Comparison · prices as of 2026-07-04 · re-verified 2026-08-18
GPT-5 nano vs Gemini 2.5 Flash-Lite
On price alone, GPT-5 nano (OpenAI) runs about 25% cheaper than Gemini 2.5 Flash-Lite 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 nano | Gemini 2.5 Flash-Lite |
|---|---|---|
| Input / MTok | $0.05 | $0.10 |
| Output / MTok | $0.40 | $0.40 |
| Context window | 400K | 1M |
| Max output | 128K | 66K |
| Class | fast / lightweight | fast / lightweight |
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 nano | Gemini 2.5 Flash-Lite | Cheaper |
|---|---|---|---|
| Light — chatbot 0.5K in / 0.2K out · 200 req/day | $0.63 | $0.78 | GPT-5 nano |
| Typical — assistant 2K in / 0.5K out · 1K req/day | $9.00 | $12.00 | GPT-5 nano |
| Heavy — RAG / agent 8K in / 2K out · 5K req/day | $180 | $240 | GPT-5 nano |
Which should you pick?
- Cheapest overall: GPT-5 nano — about 25% less per month on a typical assistant workload.
- GPT-5 nano 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-Lite at 1M tokens vs 400K — the one to pick if you feed in whole documents or codebases.
Frequently asked questions
Is GPT-5 nano or Gemini 2.5 Flash-Lite cheaper?
GPT-5 nano is cheaper — roughly 25% less per month on a typical assistant workload (2K input + 500 output tokens, 1,000 requests/day).
What do GPT-5 nano and Gemini 2.5 Flash-Lite cost per million tokens?
GPT-5 nano is $0.05 per million input tokens and $0.40 per million output. Gemini 2.5 Flash-Lite is $0.10 input and $0.40 output. Prices are first-party API list rates as of 2026-07-04.
Which has the larger context window, GPT-5 nano or Gemini 2.5 Flash-Lite?
Gemini 2.5 Flash-Lite does, at 1M tokens versus 400K for GPT-5 nano.
When should I choose Gemini 2.5 Flash-Lite over GPT-5 nano?
Both are fast / lightweight-class models, so choose Gemini 2.5 Flash-Lite when it measurably wins on your own evals or you prefer its provider (Google); otherwise GPT-5 nano does the same job for less.
Related comparisons
Sources: OpenAI pricing · Google pricing. Run your own numbers in the cost calculator.