Side by side pricing and context for Grok 4 Fast and GPT-5 Mini. Rates are curated catalog values with last verified dates on each model page.
Grok 4 Fast
Faster, cheaper Grok 4 tier for volume chat on xAI. Prefer when latency and cost beat peak Grok 4 quality for your workload.
Input $0.200 / Output $0.500 per 1M
Context 256K · Approx
GPT-5 Mini
Lower-cost GPT-5 tier for high-volume chat and light reasoning. Good default when GPT-5 is overkill but you still want the GPT-5 family tokenizer (Exact in TokenCALC).
Input $0.250 / Output $2.00 per 1M
Context 128K · Exact (o200k_base)
Quick take
- Grok 4 Fast is cheaper on input in this catalog snapshot.
- Grok 4 Fast is cheaper on output in this catalog snapshot.
- Both last verified on their model pages (2026-08-02 / 2026-08-02).
Rate table
| Metric | Grok 4 Fast | GPT-5 Mini |
|---|---|---|
| Input / 1M | $0.200 | $0.250 |
| Output / 1M | $0.500 | $2.00 |
| Cached input / 1M | n/a | $0.025 |
| Context | 256K | 128K |
| Tokenizer | Approx | Exact (o200k_base) |