Everything about Gemini 2.5 Flash

What you need to know

Released on June 17, 2025, Gemini 2.5 Flash is one of the 14 Google DeepMind models tracked on this site. It is a closed model: you access it through an API, from Google DeepMind or one of the 33 providers listed on models.dev. It has a reasoning mode: it can "think" before answering, which helps with multi-step problems but uses more tokens, and therefore more money. That makes it more than a year old: successors may have shipped since.

We file it under mid-range models (34 models in this category on the site).

What do independent benchmarks say?

Epoch AI publishes a single result for Gemini 2.5 Flash on our basket's benchmarks: too few to compute a reliable capability index.

• Terminal-Bench (agent tasks in a terminal): 17.1% — the best tracked model, GPT-5.5, reaches 84.7%

What it costs

Gemini 2.5 Flash costs $0.30 per million input tokens and $2.5 per million output tokens (developer's price, checked on October 22, 2026).

To put it in perspective: reading 20,000 tokens (about thirty pages) and writing 2,000 costs roughly $0.011; a thousand of those tasks, $11.

That is 1.8 times cheaper than the median output price of mid-range models ($4.38).

Tokens read back from cache cost $0.03 per million, which helps an agent that keeps resending the same context.

To estimate your own budget, use the agent cost calculator.

Technical specifications

Its context window reaches 1,048,576 tokens, roughly 1,573 pages of text at 500 words per page: enough to load a whole book or a mid-sized codebase. A single answer can run to 65,536 tokens.

It accepts as input: text, image, audio, video and PDF. Its knowledge stops at January 2025: beyond that, it needs web search or your documents.

It can call tools (functions, APIs) and return structured JSON output, which makes it a possible foundation for an AI agent.

When to choose it

Given its category, Gemini 2.5 Flash is mainly aimed at a balance between quality and cost, for everyday uses that do not justify a frontier model.

Its very large context window makes it worth considering for analysing large sets of documents in a single request.

Before adopting it, test it on your own examples: benchmarks measure standard tasks, not your job.

Comparable models

In the same category, the models closest to Gemini 2.5 Flash are:

• Grok 4.3 (xAI, index 76.8)
• Grok 4.20 (Reasoning) (xAI, index 74.6)
• Gemini 3.5 Flash Lite (Google DeepMind, index 53.9)
• Seed 2.1 Turbo (ByteDance Seed, $2.5 per million output tokens)