AllocateMeta Llama 3.1 405B Instruct vs Grok 4.5
On provider list prices, Meta Llama 3.1 405B Instruct costs $3.50 per million input tokens against $2 for Grok 4.5: effectively level. Output is $3.50 against $6 (1.7x).
Meta Llama 3.1 405B Instruct
Grok 4.5Specifications and provider list prices from the Allocate catalog, checked 2026-07-21.
What the numbers say
Take 1,000,000 requests a month at 1,200 input and 350 output tokens each. That workload costs $4,500 a month on Grok 4.5 and $5,425 on Meta Llama 3.1 405B Instruct at list: a gap of $925, or 1.2x.
Grok 4.5 reads 500K tokens per request against 4K for Meta Llama 3.1 405B Instruct, 122.1x the window. That decides which one can take whole documents without splitting them.
Choose Meta Llama 3.1 405B Instruct for
- Open weights you can fine-tune and own
Choose Grok 4.5 for
- The lower list price ($2 in / $6 out per M tokens)
- The longer context window (500K vs 4K tokens)
- Published cached-input pricing ($0.30 per M tokens)
Common questions
Which is cheaper, Meta Llama 3.1 405B Instruct or Grok 4.5?
Grok 4.5, on this workload shape. At list prices it is $2/$6 per million tokens in and out against $3.50/$3.50 for Meta Llama 3.1 405B Instruct. Billed on Allocate: $2.14/$6.42 against $3.75/$3.75.
Which has the bigger context window?
Grok 4.5: 500,000 tokens (500K) against 4,096 (4K) for Meta Llama 3.1 405B Instruct.
Can I fine-tune Meta Llama 3.1 405B Instruct or Grok 4.5?
Meta Llama 3.1 405B Instruct publishes open weights (Llama community) and can be fine-tuned on your own data. Grok 4.5 is a closed model served over API; its weights are not available.
Related comparisons
Run the numbers on your workload
Or don’t choose. On Allocate a route name is the contract: point yours at one model today, swap to the other tomorrow, and compare them on your live traffic with per-token metering.