DeepSeek V4.1 Flash 1017 vs Kimi K2.5: a data-driven comparison

Side-by-side comparison

Criterion	DeepSeek V4.1 Flash 1017	Kimi K2.5
Developer	DeepSeek	Moonshot AI
Released	October 17, 2026	January 27, 2026
Capability index	90.6 / 100	78.1 / 100
Input price	$0.15	$0.58
Output price	$0.60	$3
Cost of a typical task	$0.004	$0.018
Context window	1,048,576 tokens	262,144 tokens
Maximum output	393,216 tokens	98,304 tokens
Reasoning mode	Yes	Yes
Tool calling	Yes	Yes
Accepted inputs	text, image	text, image, video
Open weights	Yes	Yes
Knowledge cutoff	May 2025	January 2025

What are we comparing?

DeepSeek V4.1 Flash 1017 and Kimi K2.5 are two open-weight models that you can install on your own servers, one from DeepSeek, the other from Moonshot AI. DeepSeek V4.1 Flash 1017 was released on October 17, 2026, Kimi K2.5 on January 27, 2026.

All figures below come from public sources checked on October 22, 2026: models.dev and OpenRouter for prices and capabilities, Epoch AI for scores.

What the benchmarks say

On our capability index, DeepSeek V4.1 Flash 1017 scores 90.6 out of 100 and Kimi K2.5 78.1. DeepSeek V4.1 Flash 1017 leads by 12.5 points.

On the 2 benchmarks reported for both, DeepSeek V4.1 Flash 1017 wins 2 times and Kimi K2.5 0:

GPQA Diamond (PhD-level science questions): DeepSeek V4.1 Flash 1017 93.2%, Kimi K2.5 87.6%
OTIS Mock AIME (competition mathematics problems): DeepSeek V4.1 Flash 1017 99.4%, Kimi K2.5 92.2%

Pricing

DeepSeek V4.1 Flash 1017 costs $0.15 per million input tokens and $0.60 per million output tokens; Kimi K2.5 costs $0.58 and $3.

For a typical agent task (read 20,000 tokens, write 2,000), expect $0.004 with DeepSeek V4.1 Flash 1017 versus $0.018 with Kimi K2.5. DeepSeek V4.1 Flash 1017 is 4.2 times cheaper, a gap that adds up quickly over 1,000 tasks: $13.4 difference.

Run the numbers with your own volumes in the agent cost calculator.

Features and limits

DeepSeek V4.1 Flash 1017 reads more in one go: 1,048,576 tokens of context (roughly 1,573 pages), versus 262,144 for Kimi K2.5.

Reasoning mode: DeepSeek V4.1 Flash 1017 yes, Kimi K2.5 yes. Tool calling: DeepSeek V4.1 Flash 1017 yes, Kimi K2.5 yes. Image input: DeepSeek V4.1 Flash 1017 yes, Kimi K2.5 yes.

Both publish their weights: you can host them yourself.

Knowledge cutoff: May 2025 for DeepSeek V4.1 Flash 1017, January 2025 for Kimi K2.5.

In short

Our reading of the data:

Choose DeepSeek V4.1 Flash 1017 for a higher capability index, a lower cost, a larger context window and a more recent release.

This verdict relies on public figures; it does not replace a trial on your own tasks.

Frequently asked questions

DeepSeek V4.1 Flash 1017 or Kimi K2.5: which is better?

On our index (Epoch AI data), DeepSeek V4.1 Flash 1017 scores 90.6 and Kimi K2.5 78.1 out of 100. The best choice also depends on price and on your use case.

Which one is cheaper?

DeepSeek V4.1 Flash 1017. To read 20,000 tokens and write 2,000, expect $0.004 with DeepSeek V4.1 Flash 1017 and $0.018 with Kimi K2.5 (prices as of October 22, 2026).

Which one has the larger context window?

DeepSeek V4.1 Flash 1017, with 1,048,576 tokens versus 262,144.

Can I run DeepSeek V4.1 Flash 1017 or Kimi K2.5 on my own servers?

Yes, both publish their weights. Check each license before commercial use.

DeepSeek V4.1 Flash 1017 versus Kimi K2.5