Side-by-side technical and economic comparison between Anthropic's Claude Opus 5 and Meta / Together's Llama 3.1 405B — Together AI.
• Llama 3.1 405B — Together AI: Classified as a Legacy Reference model (Deprecated on Together AI (Reference)).
| Metric | Claude Opus 5 | Llama 3.1 405B — Together AI | Advantage |
|---|---|---|---|
| Provider Organization | Anthropic | Meta / Together | — |
| Standard Input / 1M | $5.00 | $3.50 | Llama 3.1 405B — Together AI (30% lower) |
| Cached Input / 1M | $0.50 | None | Claude Opus 5 lower |
| Output / 1M | $25.00 | $3.50 | Llama 3.1 405B — Together AI lower |
| Context Window | 1M | 128k | Claude Opus 5 (1M) |
| Max Generation Tokens | 16.4k | 4.1k | Claude Opus 5 |
| Tokenizer Family | Anthropic Claude BPE (~65k vocabulary) | Meta Llama 3 Tiktoken BPE (~128k vocabulary) | — |
Opt for Claude Opus 5 when your engineering requirements prioritize Anthropic's ecosystem, specific tokenizer efficiencies (Calibrated Claude Tokenizer (±3%)), or when your expected prompt-to-completion ratios favor its $5/M input rate.
Opt for Llama 3.1 405B — Together AI when looking for Meta / Together's tooling integration, specific context window depth (128k tokens), or when output generation volume favors its $3.5/M rate.