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Comparison · 2 models · Updated Oct 4, 2026

Gemini 2.0 Flash vs Grok 4.20 (Reasoning)

Grok 4.20 (Reasoning) comes out ahead, 78 to 65 on our weighted score, and it is the cheaper option too.

  1. Google

    Gemini 2.0 Flash

    Released Dec 11, 2024

    65/100
    • ECI134.7
    • Price—
    • Context1.05M
    Full specs Remove Gemini 2.0 Flash
  2. Our pick

    xAI

    Grok 4.20 (Reasoning)

    Released Mar 9, 2026

    78/100
    • ECI152.0
    • Price$1.25 / $2.50
    • Context1M
    Full specs Remove Grok 4.20 (Reasoning)

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Grok 4.20 (Reasoning) is our pick

Grok 4.20 (Reasoning) is the better all-round choice, scoring 78/100 against Gemini 2.0 Flash (65). It leads on capability. Gemini 2.0 Flash wins on inputs & features. The score weighs capability 67%, inputs & features 20%, context window 13%.

  • CapabilityGrok 4.20 (Reasoning)Capabilities Index (ECI): Grok 4.20 (Reasoning) 152.0 · Gemini 2.0 Flash 134.7
  • Lowest priceGrok 4.20 (Reasoning)Grok 4.20 (Reasoning) $1.56 per 1M tokens (3:1 blend) · Gemini 2.0 Flash unpriced
  • Longest contextGemini 2.0 FlashGemini 2.0 Flash 1,048,576 · Grok 4.20 (Reasoning) 1,000,000 tokens
  • Widest inputsGemini 2.0 FlashGemini 2.0 Flash: Text, Images, PDFs, Audio, Video · Grok 4.20 (Reasoning): Text, Images, PDFs
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGemini 2.0 FlashGrok 4.20 (Reasoning)
CapabilityCapabilities Index (ECI)67%5981
Inputs & features20%9080
Context window13%6160
Overall100%65/10078/100

Left out because at least one model lacks the data: price. 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.

Gemini 2.0 Flash vs Grok 4.20 (Reasoning) specifications side by side
SpecificationGemini 2.0 FlashGoogleGrok 4.20 (Reasoning)xAI
Capability
Capabilities Index (ECI)134.7152.0 (best)
ECI rank#116 of 148#41 of 148 (best)
GPQA DiamondGraduate-level science questions—89.3%
FrontierMath Tiers 1–3Research-level mathematics—44.9%
OTIS Mock AIME 2024–2025Competition mathematics—92.2%
SimpleQA VerifiedShort factual questions—30.2%
Price per million tokens
Input—$1.25
Output—$2.50
Cached input—$0.20
Blended (3:1)—$1.56
Long-context rate—Over 200K: $2.50 / $5.00
Price source—Official xAI API
Limits
Context window1,048,576 tokens (best)1,000,000 tokens
Max output8,192 tokens30,000 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesYes
AudioYesNo
VideoYesNo
ReasoningNoYes
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model ID—grok-4.20-0309-reasoning
API providers—11
ReleasedDec 11, 2024Mar 9, 2026
Knowledge cutoffJun 2024—
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.

  • Gemini 2.0 Flash—
  • Grok 4.20 (Reasoning)$17.50
04 — Questions

Which should you choose?

Which is better: Gemini 2.0 Flash or Grok 4.20 (Reasoning)?

Grok 4.20 (Reasoning) is the better all-round choice, scoring 78/100 against Gemini 2.0 Flash (65). It leads on capability. Gemini 2.0 Flash wins on inputs & features. The score weighs capability 67%, inputs & features 20%, context window 13%.

Which is cheaper, Gemini 2.0 Flash or Grok 4.20 (Reasoning)?

Grok 4.20 (Reasoning) is cheaper at $1.25 input / $2.50 output per million tokens (official xAI API price). . At a typical mix of three input tokens to one output token, that is $1.56 per million tokens for Grok 4.20 (Reasoning) versus . Gemini 2.0 Flash has no published per-token price.

Which scores higher on benchmarks?

Grok 4.20 (Reasoning) scores higher on the Capabilities Index (ECI): Grok 4.20 (Reasoning) 152.0 (#41 of 148) and Gemini 2.0 Flash 134.7 (#116 of 148). Their confidence ranges do not overlap (149.3–154.4 vs 124.3–136.7), so the gap is a real one.

Which is better for coding?

There are no published SWE-bench Verified results for Gemini 2.0 Flash and Grok 4.20 (Reasoning) yet, so there is no like-for-like coding score. On overall capability, Grok 4.20 (Reasoning) leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

Gemini 2.0 Flash has the largest context window at 1,048,576 tokens, against 1,000,000 for Grok 4.20 (Reasoning). Maximum output per response: Gemini 2.0 Flash up to 8,192, Grok 4.20 (Reasoning) up to 30,000 tokens.

Which can read images, PDFs, audio or video?

Gemini 2.0 Flash accepts text, images, PDFs, audio and video; Grok 4.20 (Reasoning) accepts text, images and PDFs. Gemini 2.0 Flash handles the widest range of inputs.

Are any of these open source?

No. Gemini 2.0 Flash and Grok 4.20 (Reasoning) are proprietary and only available through APIs and apps.

Which is newer?

Grok 4.20 (Reasoning) is the newest, released Mar 9, 2026. Gemini 2.0 Flash came out Dec 11, 2024. Knowledge cutoff: Gemini 2.0 Flash Jun 2024.

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.

05 — Keep comparing

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