Model Comparison

Gemini 3.5 Flash vs Grok 4.5Which is better in 2026?

Grok 4.5 significantly outperforms across most benchmarks. Grok 4.5 is 1.1x cheaper per token.

Verdict: Gemini 3.5 Flash vs Grok 4.5 — which is better?

Gemini 3.5 Flash (by Google) and Grok 4.5 (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Gemini 3.5 Flash outperforms in 0 benchmarks, while Grok 4.5 is better at 2 benchmarks (GDPval-AA, SWE-Bench Pro). Grok 4.5 significantly outperforms across most benchmarks.

On price, Grok 4.5 is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 3.5 Flash also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 3.5 Flash if…

  • you process long inputs — it offers a 1,048,576 token context window

Choose Grok 4.5 if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
  • cost matters — it's about 1.1x cheaper per token
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Gemini 3.5 Flash outperforms in 0 benchmarks, while Grok 4.5 is better at 2 benchmarks (GDPval-AA, SWE-Bench Pro).

Grok 4.5 significantly outperforms across most benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok 4.5 costs less

For input processing, Gemini 3.5 Flash ($1.50/1M tokens) is 1.3x cheaper than Grok 4.5 ($2.00/1M tokens).

For output processing, Gemini 3.5 Flash ($9.00/1M tokens) is 1.5x more expensive than Grok 4.5 ($6.00/1M tokens).

In conclusion, Gemini 3.5 Flash is more expensive than Grok 4.5.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Fri Jul 17 2026 • llm-stats.com
Google
Gemini 3.5 Flash
Input tokens$1.50
Output tokens$9.00
Best providerGoogle
xAI
Grok 4.5
Input tokens$2.00
Output tokens$6.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 3.5 Flash accepts 1,048,576 input tokens compared to Grok 4.5's 500,000 tokens. Only Gemini 3.5 Flash specifies output context (65,536 tokens).

Google
Gemini 3.5 Flash
Input1,048,576 tokens
Output65,536 tokens
xAI
Grok 4.5
Input500,000 tokens
Output- tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 3.5 Flash and Grok 4.5 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 3.5 Flash

Text
Images
Audio
Video

Grok 4.5

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Gemini 3.5 Flash

Proprietary

Closed source

Grok 4.5

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3.5 Flash was released on 2026-05-19, while Grok 4.5 was released on 2026-07-08.

Grok 4.5 is 2 months newer than Gemini 3.5 Flash.

Gemini 3.5 Flash

May 19, 2026

1 months ago

Grok 4.5

Jul 8, 2026

1 weeks ago

1mo newer

Knowledge Cutoff

When training data ends

Gemini 3.5 Flash has a documented knowledge cutoff of 2026-01-31, while Grok 4.5's cutoff date is not specified.

We can confirm Gemini 3.5 Flash's training data extends to 2026-01-31, but cannot make a direct comparison without Grok 4.5's cutoff date.

Gemini 3.5 Flash

Jan 2026

Grok 4.5

—

Provider Availability

Gemini 3.5 Flash is available from Google. Grok 4.5 is available from xAI.

Gemini 3.5 Flash

google logo
Google
Input Price:Input: $1.50/1MOutput Price:Output: $9.00/1M

Grok 4.5

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google
Larger context window (1,048,576 tokens)
Less expensive input tokens
xAI
Less expensive output tokens
Higher GDPval-AA score (51.4% vs 45.7%)
Higher SWE-Bench Pro score (64.7% vs 55.1%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 3.5 Flash and Grok 4.5 side-by-side, then vote on the output you prefer.

Gemini 3.5 Flash
✓ Preferred
Grok 4.5
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 3.5 Flash
xAI
Grok 4.5

FAQ

Common questions about Gemini 3.5 Flash vs Grok 4.5.

Which is better, Gemini 3.5 Flash or Grok 4.5?

Grok 4.5 significantly outperforms across most benchmarks. Gemini 3.5 Flash is made by Google and Grok 4.5 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Gemini 3.5 Flash compare to Grok 4.5 in benchmarks?

Gemini 3.5 Flash scores CharXiv-R: 84.2%, MCP Atlas: 83.6%, MMMU-Pro: 83.6%, OSWorld-Verified: 78.4%, Terminal-Bench 2.0: 76.2%. Grok 4.5 scores GPQA: 93.0%, Terminal-Bench 2.1: 83.3%, Artificial Analysis Coding Agent Index v1.1: 76.0%, SWE-Bench Pro: 64.7%, AA-Omniscience Index: 63.0%.

Is Gemini 3.5 Flash cheaper than Grok 4.5?

Gemini 3.5 Flash is 1.3x cheaper for input tokens. Gemini 3.5 Flash costs $1.50/M input and $9.00/M output via google. Grok 4.5 costs $2.00/M input and $6.00/M output via xai.

What are the context window sizes for Gemini 3.5 Flash and Grok 4.5?

Gemini 3.5 Flash supports 1.0M tokens and Grok 4.5 supports 500K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 3.5 Flash and Grok 4.5?

Key differences include context window (1.0M vs 500K), input pricing ($1.50 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3.5 Flash and Grok 4.5?

Gemini 3.5 Flash is developed by Google and Grok 4.5 is developed by xAI.

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