Gemini 3 Flash Preview is $0.75 cheaper per 1M input tokens (60% lower; 2.5x difference).
API cost decision in 10 seconds
🔥Gemini 3 Flash Preview vs Grok 4.20
Pick Gemini 3 Flash Preview for lower cost; pick Grok 4.20 only if the larger context window matters more.
Page updated:
Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick Gemini 3 Flash Preview for lower cost; pick Grok 4.20 only if the larger context window matters more.
On the standard 1M input plus 500K output workload, Gemini 3 Flash Preview is estimated at $2 vs $2.5 for Grok 4.20, saving $0.5 (20% lower).
Cost-first pickGemini 3 Flash Preview
Context-first pickGrok 4.20
Sample savings$0.520%
10x traffic gap$5
Grok 4.20 has more context, but Gemini 3 Flash Preview saves $0.5 on the standard workload. At 10x that traffic, the same price gap is about $5. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Cost winner changes by workload shape: input-heavy / RAG favors Gemini 3 Flash Preview, balanced workload favors Gemini 3 Flash Preview, and output-heavy chatbot favors Grok 4.20.
| Workload shape | Token mix | Better pick | Gemini 3 Flash Preview | Grok 4.20 |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | Gemini 3 Flash Preview | $4 | $7.5 |
| Balanced workload | 1M input + 1M output | Gemini 3 Flash Preview | $3.5 | $3.75 |
| Output-heavy chatbot | 1M input + 5M output | Grok 4.20 | $15.5 | $13.75 |
Grok 4.20 is $0.5 cheaper per 1M output tokens (16.7% lower; 1.2x difference).
Grok 4.20 has 951.42K more context (1.91x larger).
Gemini 3 Flash Preview is $0.5 cheaper on the standard workload (20% lower).
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
Gemini 3 Flash Preview has the lower input price; Grok 4.20 has the lower output price; Grok 4.20 offers the larger context window. For the 1M input plus 500K output sample, Gemini 3 Flash Preview is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $2 for Gemini 3 Flash Preview and $2.5 for Grok 4.20.
Choose Gemini 3 Flash Preview when you care most about lower input-token price.
Choose Grok 4.20 when you care most about lower output-token price, and larger context window.
- On the standard 1M input plus 500K output workload, Gemini 3 Flash Preview is estimated at $2 vs $2.5 for Grok 4.20, saving $0.5 (20% lower).
- Gemini 3 Flash Preview is $0.5 cheaper on the standard workload (20% lower).
- Gemini 3 Flash Preview is $0.75 cheaper per 1M input tokens (60% lower; 2.5x difference).
- Grok 4.20 is $0.5 cheaper per 1M output tokens (16.7% lower; 1.2x difference).
- Grok 4.20 has 951.42K more context (1.91x larger).
| Feature | 🔥Gemini 3 Flash Preview (Google) | Grok 4.20 (xAI) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.5 | $1.25 |
| Completion Price per 1M tokens | $3 | $2.5 |
| Sample Workload Cost 1M input + 500K output | $2 | $2.5 |
| Context Window | 1.05M | 2M |
| Release Date | ||
| Popularity | #7 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | Gemini 3 Flash Preview | On the standard 1M input plus 500K output workload, Gemini 3 Flash Preview is estimated at $2 vs $2.5 for Grok 4.20, saving $0.5 (20% lower). |
| High-volume input processing | Gemini 3 Flash Preview | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | Grok 4.20 | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Grok 4.20 | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- Gemma 4 26B A4B (free) can replace Gemini 3 Flash Preview when lower sample workload cost matters most: $0.
- Gemma 4 31B (free) can replace Gemini 3 Flash Preview when lower sample workload cost matters most: $0.
- Lyria 3 Pro Preview can replace Gemini 3 Flash Preview when lower sample workload cost matters most: $0.
- Lyria 3 Clip Preview can replace Gemini 3 Flash Preview when lower sample workload cost matters most: $0.
- Llama 4 Scout offers 10M context with $0.23 sample workload cost.
- DeepSeek V4 Flash · DeepSeek · #1
- Hy3 preview · Tencent · #2
- Claude Opus 4.7 · Anthropic · #3
- Claude Sonnet 4.6 · Anthropic · #4
Cheaper alternatives
Review low-cost models sorted by a standard 1M input plus 500K output workload.
Open cheapest modelsLarger context alternatives
Find models with larger context windows for RAG, long documents, and codebase review.
Open largest context modelsProvider catalogs
Compare models within provider hubs before choosing a final API vendor.
Open provider hubsGoogle catalog
Review all tracked Google models before deciding whether this matchup is the right shortlist.
Open Google modelsxAI catalog
Check other xAI models with comparable pricing, context, or release timing.
Open xAI modelsGemini 3 Flash Preview is a high speed, high value thinking model designed for agentic workflows, multi turn chat, and coding assistance. It delivers near Pro level reasoning and tool...
Grok 4.20 is a reasoning model from xAI with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict prompt adherance, delivering...