Gemini 2.5 Flash-Lite vs GPT-5 nano
GPT-5 nano is cheaper for every workload modelled here.
List prices checked
Specifications and rates
| Property | Gemini 2.5 Flash-Lite | GPT-5 nano |
|---|---|---|
| Input per 1M | $0.100 | $0.050 |
| Output per 1M | $0.400 | $0.400 |
| Cached input per 1M | $0.025 | $0.0050 |
| Blended (3:1) | $0.175 | $0.138 |
| Context window | 1M | 400K |
| Max output | 66K | 128K |
| Inputs accepted | text, image, audio, video | text, image |
Source: Google pricing (May 2026) · OpenAI pricing (May 2026). Published list prices only — committed-use discounts, regional variation, and per-request charges are not included. Not yet independently re-checked against the vendor’s page.
Monthly cost by workload
Identical token volumes through both rate cards. Output-heavy profiles are where the ranking flips.
| Workload | Gemini 2.5 Flash-Lite | GPT-5 nano | Cheaper |
|---|---|---|---|
| In-app chat assistantA support or help assistant handling a few thousand conversations a month, with short prompts and short answers. | $4.00 | $3.00 | GPT-5 nanosaves $1.00/mo (25%) |
| RAG over documentsRetrieval-augmented answering where each request stuffs several retrieved passages into the prompt, so input dominates. | $36 | $21 | GPT-5 nanosaves $15/mo (42%) |
| Coding agentAn agentic loop that reads files and writes patches, generating heavy output and re-sending large context on every turn. | $80 | $60 | GPT-5 nanosaves $20/mo (25%) |
What each one is for
Gemini 2.5 Flash-Lite
by Google
Google's cheapest model, keeping the full million-token window and multimodal input. Priced to compete directly with GPT-5 nano on high-volume classification work.
GPT-5 nano
by OpenAI
The cheapest model OpenAI publishes, intended for classification, routing, and cleanup passes where the task is simple and the volume is enormous.
Common questions
- Is Gemini 2.5 Flash-Lite or GPT-5 nano cheaper in 2026?
- GPT-5 nano, for every workload modelled here. On a blended 3:1 basis it costs $0.138 per million tokens against Gemini 2.5 Flash-Lite's $0.175.
- Which has the larger context window?
- Gemini 2.5 Flash-Lite, at 1M tokens against 400K. A larger window only helps if you can afford to fill it — the cost of one full-context request is in the table above.
- Which is cheaper for output-heavy work like agents?
- GPT-5 nano, at $0.400 per million output tokens against $0.400. Reasoning tokens bill as output, so for agentic loops this axis usually decides the invoice regardless of what the input rates look like.
- What is not included in these figures?
- Batch-processing discounts, fine-tuning, long-context surcharges above a provider's standard tier, and any enterprise agreement. These are published pay-as-you-go list prices, checked against each provider's own pricing page on the date shown.
- Is switching from Gemini 2.5 Flash-Lite to GPT-5 nano worth it?
- On price alone it is about 21% cheaper on a blended basis. Whether that survives contact with your workload depends on output quality and on retry rate — a cheaper model that needs two attempts is not cheaper. Model the specific volumes in the calculator before you migrate.