Gemini 3.5 Flash vs GPT-5.4 Mini: which utility model is more economical?
GPT-5.4 Mini has half the standard input, output, and cache-read token prices. Increasing the cached input share does not create a crossover. Choose Gemini when its supported inputs or measured results justify the higher token cost.
Fast, lightweight multimodal models comparison.
Fast, lightweight models are the backbone of real-time applications. Gemini 3.5 Flash and GPT-5.4 Mini both target low-latency workflows with highly competitive pricing.
By TechCompare · Updated
Cost Comparison
Based on 100,000 input tokens (50% cached), 5,000 output tokens, and 100 requests.Provider USD token rates. Cache storage, cache writes, and other service fees aren't included.
Side-by-side specs
| Spec | Gemini 3.5 Flash | GPT-5.4 Mini |
|---|---|---|
| Input cost per 1M tokens | $1.50 | $0.75 (better on this spec) |
| Output cost per 1M tokens | $9.00 | $4.50 (better on this spec) |
| Cache reads per 1M tokens | $0.15 | $0.075 (better on this spec) |
| Batch discount | 50% | 50% |
How they differ
Gemini 3.5 Flash standard pricing is $1.50 per million input tokens, $9.00 output, and $0.15 cache reads. GPT-5.4 Mini charges $0.75 input, $4.50 output, and $0.075 cache reads. Both cache-read rates are 90% below uncached input, and both providers offer 50% batch token discounts. Google also charges $1 per million cached tokens per hour for storage. These official USD rates were checked on October 7, 2026.
Verdict
Mini wins every standard token price row at exactly half Gemini's rate. Both apply a 90% cache-read discount, so the same cached token share preserves that 2x relationship. With 100K input, half cached, and 5K output, Gemini costs $0.1275 and Mini costs $0.06375 before storage or other service charges. Their 50% batch discounts also preserve the token-price ratio. Google's separate cache storage charge can increase its total further. Compare accepted task results and actual billed usage rather than assuming identical tasks generate identical tokens.
Which should you pick?
Choose Gemini 3.5 Flash
Multimodal tasks involving audio/video/images, and standard low-latency transactions.
Choose GPT-5.4 Mini
Chat applications with highly repetitive, cached system prompts and long context history.