Kimi K3.1 Pro API pricing

Official Kimi list price, last checked Oct 29, 2026. Updated Oct 29, 2026.

Quick answer

Kimi K3.1 Pro costs $2 per 1M input tokens and $10 per 1M output tokens, cached input at $0.20, and a 1M-token context window, per Kimi's official pricing page (checked Oct 29, 2026). It's a premium-priced model: number 65 of 77 by blended price ($4 per 1M tokens at a 3 to 1 input to output mix). On LMArena's Code Arena it ranks #6 of 50 models we price (relative score 57 out of 100). Cheaper pick: DeepSeek V4.1 Flash scores 46 against 57 on the same board at $0.525 blended, 7.6x less.

Kimi K3.1 Pro price per million tokens

Kimi K3.1 Pro price per million tokens	USD
Input	$2
Cached input	$0.20
Output	$10
Blended, 3 parts input to 1 part output	$4
Context window	1M tokens

Official note from Kimi: Flat price across the 1M window. Cache writes cost $2 (5-minute) or $4 (1-hour).

What Kimi K3.1 Pro costs for real work

List-price estimates for a month, no discounts. Our math, not a quote: change the token counts in the plan vs API calculator.

Workload	Tokens a month	Kimi K3.1 Pro	GPT-6.1 Sol	GPT-6.1 Terra
Light: a side project or personal assistant	2M in, 0.5M out	$9.00	$9.00	$4.50
Medium: a small team or one product feature	20M in, 5M out	$90.00	$90.00	$45.00
Heavy: a production app	200M in, 50M out	$900	$900	$450
Medium with 80% of input cached	20M in (16M cached), 5M out	$61.20	$59.60	$29.80

How Kimi K3.1 Pro ranks on LMArena

Relative score: 100 is the top model we price on that board. Rank is among the models in our price table, not the full leaderboard.

Board	Rank	Score /100	Rating
Coding (Code Arena)	#6 of 50	57	1694.6

Closest rivals to Kimi K3.1 Pro

The models nearest in price, other makers first. Ranks are on Code Arena, where we have them.

Model	In / out	Blended	Coding rank	Verdict
GPT-6.1 Sol OpenAI	$2 / $10	$4	#4	GPT-6.1 Sol wins: same price, higher score. Compare
GPT-6 Sol OpenAI	$2 / $10	$4	#9	Kimi K3.1 Pro wins: same price, higher score. Compare
Claude Sonnet 5.5 Anthropic	$2 / $10	$4	#3	Claude Sonnet 5.5 wins: same price, higher score. Compare
Gemini 4 Argon Google	$2 / $10	$4	#8	Kimi K3.1 Pro wins: same price, higher score. Compare

Cheaper alternatives to Kimi K3.1 Pro

At least 40% cheaper blended, best LMArena score first.

Model	In / out	Blended	Coding rank	Verdict
GPT-6.1 Terra OpenAI	$1 / $5	$2	#11	GPT-6.1 Terra for price, Kimi K3.1 Pro for quality. Compare
DeepSeek V4.1 Flash DeepSeek	$0.30 / $1.20	$0.525	#12	DeepSeek V4.1 Flash for price, Kimi K3.1 Pro for quality. Compare
Muse Spark 1.3 Meta	$1.25 / $4.25	$2	#14	Muse Spark 1.3 for price, Kimi K3.1 Pro for quality. Compare

FAQ

How much does the Kimi K3.1 Pro API cost per million tokens?

$2 per 1M input tokens and $10 per 1M output tokens, plus $0.20 per 1M for cached input, as of Oct 29, 2026. A typical 3 to 1 input to output mix works out to $4 per 1M tokens.

Does Kimi K3.1 Pro charge more for long prompts?

Kimi doesn't list a long-prompt surcharge for Kimi K3.1 Pro. Its pricing note says: Flat price across the 1M window. Cache writes cost $2 (5-minute) or $4 (1-hour).

Is Kimi K3.1 Pro cheaper than GPT-6.1 Sol?

About the same. A medium month (20M input and 5M output tokens) costs $90.00 on Kimi K3.1 Pro and $90.00 on GPT-6.1 Sol at list price. On Code Arena, Kimi K3.1 Pro ranks #6 and GPT-6.1 Sol #4.

How does Kimi K3.1 Pro rank on LMArena?

On Code Arena it is #6 of 50 models we price, with a relative score of 57 out of 100.

What is a cheaper alternative to Kimi K3.1 Pro?

GPT-6.1 Terra costs $1 in and $5 out per 1M tokens, about 2.0x less blended, and scores 49 on Code Arena against 57 for Kimi K3.1 Pro.

Where does this Kimi K3.1 Pro price come from?

From Kimi's official pricing page, which we check every day. This page was last checked Oct 29, 2026.