Comparison · prices as of 2026-07-04 · re-verified 2026-08-18
GPT-5 mini vs Gemini 2.5 Flash
On price alone, GPT-5 mini (OpenAI) runs about 19% cheaper than Gemini 2.5 Flash for a typical chat workload (2K input + 500 output tokens, 1,000 requests/day). Whether that's the right trade depends on the capability gap — the breakdown below shows where each one wins.
Price per million tokens
| Spec | GPT-5 mini | Gemini 2.5 Flash |
|---|---|---|
| Input / MTok | $0.25 | $0.30 |
| Output / MTok | $2 | $2.50 |
| Context window | 400K | 1M |
| Max output | 128K | 66K |
| Class | workhorse | workhorse |
Estimated monthly cost by workload
Same models, three realistic usage levels. The gap between them scales with volume, so the right pick can change as you grow.
| Workload | GPT-5 mini | Gemini 2.5 Flash | Cheaper |
|---|---|---|---|
| Light — chatbot 0.5K in / 0.2K out · 200 req/day | $3.15 | $3.90 | GPT-5 mini |
| Typical — assistant 2K in / 0.5K out · 1K req/day | $45.00 | $55.50 | GPT-5 mini |
| Heavy — RAG / agent 8K in / 2K out · 5K req/day | $900 | $1,110 | GPT-5 mini |
Which should you pick?
- Cheapest overall: GPT-5 mini — about 19% less per month on a typical assistant workload.
- GPT-5 mini is cheaper on both input and output, so it stays cheaper whether your workload is prompt-heavy or generation-heavy.
- Largest context window: Gemini 2.5 Flash at 1M tokens vs 400K — the one to pick if you feed in whole documents or codebases.
Frequently asked questions
Is GPT-5 mini or Gemini 2.5 Flash cheaper?
GPT-5 mini is cheaper — roughly 19% less per month on a typical assistant workload (2K input + 500 output tokens, 1,000 requests/day).
What do GPT-5 mini and Gemini 2.5 Flash cost per million tokens?
GPT-5 mini is $0.25 per million input tokens and $2 per million output. Gemini 2.5 Flash is $0.30 input and $2.50 output. Prices are first-party API list rates as of 2026-07-04.
Which has the larger context window, GPT-5 mini or Gemini 2.5 Flash?
Gemini 2.5 Flash does, at 1M tokens versus 400K for GPT-5 mini.
When should I choose Gemini 2.5 Flash over GPT-5 mini?
Both are workhorse-class models, so choose Gemini 2.5 Flash when it measurably wins on your own evals or you prefer its provider (Google); otherwise GPT-5 mini does the same job for less.
Related comparisons
Sources: OpenAI pricing · Google pricing. Run your own numbers in the cost calculator.