Gemini 2.5 Flash vs GPT-5 mini: API pricing compared

Head-to-head on price — the mid-tier value picks. On a mixed 10K-input / 2K-output request, GPT-5 mini is about 1.2× cheaper. The full picture below.

List prices side by side

Gemini 2.5 FlashGPT-5 mini
ProviderGoogleOpenAI
Input $/MTok$0.3$0.25
Cached input $/MTok$0.03 (90% off)$0.025 (90% off)
Output $/MTok$2.5$2
Context window1024K tokens391K tokens
Max output64K tokens125K tokens

Gemini 2.5 Flash: Cached input also incurs $1.00/MTok/hour storage.

What each costs in practice

WorkloadInputOutputGemini 2.5 FlashGPT-5 mini
Short chat message500250$0.0008$0.0006
10-page document + summary7,000500$0.0034$0.0027
Agent / coding session50,00010,000$0.040$0.033
1M tokens in + 1M out1,000,0001,000,000$2.80$2.25

Price your exact token mix on each model's own page: the Gemini 2.5 Flash cost calculator and the GPT-5 mini cost calculator both take custom input/output counts and a requests-per-day figure.

About Gemini 2.5 Flash

Gemini 2.5 Flash is Google's stated price-performance pick within the Gemini 2.5 family: a low-latency, high-volume model that still supports reasoning, rather than a stripped-down budget option. It keeps the family's full multimodal intake — text, images, audio, video — and the million-token-class context window, which is unusual generosity at its price tier.

Google has since shipped Flash models in newer generations, but this release stays available as a stable workhorse, and its combination of low rates and real reasoning keeps it a common default for production pipelines.

About GPT-5 mini

GPT-5 mini is the mid-size member of the GPT-5 family, offered by OpenAI for well-defined tasks that need solid reasoning without flagship cost — the role previously held by o4-mini, which OpenAI lists mini as succeeding. It handles text and image input with text output, and keeps the same reasoning-effort controls and tool integrations as its larger sibling.

The design intent is precision at a price: workloads with clear instructions and bounded scope — support automation, structured extraction, code review at scale — are its home ground, with the full family context window available when documents run long.

Frequently asked questions

Which is cheaper, Gemini 2.5 Flash or GPT-5 mini?

On a mixed workload (10K input / 2K output tokens per request), GPT-5 mini costs $0.0065 per request versus $0.0080 for Gemini 2.5 Flash — about 1.2× less. List rates: Gemini 2.5 Flash is $0.3/M input and $2.5/M output; GPT-5 mini is $0.25/M input and $2/M output.

What does a typical chat message cost on Gemini 2.5 Flash vs GPT-5 mini?

A short chat message (about 500 input and 250 output tokens) costs roughly $0.0008 with Gemini 2.5 Flash and $0.0006 with GPT-5 mini. At 1,000 messages a day that is about $23.25 versus $18.75 per month.

Do Gemini 2.5 Flash and GPT-5 mini have the same context window?

No. Gemini 2.5 Flash accepts up to 1024K tokens of input; GPT-5 mini accepts up to 391K. For workloads built around very large prompts, that difference can matter as much as the per-token rates.

Related

Compare all models at once ·Gemini 2.5 Flash pricing in detail ·GPT-5 mini pricing in detail ·Count tokens in your prompt

Last updated 2026-09-03. Prices verified against each provider's official pricing page; see the methodology.