Gemini 3 Flash vs Grok 4.5: Specs & Benchmark Comparison

Gemini 3 Flash is developed by Google, while Grok 4.5 comes from xAI. Gemini 3 Flash was released in December 2025, and Grok 4.5 followed 7 months later in July 2026.

We have 23 benchmark results for Gemini 3 Flash and 15 benchmark results for Grok 4.5, but they overlap on a single test: GPQA, where Grok 4.5 scores 93.0% against 90.0%.

Gemini 3 Flash is the cheaper API at $0.50 per million input tokens and $3 per million output tokens, roughly 4 times cheaper than Grok 4.5 at $2 and $6. Gemini 3 Flash takes the larger context window at 1M tokens, compared with 500K for Grok 4.5. Gemini 3 Flash accepts text, images, audio, and video as input, while Grok 4.5 accepts text and images.

CharacteristicGemini 3 FlashGrok 4.5
CompanyGooglexAI
Release DateDecember 16, 2025July 16, 2026
Parameters
MultimodalYesYes
Context (input)1.0M500K
Context (output)66K
Input Price / 1M$0.50$2.00
Output Price / 1M$3.00$6.00
Average Score63.0%52.9%
Benchmarks
GPQA90.0%93.0%

Visual Benchmark Comparison

Gemini 3 Flash
Grok 4.5
GPQA0.9 vs 0.9
0.9
0.9

Verdict

Gemini 3 Flash leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: Gemini 3 Flash — 0.6, Grok 4.5 — 0.5.

API Cost

Gemini 3 Flash is 2.3x cheaper: input $0.50/1M vs $2.00/1M tokens.

Context Window

Gemini 3 Flash supports a larger context: 1M vs 500K tokens.

Recency

Grok 4.5 is newer: released 7/16/2026 vs 12/16/2025.

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Frequently Asked Questions

Which is better for coding — Gemini 3 Flash or Grok 4.5?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — Gemini 3 Flash or Grok 4.5?
Gemini 3 Flash is cheaper for input: $0.50 per 1M tokens vs $2.00.
Which has a larger context window — Gemini 3 Flash or Grok 4.5?
Gemini 3 Flash supports a larger context: 1,048,576 tokens vs 500,000.

The Gemini 3 Flash and Grok 4.5 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Gemini 3 Flash or Grok 4.5 page. See also the complete list of AI model comparisons.