Google: Gemini 2.5 Pro vs MoonshotAI: Kimi K3.1 Pro
Neither wins outright: Google: Gemini 2.5 Pro is the pick when cost matters at scale, MoonshotAI: Kimi K3.1 Pro when you generate long outputs in one go.
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
Workload (per month)
Google: Gemini 2.5 Pro
MoonshotAI: Kimi K3.1 Pro
Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$294
$350
Google: Gemini 2.5 Pro saves $56.25
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$250
$340
Google: Gemini 2.5 Pro saves $90.00
Coding / tool-using agent
2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens)
$270
$360
Google: Gemini 2.5 Pro saves $90.00
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$160
$220
Google: Gemini 2.5 Pro saves $60.00
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$72.50
$110
Google: Gemini 2.5 Pro saves $37.50
Capabilities side by side
Capability
Google: Gemini 2.5 Pro
MoonshotAI: Kimi K3.1 Pro
What it lets you do
Tool / function calling
✓ Yes
✓ Yes
call your APIs and run agent loops
Structured output (JSON schema)
✓ Yes
✓ Yes
return JSON that validates against your schema
Reasoning / thinking mode
✓ Yes
✓ Yes
spend extra tokens thinking before answering hard problems
Image input
✓ Yes
✓ Yes
read screenshots, charts and scanned pages
Audio input
✓ Yes
—
take speech or audio directly
File / PDF input
✓ Yes
—
accept documents without your own parsing step
Image output
—
—
generate images, not just text
Built-in web search
✓ Yes
—
answer from live web results
Seed (reproducible sampling)
✓ Yes
—
repeat a generation for tests and evals
Log-probabilities
—
—
read token confidence for classification and scoring
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
Google: Gemini 2.5 Pro: price unchanged since we started tracking it on 2026-03-10.
MoonshotAI: Kimi K3.1 Pro: price unchanged since we started tracking it on 2026-10-24.
Which should you choose?
Choose Google: Gemini 2.5 Pro if…
cost matters at scale — it is 14% cheaper on a typical 3:1 input/output mix ($294 vs $350 a month for 50,000 support chats)
you need audio input — to take speech or audio directly; MoonshotAI: Kimi K3.1 Pro does not advertise it
you need file / PDF input — to accept documents without your own parsing step; MoonshotAI: Kimi K3.1 Pro does not advertise it
you need built-in web search — to answer from live web results; MoonshotAI: Kimi K3.1 Pro does not advertise it
you need seed (reproducible sampling) — to repeat a generation for tests and evals; MoonshotAI: Kimi K3.1 Pro does not advertise it
Choose MoonshotAI: Kimi K3.1 Pro if…
you generate long outputs in one go — up to 944K tokens (about 707,800 words) per response
you want the newer model — released 2026-10-23, 16 months after the other
Frequently asked questions
Is Google: Gemini 2.5 Pro better than MoonshotAI: Kimi K3.1 Pro?
Neither wins outright: Google: Gemini 2.5 Pro is the pick when cost matters at scale, MoonshotAI: Kimi K3.1 Pro when you generate long outputs in one go. In short: Google: Gemini 2.5 Pro when cost matters at scale, you need audio input, you need file / PDF input, you need built-in web search, you need seed (reproducible sampling); MoonshotAI: Kimi K3.1 Pro when you generate long outputs in one go, you want the newer model.
Which is cheaper, Google: Gemini 2.5 Pro or MoonshotAI: Kimi K3.1 Pro?
Google: Gemini 2.5 Pro is cheaper: $3.44 vs $4.00 per 1M tokens at a typical 3:1 input/output mix, 14% less. For 50,000 support conversations a month that is $294 against $350.
How much do Google: Gemini 2.5 Pro and MoonshotAI: Kimi K3.1 Pro cost per million tokens?
Google: Gemini 2.5 Pro costs $1.25 per 1M input tokens and $10.00 per 1M output tokens; MoonshotAI: Kimi K3.1 Pro costs $2.00 input and $10.00 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, Google: Gemini 2.5 Pro or MoonshotAI: Kimi K3.1 Pro?
Both take 1.0M tokens per request — roughly 1,573 pages of text.
Do Google: Gemini 2.5 Pro and MoonshotAI: Kimi K3.1 Pro support function calling and JSON output?
Gemini 2.5 Pro is Google’s state-of-the-art AI model designed for advanced reasoning, coding, mathematics, and scientific tasks. It employs “thinking” capabilities, enabling it to reason through responses with enhanced accuracy...
Kimi K3.1 Pro is Moonshot AI's flagship open-weight multimodal reasoning model and a post-trained successor to Kimi K3, with a 1M-token context window. It is built for long-horizon coding, 3D...