Gemini 3.1 Flash Lite vs Grok 4.3

Google · US  |  xAI · US · Updated June 2026

Quick verdict

Pick Gemini 3.1 Flash Lite for ultra-low-latency, high-volume production workloads or most cost-efficient gemini 3 model — half the price of gemini 3 flash ($0.25/$1.50 vs $0.50/$3.00 per 1m tokens). Pick Grok 4.3 for video understanding from native video input or generating pdf, pptx, and xlsx files directly. On a tight budget at scale, Gemini 3.1 Flash Lite is the value pick.

Gemini 3.1 Flash Lite (Google) and Grok 4.3 (xAI) are two of the models people most often weigh against each other in 2026. Gemini 3.1 Flash Lite is google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash. Grok 4.3 is the current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. Their biggest split is price, and the breakdown below shows exactly how that plays out for your workload.

Key differences at a glance

Side-by-side specs

SpecGemini 3.1 Flash LiteGrok 4.3
ProviderGoogle (US) xAI (US)
ReleasedMarch 3, 2026 April 30, 2026
Context window1M (~1,500 pages) 1M (~1,500 pages)
Price (in/out)$0.25/$1.5 per 1M tokens $1.25/$2.5 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, audio, video text, image, video, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1M12.3% Not published

Who wins what

Ultra-low-latency, high-volume production workloads

Gemini 3.1 Flash Lite

A core design strength of Gemini 3.1 Flash Lite.

Most cost-efficient Gemini 3 model — half the price of Gemini 3 Flash ($0.25/$1.50 vs $0.50/$3.00 per 1M tokens)

Gemini 3.1 Flash Lite

A core design strength of Gemini 3.1 Flash Lite.

High-volume agentic and tool-calling loops where cost per call matters

Gemini 3.1 Flash Lite

A core design strength of Gemini 3.1 Flash Lite.

Video understanding from native video input

Grok 4.3

A core design strength of Grok 4.3.

Generating PDF, PPTX, and XLSX files directly

Grok 4.3

A core design strength of Grok 4.3.

Real-time questions using live X data

Grok 4.3

A core design strength of Grok 4.3.

Lowest cost at scale

Gemini 3.1 Flash Lite

At $0.25/$1.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Which should you pick?

A cost-sensitive startup shipping high volume

Gemini 3.1 Flash Lite

At $0.25/$1.5 per 1M tokens it undercuts Grok 4.3, and on millions of tokens that margin decides the monthly bill.

Anyone whose priority is ultra-low-latency, high-volume production workloads

Gemini 3.1 Flash Lite

It is specifically built for that.

Anyone whose priority is video understanding from native video input

Grok 4.3

That is its strongest area.

Gemini 3.1 Flash Lite: where it fits

Google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash. Released March 3, 2026 by Google, it is built for ultra-low-latency, high-volume production workloads, most cost-efficient Gemini 3 model — half the price of Gemini 3 Flash ($0.25/$1.50 vs $0.50/$3.00 per 1M tokens), high-volume agentic and tool-calling loops where cost per call matters, and multimodal input across text, image, video, audio, and PDF.

Its trade-offs are real: lower reasoning and quality ceiling than Gemini 3.1 Pro and the full Gemini 3 Flash tier, sharp long-context degradation — MRCR v2 (8-needle) retrieval falls to ~12% at the full 1M-token window, and closed weights — not downloadable or self-hostable. At $0.25 in / $1.5 out per million tokens, it sits in the budget price band.

Grok 4.3: where it fits

The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. Released April 30, 2026 by xAI, it is built for video understanding from native video input, generating PDF, PPTX, and XLSX files directly, real-time questions using live X data, and long-context, multi-agent reasoning.

Its trade-offs: higher context pricing on requests above 200K tokens, and less independent benchmark coverage than OpenAI, Anthropic, or Google. At $1.25 in / $2.5 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

Gemini 3.1 Flash Lite and Grok 4.3 overlap enough that the right pick depends on your specific job. Gemini 3.1 Flash Lite costs less per token; and each leads in its own area — Gemini 3.1 Flash Lite for ultra-low-latency, high-volume production workloads, Grok 4.3 for video understanding from native video input. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Gemini 3.1 Flash Lite and Grok 4.3 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is Gemini 3.1 Flash Lite or Grok 4.3 better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Gemini 3.1 Flash Lite leans toward ultra-low-latency, high-volume production workloads while Grok 4.3 leans toward video understanding from native video input, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Gemini 3.1 Flash Lite or Grok 4.3?

Gemini 3.1 Flash Lite is cheaper — $0.25/$1.5 per 1M tokens vs $1.25/$2.5 per 1M tokens, roughly 5× apart on input.

Which has the bigger context window?

Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both Gemini 3.1 Flash Lite and Grok 4.3 together?

Yes — a multi-model platform like LumiChats gives you Gemini 3.1 Flash Lite, Grok 4.3 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, Gemini 3.1 Flash Lite or Grok 4.3?

Grok 4.3 — released April 30, 2026, about 58 days after Gemini 3.1 Flash Lite.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.