High-volume, cost-sensitive work
Choose Gemini 3.8 Flash
Gemini 3.8 Flash costs 4% less on a typical mix of three input tokens for every output token ($1.50 against $1.56 per million tokens).
Gemini 3.8 Flash vs Grok 4.3: price, context and capabilities
Choose Gemini 3.8 Flash for high-volume, cost-sensitive work, reused prompts and documents (RAG, agents), the hardest reasoning tasks, reasoning over long documents and the latest release. Choose Grok 4.3 for writing and code generation.
In short
- Gemini 3.8 Flash is 4% cheaper than Grok 4.3 at the headline price ($1.50 / 1M tokens vs $1.56 / 1M tokens).
- Gemini 3.8 Flash reads more per request: 1.05M tokens against 1M.
- Gemini 3.8 Flash is the newer model (September 2026, against Apr 30, 2026).
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose Grok 4.3
Grok 4.3 charges $2.50 per million output tokens, against $3.75 for Gemini 3.8 Flash. Output dominates the bill when answers are long.
Reused prompts and documents (RAG, agents)
Choose Gemini 3.8 Flash
Gemini 3.8 Flash charges $0.08 per million cached input tokens, against $0.20 for Grok 4.3.
Hardest reasoning tasks
Choose Gemini 3.8 Flash
Gemini 3.8 Flash scores 40.9 on the Artificial Analysis Intelligence Index, against 24.9 for Grok 4.3.
Reasoning over long documents
Choose Gemini 3.8 Flash
Gemini 3.8 Flash scores 81.3% on Long-context reasoning (AA-LCR), against 73% for Grok 4.3.
Latest release
Choose Gemini 3.8 Flash
Gemini 3.8 Flash is the newer release (September 2026, against Apr 30, 2026 for Grok 4.3).
Monthly cost at three volumes
| Volume | Gemini 3.8 Flash | Grok 4.3 | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $1.69 | $1.88 | Gemini 3.8 Flash, $0.19 less |
| Production: 20M input, 5M output tokens | $33.75 | $37.50 | Gemini 3.8 Flash, $3.75 less |
| Scale: 500M input, 100M output tokens | $750.00 | $875.00 | Gemini 3.8 Flash, $125.00 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Gemini 3.8 Flash | Grok 4.3 | |
|---|---|---|
| Provider | xAI | |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $1.50 / 1M tokens | $1.56 / 1M tokens |
| Input | $0.75 / 1M tokens | $1.25 / 1M tokens |
| Output | $3.75 / 1M tokens | $2.50 / 1M tokens |
| Cached input | $0.075 / 1M tokens | $0.20 / 1M tokens |
| Context window | 1.05M | 1M |
| Max output | 66k | No data |
| Released | September 2026 | Apr 30, 2026 |
| Knowledge cutoff | No data | No data |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API |
| API model id | gemini-3.8-flash | grok-4.3 |
Benchmarks side by side
Leader in bold.
| Benchmark | Gemini 3.8 Flash | Grok 4.3 |
|---|---|---|
| Intelligence Index | 40.9 | 24.9 |
| SciCode | 56.6% | 48.3% |
| GPQA Diamond | 95.3% | 90.1% |
| Humanity's Last Exam | 47.8% | 37.2% |
| MMMU-Pro (visual reasoning) | 85.6% | 78.1% |
| Long-context reasoning (AA-LCR) | 81.3% | 73% |
| Terminal-Bench Hard | No data | 37.9% |
| IFBench (instruction following) | No data | 81.3% |
| τ²-Bench (agentic tool use) | No data | 97.7% |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose Gemini 3.8 Flash or Grok 4.3?
Choose Gemini 3.8 Flash for high-volume, cost-sensitive work, reused prompts and documents (RAG, agents), the hardest reasoning tasks, reasoning over long documents and the latest release. Choose Grok 4.3 for writing and code generation.
Which is cheaper, Gemini 3.8 Flash or Grok 4.3?
Gemini 3.8 Flash is 4% cheaper than Grok 4.3 at the headline price ($1.50 / 1M tokens vs $1.56 / 1M tokens).
Which has the larger context window, Gemini 3.8 Flash or Grok 4.3?
Gemini 3.8 Flash reads more per request: 1.05M tokens against 1M.
What is the difference between Gemini 3.8 Flash and Grok 4.3?
Gemini 3.8 Flash is made by Google and Grok 4.3 by xAI. Gemini 3.8 Flash is 4% cheaper than Grok 4.3 at the headline price ($1.50 / 1M tokens vs $1.56 / 1M tokens). Gemini 3.8 Flash reads more per request: 1.05M tokens against 1M. Gemini 3.8 Flash is the newer model (September 2026, against Apr 30, 2026).
How much do Gemini 3.8 Flash and Grok 4.3 cost per month?
At 20 million input and 5 million output tokens a month, Gemini 3.8 Flash costs $33.75 and Grok 4.3 costs $37.50, at standard rates.
Which is newer, Gemini 3.8 Flash or Grok 4.3?
Gemini 3.8 Flash was released on September 2026 and Grok 4.3 on Apr 30, 2026.