Model comparison
Gemini 3.1 Flash-Lite vs Grok 4.20 Reasoning
Compare Gemini 3.1 Flash-Lite vs Grok 4.20 Reasoning API pricing: input/output token costs, cache pricing, context windows, workload estimates, and routing fit.
Gemini 3.1 Flash-Lite
gemini · gemini/gemini-3.1-flash-lite
- Input
- $0.25
- Output
- $1.5
- Context
- 1M
Grok 4.20 Reasoning
xai · grok-4.20-0309-reasoning
- Input
- $1.25
- Output
- $2.5
- Context
- 1M
Quick take
Gemini 3.1 Flash-Lite has the lower input price at $0.25 per 1M input tokens. Gemini 3.1 Flash-Lite is cheaper for the example blended workload below. Gemini 3.1 Flash-Lite has the larger context window at 1M tokens.
Choose Gemini 3.1 Flash-Lite if...
- Gemini 3.1 Flash-Lite is the better default for cost-sensitive traffic and repeated high-volume calls.
- Gemini 3.1 Flash-Lite is safer for long documents, repository analysis, and RAG prompts because it has the larger context window.
- Gemini 3.1 Flash-Lite is required if images, screenshots, or visual documents are part of the workflow.
Choose Grok 4.20 Reasoning if...
- Grok 4.20 Reasoning gives more room for long generated answers, reports, or code output.
Example workload cost
Estimates use input tokens plus 20% output tokens. They exclude provider discounts, cache hits, and tool/search surcharges.
| Workload | Gemini 3.1 Flash-Lite | Grok 4.20 Reasoning | Cheaper |
|---|---|---|---|
| 1M input + 200K output | $0.55 | $1.75 | Gemini 3.1 Flash-Lite |
| 10M input + 2M output | $5.50 | $17.50 | Gemini 3.1 Flash-Lite |
| 100M input + 20M output | $55.00 | $175.00 | Gemini 3.1 Flash-Lite |
Context, output, and capability fit
Gemini 3.1 Flash-Lite provides the larger context window. Check max output separately when the task needs long reports, code generation, or full-document rewrites.
- Gemini 3.1 Flash-Lite max output
- 65.5K
- Grok 4.20 Reasoning max output
- 1M
- Gemini 3.1 Flash-Lite features
- prompt caching, function calling, vision
- Grok 4.20 Reasoning features
- prompt caching, function calling
Risk notes for Gemini 3.1 Flash-Lite
- No major capability risk is flagged in this snapshot, but provider pages should still be verified before production routing.
Risk notes for Grok 4.20 Reasoning
- No major capability risk is flagged in this snapshot, but provider pages should still be verified before production routing.
Routing tags
budgetfasthigh-volumestablemultimodalcache-friendlyragfrontierreasoningagentslong-context