Grok 4.3 vs Gemini 3.1 Pro
xAI's Grok 4.3 is 37-79% cheaper than Gemini 3.1 Pro with identical 1M context windows.
Pricing data verified: Jun 9, 2026
| Specification | Grok 4.3 | Gemini 3.1 Pro |
|---|---|---|
| Input Price (per 1M tokens) | $1.25 | $2.00 |
| Output Price (per 1M tokens) | $2.50 | $12.00 |
| Context Window | 1M tokens | 1M tokens |
| Tier | Mid | Mid |
| Provider | xAI | |
| Input Savings | 37% cheaper | — |
| Output Savings | 79% cheaper | — |
| Cost at 1M input + 500K output | $2.50 | $8.00 |
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Which Model for Which Use Case?
Cost Optimization
Grok 4.3 is dramatically cheaper — 37% on input, 79% on output. For any workload where output volume is significant, Grok delivers massive savings with the same 1M context capacity.
Google Ecosystem Integration
Gemini 3.1 Pro integrates natively with Vertex AI, BigQuery, and other Google Cloud services. If your infrastructure is already on GCP, the ecosystem value may justify the premium price.
Real-Time Information
Grok 4.3 has access to real-time data from X/Twitter, making it ideal for social media analysis, news monitoring, and time-sensitive queries. Gemini relies on its training data cutoff.
Long Context Processing
Both models offer 1M token context windows — no tradeoff there. Grok at $2.50/mo for 1M input + 500K output is less than a third of Gemini's $8.00 for the same workload.
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Frequently Asked Questions
How much cheaper is Grok 4.3 compared to Gemini 3.1 Pro?
Grok 4.3 costs $1.25/M input and $2.50/M output. Gemini 3.1 Pro costs $2.00/M input and $12.00/M output. Grok is 37% cheaper on input and 79% cheaper on output. For a workload of 1M input + 500K output tokens/month, Grok costs $2.50 vs Gemini's $8.00 — saving you $5.50/month (69%).
How does Grok 4.3 quality compare to Gemini 3.1 Pro?
Both are mid-tier models with 1M token context windows. Gemini 3.1 Pro leverages Google's extensive training infrastructure and is strong at multilingual tasks, reasoning, and code. Grok 4.3 from xAI excels at real-time information (connected to X/Twitter), conversational tasks, and creative generation. Quality depends on your specific use case — both handle most production workloads well.
Do Grok 4.3 and Gemini 3.1 Pro have the same context window?
Yes, both models offer 1M token context windows. This makes the comparison purely about price and quality — there's no context tradeoff. Given Grok 4.3's 37-79% price advantage, it offers compelling value for tasks where context capacity is equal.
When should I choose Grok 4.3 over Gemini 3.1 Pro?
Choose Grok 4.3 when: (1) you want 37-79% cost savings with same 1M context, (2) you need real-time data access from X/Twitter, (3) you prefer xAI's API ecosystem. Choose Gemini 3.1 Pro when: (1) you need Google's ecosystem integration (Vertex AI, BigQuery), (2) your tasks require Google's specific multilingual strengths, (3) you need tight integration with other Google Cloud services.