Gemini 3.1 Flash-Lite vs Grok 4.3
Gemini 3.1 Flash-Lite (2026) and Grok 4.3 (2026) are frontier reasoning models from Google DeepMind and xAI. Gemini 3.1 Flash-Lite ships a 1M-token context window, while Grok 4.3 ships a 1M-token context window. On pricing, Gemini 3.1 Flash-Lite costs $0.25/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.
Gemini 3.1 Flash-Lite is ~400% cheaper at $0.25/1M; pay for Grok 4.3 only for reasoning depth.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-05-07 | 2026-04-30 |
| Context window | 1M | 1M |
| Parameters | — | ~0.5T |
| Architecture | decoder only | - |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-01 | - |
Pricing and availability
| Pricing attribute | Gemini 3.1 Flash-Lite | Grok 4.3 |
|---|---|---|
| Input price | $0.25/1M tokens | $1.25/1M tokens |
| Output price | $1.5/1M tokens | $2.5/1M tokens |
| Providers |
Capabilities
| Capability | Gemini 3.1 Flash-Lite | Grok 4.3 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on reasoning mode: Grok 4.3 and code execution: Gemini 3.1 Flash-Lite. Both models share vision, multimodal input, function calling, and tool use, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Gemini 3.1 Flash-Lite lists $0.25/1M input and $1.5/1M output tokens, while Grok 4.3 lists $1.25/1M input and $2.5/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Gemini 3.1 Flash-Lite lower by about $1 per million blended tokens. Availability is 2 providers versus 2, so concentration risk also matters.
Choose Gemini 3.1 Flash-Lite when coding workflow support, larger context windows, and lower input-token cost are central to the workload. Choose Grok 4.3 when reasoning depth are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, Gemini 3.1 Flash-Lite or Grok 4.3?
Gemini 3.1 Flash-Lite supports 1M tokens, while Grok 4.3 supports 1M tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Gemini 3.1 Flash-Lite or Grok 4.3?
Gemini 3.1 Flash-Lite is cheaper on tracked token pricing. Gemini 3.1 Flash-Lite costs $0.25/1M input and $1.5/1M output tokens. Grok 4.3 costs $1.25/1M input and $2.5/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Gemini 3.1 Flash-Lite or Grok 4.3 open source?
Gemini 3.1 Flash-Lite is listed under Proprietary. Grok 4.3 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Gemini 3.1 Flash-Lite or Grok 4.3?
Both Gemini 3.1 Flash-Lite and Grok 4.3 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, Gemini 3.1 Flash-Lite or Grok 4.3?
Both Gemini 3.1 Flash-Lite and Grok 4.3 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Gemini 3.1 Flash-Lite and Grok 4.3?
Gemini 3.1 Flash-Lite is available on Google AI Studio and OpenRouter. Grok 4.3 is available on xAI Console and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-11. Data sourced from public model cards and provider documentation.