Gemini 3.8 Flash vs Grok-4 Fast Non-Reasoning
Comparing Gemini 3.8 Flash and Grok-4 Fast Non-Reasoning across benchmarks, pricing, and capabilities.
Google · xAI · Updated for 2026
Which is better?
Gemini 3.8 Flash and Grok-4 Fast Non-Reasoning trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
On price, Grok-4 Fast Non-Reasoning is roughly 5.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok-4 Fast Non-Reasoning also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Gemini 3.8 Flash
- you want the most recent training data — it shipped Sep 2026
Choose Grok-4 Fast Non-Reasoning
- cost matters — it's about 5.5x cheaper per token
- you process long inputs — it offers a 2,000,000 token context window
At a glance
The differences that matter most.
Individual benchmarks
13 reported for Gemini 3.8 Flash · 0 for Grok-4 Fast Non-Reasoning
Gemini 3.8 Flash and Grok-4 Fast Non-Reasoningdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 3.8 Flash ($0.75/1M tokens) is 3.8x more expensive than Grok-4 Fast Non-Reasoning ($0.20/1M tokens).
For output processing, Gemini 3.8 Flash ($3.75/1M tokens) is 7.5x more expensive than Grok-4 Fast Non-Reasoning ($0.50/1M tokens).
In conclusion, Gemini 3.8 Flash is more expensive than Grok-4 Fast Non-Reasoning.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok-4 Fast Non-Reasoning accepts 2,000,000 input tokens compared to Gemini 3.8 Flash's 1,048,576 tokens. Gemini 3.8 Flash can generate longer responses up to 65,536 tokens, while Grok-4 Fast Non-Reasoning is limited to 30,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Gemini 3.8 Flash and Grok-4 Fast Non-Reasoning support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Gemini 3.8 Flash
Grok-4 Fast Non-Reasoning
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Gemini 3.8 Flash was released on 2026-09-02, while Grok-4 Fast Non-Reasoning was released on 2025-08-28.
Gemini 3.8 Flash is 12 months newer than Grok-4 Fast Non-Reasoning.
Sep 2, 2026
2 weeks ago
1.0yr newerAug 28, 2025
1.1 years ago
Knowledge Cutoff
When training data ends
Gemini 3.8 Flash has a documented knowledge cutoff of 2026-03-31, while Grok-4 Fast Non-Reasoning's cutoff date is not specified.
We can confirm Gemini 3.8 Flash's training data extends to 2026-03-31, but cannot make a direct comparison without Grok-4 Fast Non-Reasoning's cutoff date.
Mar 2026
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Provider Availability
Gemini 3.8 Flash is available from Google. Grok-4 Fast Non-Reasoning is available from xAI.
Gemini 3.8 Flash
Grok-4 Fast Non-Reasoning
Outputs Comparison
Judge for yourself.
Run your own prompts against Gemini 3.8 Flash and Grok-4 Fast Non-Reasoning side-by-side, then vote on the output you prefer.
FAQ
Common questions about Gemini 3.8 Flash vs Grok-4 Fast Non-Reasoning.