Grok 4 Fast Reasoning
Provider: xai ·
xai/grok-4-fast-reasoning Pricing per million tokens
| Component | USD per 1M tokens |
|---|---|
| Input | $0.20 |
| Output | $0.50 |
| Cached input (read) | $0.05 |
💡 With prompt caching, you save up to 75% on cached input tokens — massive for repeated context like system prompts, RAG retrieval, or long conversations.
Monthly cost estimates
Assuming 30% prompt-cache hit rate where available. Adjust for your actual usage.
Small
1M in / 200k out
$0.26
per month
Saves $0.04 via caching
Medium
10M in / 2000k out
$2.55
per month
Saves $0.45 via caching
Large
100M in / 20000k out
$25.50
per month
Saves $4.50 via caching
Context
- Input window
- 2,000,000 tokens
- Max output
- 2,000,000 tokens
Capabilities
- ⬜ Vision (image input)
- ✅ Function / tool calling
- ✅ Prompt caching
- ✅ Web search
- ⬜ JSON / response schema
Compare Grok 4 Fast Reasoning with similar models
Grok 4 Fast Non Reasoning
xai
$0.20 in
/ $0.50 out
Grok 4 1 Fast
xai
$0.20 in
/ $0.50 out
Grok 4 1 Fast Reasoning
xai
$0.20 in
/ $0.50 out
Grok 4 1 Fast Reasoning Latest
xai
$0.20 in
/ $0.50 out
Grok 4 1 Fast Non Reasoning
xai
$0.20 in
/ $0.50 out
Grok 4 1 Fast Non Reasoning Latest
xai
$0.20 in
/ $0.50 out
Pricing data sourced from LiteLLM and refreshed regularly. Last updated May 20, 2026. Always verify with the provider's official pricing page before making business decisions.