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Comparison · 2 models · Updated Oct 4, 2026

Grok 4.1 Fast vs Gemini 2.5 Flash-Lite

Gemini 2.5 Flash-Lite comes out ahead, 85 to 71 on our weighted score, and it is the cheaper option too.

  1. xAI

    Grok 4.1 Fast

    Released Nov 19, 2025

    71/100
    • ECI—
    • Price$0.20 / $0.50
    • Context2M
  2. Our pick

    Google

    Gemini 2.5 Flash-Lite

    Released Jun 17, 2025

    85/100
    • ECI133.9
    • Price$0.10 / $0.40
    • Context1.05M
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Gemini 2.5 Flash-Lite is our pick

Gemini 2.5 Flash-Lite is the better all-round choice, scoring 85/100 against Grok 4.1 Fast (71). It leads on price and inputs & features. Grok 4.1 Fast wins on context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceGemini 2.5 Flash-LiteGemini 2.5 Flash-Lite $0.175 · Grok 4.1 Fast $0.275 per 1M tokens (3:1 blend)
  • Longest contextGrok 4.1 FastGrok 4.1 Fast 2,000,000 · Gemini 2.5 Flash-Lite 1,048,576 tokens
  • Widest inputsGemini 2.5 Flash-LiteGrok 4.1 Fast: Text, Images · Gemini 2.5 Flash-Lite: Text, Images, PDFs, Audio, Video
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGrok 4.1 FastGemini 2.5 Flash-Lite
Price50%7686
Inputs & features30%60100
Context window20%7261
Overall100%71/10085/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Grok 4.1 Fast vs Gemini 2.5 Flash-Lite specifications side by side
SpecificationGrok 4.1 FastxAIGemini 2.5 Flash-LiteGoogle
Capability
Capabilities Index (ECI)—133.9
ECI rank—#118 of 148
Price per million tokens
Input$0.20$0.10 (best)
Output$0.50$0.40 (best)
Cached input—$0.01
Blended (3:1)$0.275$0.175 (best)
Long-context rateSame rateSame rate
Price sourceMedian of 2 providersOfficial Google API
Limits
Context window2,000,000 tokens (best)1,048,576 tokens
Max output30,000 tokens65,536 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoYes
AudioNoYes
VideoNoYes
ReasoningNoYes
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model ID—gemini-2.5-flash-lite
API providers220 (best)
ReleasedNov 19, 2025Jun 17, 2025
Knowledge cutoff—Jan 2025
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Grok 4.1 Fast$3.00
  • Gemini 2.5 Flash-Lite$1.80
04 — Questions

Which should you choose?

Which is better: Grok 4.1 Fast or Gemini 2.5 Flash-Lite?

Gemini 2.5 Flash-Lite is the better all-round choice, scoring 85/100 against Grok 4.1 Fast (71). It leads on price and inputs & features. Grok 4.1 Fast wins on context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, Grok 4.1 Fast or Gemini 2.5 Flash-Lite?

Gemini 2.5 Flash-Lite is cheaper at $0.10 input / $0.40 output per million tokens (official Google API price). Grok 4.1 Fast costs $0.20 input / $0.50 output per million tokens (median across 2 API providers). At a typical mix of three input tokens to one output token, that is $0.175 per million tokens for Gemini 2.5 Flash-Lite versus $0.275 for Grok 4.1 Fast (1.6× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Grok 4.1 Fast has not been scored yet and Gemini 2.5 Flash-Lite has an ECI of 133.9.

Which is better for coding?

There are no published SWE-bench Verified results for Grok 4.1 Fast and Gemini 2.5 Flash-Lite yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

Grok 4.1 Fast has the largest context window at 2,000,000 tokens, against 1,048,576 for Gemini 2.5 Flash-Lite. Maximum output per response: Grok 4.1 Fast up to 30,000, Gemini 2.5 Flash-Lite up to 65,536 tokens.

Which can read images, PDFs, audio or video?

Grok 4.1 Fast accepts text and images; Gemini 2.5 Flash-Lite accepts text, images, PDFs, audio and video. Gemini 2.5 Flash-Lite handles the widest range of inputs.

Are any of these open source?

No. Grok 4.1 Fast and Gemini 2.5 Flash-Lite are proprietary and only available through APIs and apps.

Which is newer?

Grok 4.1 Fast is the newest, released Nov 19, 2025. Gemini 2.5 Flash-Lite came out Jun 17, 2025. Knowledge cutoff: Gemini 2.5 Flash-Lite Jan 2025.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.