AI model comparison

Kimi K2 0905 vs Gemini 2.5 Flash

Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.

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Moonshot AI

Kimi K2 0905

Kimi K2 0905 is the September update of [Kimi K2 0711](moonshotai/kimi-k2).

Input / 1M
$0.60
Output / 1M
$2.50
Context
262K

Gemini 2.5 Flash is Google's state-of-the-art workhorse model, specifically designed for advanced reasoning, coding, mathematics, and scientific tasks.

Gemini 2.5 Flash is scheduled to be retired on October 20, 2026. Consider Gemini 3.8 Flash instead.

Input / 1M
$0.30
Output / 1M
$2.50
Context
1.05M

At a glance

Quick verdict

How the two models stack up on the things people ask about most.

Lower price

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Gemini 2.5 Flash

1.3x cheaper for a typical chat

Higher intelligence score

google logo

Gemini 2.5 Flash

15.5 vs 15.3 on Artificial Analysis

Larger context window

google logo

Gemini 2.5 Flash

1.05M vs 262K tokens

Newer release

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Kimi K2 0905

Released September 4, 2025

Benchmarks

Benchmark scores

Independent scores from Artificial Analysis. Higher is better.

Intelligence index

moonshotai logoKimi K2 090515.3
google logoGemini 2.5 Flash15.5

Coding index

moonshotai logoKimi K2 0905Not available
google logoGemini 2.5 FlashNot available

Agentic index

moonshotai logoKimi K2 0905Not available
google logoGemini 2.5 FlashNot available

Pricing

Kimi K2 0905 vs Gemini 2.5 Flash API pricing

Per-token API rates. Cheaper option highlighted.

Metricmoonshotai logoKimi K2 0905google logoGemini 2.5 Flash
Input tokensPer 1M tokens$0.60$0.30
Output tokensPer 1M tokens$2.50$2.50
Cached input (read)Per 1M tokensNot available$0.03
Cache writePer 1M tokensNot available$0.08
Web searchPer requestNot available$0.014

What it costs in practice

Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.

Chat message

2K in, 500 out

moonshotai logoKimi K2 0905$2.45
google logoGemini 2.5 Flash$1.85

Coding task

30K in, 4K out

moonshotai logoKimi K2 0905$28
google logoGemini 2.5 Flash$19$10.90 cached

Long document summary

150K in, 2K out

moonshotai logoKimi K2 0905$95
google logoGemini 2.5 Flash$50$9.50 cached

Specs

Context window and capabilities

How much each model can read, how much it can write, and what it accepts as input.

Metricmoonshotai logoKimi K2 0905google logoGemini 2.5 Flash
Context window262K tokens1.05M tokens
Max output98K tokens66K tokens
Input typesTextAudio, File, Image, Text, Video
Output typesTextText
Reasoning effort levelsNot availableNot available
Default reasoning effortNot availableNot available
Release dateSeptember 4, 2025June 17, 2025

Features

Supported features

API features available for each model.

Metricmoonshotai logoKimi K2 0905google logoGemini 2.5 Flash
Tool callingSupportedSupported
Structured outputsSupportedSupported
JSON modeSupportedSupported
ReasoningNot supportedSupported
TemperatureSupportedSupported
Stop sequencesSupportedSupported
Deterministic seedSupportedSupported
Verbosity controlNot supportedNot supported

Our take

Gemini 2.5 Flash is 1.3x cheaper for a typical chat. Gemini 2.5 Flash scores higher on the Artificial Analysis Intelligence Index (15.5 vs 15.3). Gemini 2.5 Flash has the larger context window (1.05M vs 262K tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.

FAQ

Frequently asked questions

Is Kimi K2 0905 or Gemini 2.5 Flash cheaper?

Gemini 2.5 Flash is cheaper for a typical chat (2K input tokens and 500 output tokens). Gemini 2.5 Flash costs $0.30 per 1M input tokens and $2.50 per 1M output tokens, while Kimi K2 0905 costs $0.60 per 1M input tokens and $2.50 per 1M output tokens.

Which has a bigger context window, Kimi K2 0905 or Gemini 2.5 Flash?

Gemini 2.5 Flash supports up to 1.05M tokens of context, compared with 262K for Kimi K2 0905.

Is Kimi K2 0905 smarter than Gemini 2.5 Flash?

On the Artificial Analysis Intelligence Index, Kimi K2 0905 scores 15.3 and Gemini 2.5 Flash scores 15.5, putting Gemini 2.5 Flash ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.

Can I use Kimi K2 0905 and Gemini 2.5 Flash at the same time?

Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Kimi K2 0905 and Gemini 2.5 Flash answer side by side and keep the better response.

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Why choose? Ask both.

Send one prompt to Kimi K2 0905 and Gemini 2.5 Flash at the same time. Compare the answers side by side and keep the best one.