NVIDIA NIM; start route-level A/B tests there.
  • Phi 3.5 Mini Instruct is $0.85/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Check replacement coverage for Structured outputs before moving production traffic.
Phi 3.5 Mini Instruct -> Llama 3 8B Instruct
  • Provider overlap exists on Fireworks AI and NVIDIA NIM; start route-level A/B tests there.
  • Llama 3 8B Instruct is $0.85/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Llama 3 8B Instruct adds Structured outputs in local capability data.

Specs

Specification
Released2024-04-182024-08-20
Context window8k128k
Parameters8B3.8B
ArchitectureDecoder OnlyDecoder Only
LicenseLlama 3 CommunityMITOSI-approved
OpennessOpen weightsOpen source
WeightsAvailableUnknown
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff2023-032023-10

Pricing and availability

Pricing attributeLlama 3 8B InstructPhi 3.5 Mini Instruct
Input price$0.02/1M tokens$0.90/1M tokens
Output price$0.05/1M tokens$0.90/1M tokens
Providers

Capabilities

CapabilityLlama 3 8B InstructPhi 3.5 Mini Instruct
VisionNoNo
MultimodalNoNo
ReasoningNoNo
JSON / Tool useNoNo
Structured outputsYesNo
Code executionNoNo
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.