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TokenMath.net
Updated 2026-09-22 11:16 UTC
Head-to-Head Specification Battle

Llama 3.1 405B — Together AI vs Llama 4 Vivas

Side-by-side technical and economic comparison between Meta / Together's Llama 3.1 405B — Together AI and Meta / Together's Llama 4 Vivas.

Endpoint Availability & Transition Notice

Llama 3.1 405B — Together AI: Classified as a Legacy Reference model (Deprecated on Together AI (Reference)).

Core Technical & Pricing Comparison
MetricLlama 3.1 405B — Together AILlama 4 VivasAdvantage
Provider OrganizationMeta / TogetherMeta / Together
Standard Input / 1M$3.50$0.25Llama 4 Vivas (93% lower)
Cached Input / 1MNone$0.06Llama 4 Vivas lower
Output / 1M$3.50$0.85Llama 4 Vivas lower
Context Window128k1MLlama 4 Vivas (1M)
Max Generation Tokens4.1k128kLlama 4 Vivas
Tokenizer FamilyMeta Llama 3 Tiktoken BPE (~128k vocabulary)Meta Llama 3 Tokenizer (128k vocabulary)

Interactive Side-by-Side Cost Simulator

Live Delta
Input Tokens / Req2,500
Output Tokens / Req800
Daily Requests10,000
Llama 3.1 405B — Together AI
$3,465.00 / month
$0.0116 / request
Llama 4 VivasLOWER COST
$320.25 / month
$0.00107 / request
Selecting Llama 4 Vivas saves $3,144.75 / month (90.8% savings) over Llama 3.1 405B — Together AI.

When to Choose Llama 3.1 405B — Together AI

Opt for Llama 3.1 405B — Together AI when your engineering requirements prioritize Meta / Together's ecosystem, specific tokenizer efficiencies (Exact Llama 3 Tokenizer (±2%)), or when your expected prompt-to-completion ratios favor its $3.5/M input rate.

When to Choose Llama 4 Vivas

Opt for Llama 4 Vivas when looking for Meta / Together's tooling integration, specific context window depth (1M tokens), or when output generation volume favors its $0.85/M rate.