GPT-5 Nano vs Grok 3: Detailed Comparison
Choosing between GPT-5 Nano (OpenAI) and
Grok 3 (xAI) comes down to three things:
per-token pricing, context window, and which capability matters most for your workload.
GPT-5 Nano costs $0.05/M input vs
$3.00/M for Grok 3;
context windows are 400K vs
1.0M tokens. Detailed breakdown below.
Side-by-side specs
| Spec | GPT-5 Nano | Grok 3 |
|---|
| Provider | OpenAI | xAI |
|---|
| Released | 2025-08-07 | 2025-02-17 |
|---|
| Input price |
$0.05/M |
$3.00/M |
| Output price |
$0.40/M |
$15.00/M |
| Cached input |
$0.0050/M |
— |
| Context window |
400K |
1.0M |
| Max output |
64K |
16K |
| Modalities |
text |
text image |
| Tokenizer |
o200k_base |
grok |
Capability matrix
| Capability | GPT-5 Nano | Grok 3 |
|---|
| function calling |
Yes |
Yes |
| json mode |
Yes |
Yes |
| streaming |
Yes |
Yes |
| vision |
No |
Yes |
| realtime web |
No |
Yes |
Benchmark comparison
Higher is better for all benchmarks shown.
Per-call cost on typical workloads
| Workload (in/out tokens) | GPT-5 Nano | Grok 3 | Cheaper by |
|---|
| Standard chat (1K / 500) |
$0.000250 |
$0.010500 |
GPT-5 Nano by $0.010250 |
| RAG (4K / 500) |
$0.000400 |
$0.019500 |
GPT-5 Nano by $0.019100 |
| Long doc (20K / 1K) |
$0.001400 |
$0.075000 |
GPT-5 Nano by $0.073600 |
| Very long context (100K / 2K) |
$0.005600 |
$0.322500 |
GPT-5 Nano by $0.316900 |
When to choose GPT-5 Nano over Grok 3
- Per-token input cost is 98% lower — meaningful for high-volume workloads.
When to choose Grok 3 over GPT-5 Nano
- Larger context window (1.0M vs 400K).
- Supports vision — GPT-5 Nano does not.
- Supports realtime web — GPT-5 Nano does not.
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