Model Comparison

Gemini 3.5 Flash-Lite vs Grok-4 HeavyWhich is better in 2026?

Comparing Gemini 3.5 Flash-Lite and Grok-4 Heavy across benchmarks, pricing, and capabilities.

Verdict: Gemini 3.5 Flash-Lite vs Grok-4 Heavy — which is better?

Gemini 3.5 Flash-Lite (by Google) and Grok-4 Heavy (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.

Choose Gemini 3.5 Flash-Lite if…

  • you want predictable pricing at $0.30/M input and $2.50/M output

Choose Grok-4 Heavy if…

  • you are already invested in the xAI ecosystem

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Gemini 3.5 Flash-Lite and Grok-4 Heavydon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Gemini 3.5 Flash-Lite specifies input context (1,048,576 tokens). Only Gemini 3.5 Flash-Lite specifies output context (65,536 tokens).

Google
Gemini 3.5 Flash-Lite
Input1,048,576 tokens
Output65,536 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Tue Jul 21 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 3.5 Flash-Lite and Grok-4 Heavy support multimodal inputs.

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

Gemini 3.5 Flash-Lite

Text
Images
Audio
Video

Grok-4 Heavy

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-Lite

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3.5 Flash-Lite was released on 2026-07-21, while Grok-4 Heavy's release date is not specified.

We can confirm Gemini 3.5 Flash-Lite's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Gemini 3.5 Flash-Lite

Jul 21, 2026

0 days ago

Grok-4 Heavy

—

Knowledge Cutoff

When training data ends

Gemini 3.5 Flash-Lite has a knowledge cutoff of 2026-03-31, while Grok-4 Heavy has a cutoff of 2024-12-31.

Gemini 3.5 Flash-Lite has more recent training data (up to 2026-03-31), making it potentially better informed about events through that date compared to Grok-4 Heavy (2024-12-31).

Gemini 3.5 Flash-Lite

Mar 2026

1.3 yr newer
Grok-4 Heavy

Dec 2024

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google
Larger context window (1,048,576 tokens)
xAI

No standout differentiators in the data we have for this pair.

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 3.5 Flash-Lite and Grok-4 Heavy side-by-side, then vote on the output you prefer.

Gemini 3.5 Flash-Lite
✓ Preferred
Grok-4 Heavy
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 3.5 Flash-Lite
xAI
Grok-4 Heavy

FAQ

Common questions about Gemini 3.5 Flash-Lite vs Grok-4 Heavy.

Which is better, Gemini 3.5 Flash-Lite or Grok-4 Heavy?

Gemini 3.5 Flash-Lite (Google) and Grok-4 Heavy (xAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Gemini 3.5 Flash-Lite compare to Grok-4 Heavy in benchmarks?

Gemini 3.5 Flash-Lite scores CharXiv-R: 76.5%, OSWorld-Verified: 74.0%, SWE-Bench Pro: 54.2%, Terminal-Bench 2.1: 54.0%, MLE-Bench: 39.2%. Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%.

What are the context window sizes for Gemini 3.5 Flash-Lite and Grok-4 Heavy?

Gemini 3.5 Flash-Lite supports 1.0M tokens and Grok-4 Heavy supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

Who makes Gemini 3.5 Flash-Lite and Grok-4 Heavy?

Gemini 3.5 Flash-Lite is developed by Google and Grok-4 Heavy is developed by xAI.

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