Grok 3 vs Llama 3.1 405B: Detailed Comparison
Choosing between Grok 3 (xAI) and
Llama 3.1 405B (Meta) comes down to three things:
per-token pricing, context window, and which capability matters most for your workload.
Grok 3 costs $3.00/M input vs
$3.50/M for Llama 3.1 405B;
context windows are 1.0M vs
128K tokens. Detailed breakdown below.
Side-by-side specs
| Spec | Grok 3 | Llama 3.1 405B |
|---|
| Provider | xAI | Meta |
|---|
| Released | 2025-02-17 | 2024-07-23 |
|---|
| Input price |
$3.00/M |
$3.50/M |
| Output price |
$15.00/M |
$3.50/M |
| Cached input |
— |
— |
| Context window |
1.0M |
128K |
| Max output |
16K |
4K |
| Modalities |
text image |
text |
| Tokenizer |
grok |
llama-3 |
Capability matrix
| Capability | Grok 3 | Llama 3.1 405B |
|---|
| function calling |
Yes |
Yes |
| json mode |
Yes |
Yes |
| vision |
Yes |
No |
| streaming |
Yes |
Yes |
| realtime web |
Yes |
No |
Benchmark comparison
Higher is better for all benchmarks shown.
Per-call cost on typical workloads
| Workload (in/out tokens) | Grok 3 | Llama 3.1 405B | Cheaper by |
|---|
| Standard chat (1K / 500) |
$0.010500 |
$0.005250 |
Llama 3.1 405B by $0.005250 |
| RAG (4K / 500) |
$0.019500 |
$0.015750 |
Llama 3.1 405B by $0.003750 |
| Long doc (20K / 1K) |
$0.075000 |
$0.073500 |
Llama 3.1 405B by $0.001500 |
| Very long context (100K / 2K) |
$0.322500 |
$0.355250 |
Grok 3 by $0.032750 |
When to choose Grok 3 over Llama 3.1 405B
- Per-token input cost is 14% lower — meaningful for high-volume workloads.
- Larger context window (1.0M vs 128K) — relevant when whole documents or long histories must fit in a single call.
- Supports vision — Llama 3.1 405B does not.
- Supports realtime web — Llama 3.1 405B does not.
When to choose Llama 3.1 405B over Grok 3
- Llama 3.1 405B fits when your stack is already on Meta.
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