Kimi K2.6 (Moonshot) logoOur pick
A
8.1/10

Kimi K2.6 (Moonshot)

VS
StepFun Step 3.5 Flash logo
B
7.8/10

StepFun Step 3.5 Flash

Kimi K2.6 (Moonshot) vs StepFun Step 3.5 Flash

Tier-list head-to-head. Kimi K2.6 (Moonshot) takes the A-tier slot — here's the breakdown.

Last reviewed May 13, 2026· sweep-fresh

Spec sheet

At a glance

 Kimi K2.6 (Moonshot) logoKimi K2.6 (Moonshot)StepFun Step 3.5 Flash logoStepFun Step 3.5 Flash
TierA-tierwinB-tier
Overall score8.1 / 10win7.8 / 10
Free tierYesYes
Starting price$0$0
Best forAgentic coding workflows, tool-use agents, and teams willing to pay hosted-API prices for frontier-tier qua…Teams building agent systems on Chinese open-weight foundations who want something other than DeepSeek or Q…
Last reviewed2026-05-132026-04-17

Head-to-head

Score showdown

Rated 1-10 on the same rubric across all 130 tools we cover.

Ease of useTie
Kimi K2.6 (Moonshot)
6.0
StepFun Step 3.5 Flash
6.0
Output quality+1.0 Kimi K2.6 (Moonshot)
Kimi K2.6 (Moonshot)
9.0
StepFun Step 3.5 Flash
8.0
Value+0.5 StepFun Step 3.5 Flash
Kimi K2.6 (Moonshot)
8.5
StepFun Step 3.5 Flash
9.0
Features+1.0 Kimi K2.6 (Moonshot)
Kimi K2.6 (Moonshot)
9.0
StepFun Step 3.5 Flash
8.0
Overall+0.3 Kimi K2.6 (Moonshot)
Kimi K2.6 (Moonshot)
8.1
StepFun Step 3.5 Flash
7.8

What you'll pay

Pricing snapshot

Look past the headline number -- entry-tier limits drive most cost surprises.

Kimi K2.6 (Moonshot) logo

Kimi K2.6 (Moonshot)

Free tier available

  • Self-hosted (Free)$0
  • API (Moonshot direct, K2.6)$0.60/per 1M input tokens
  • API (OpenRouter, K2.6 blended)~$0.95/per 1M input tokens
StepFun Step 3.5 Flash logo

StepFun Step 3.5 Flash

Free tier available

  • Self-hosted (Apache 2.0)$0
  • API (StepFun / OpenRouter)Usage-based/per 1M tokens

Benchmark Head-to-Head

Kimi K2.6 (1T/32B active MoE) -- Artificial Analysis Intelligence Index v4.0 score 54 (#1 open-weights, #4 overall as of 2026-04-27). MMLU/GPQA/AIME shown below are K2.5-baseline numbers retained until K2.6-specific third-party runs publish benchmarks — StepFun Step 3.5 Flash has no published benchmarks

BenchmarkScore
SWE-Bench Pro58.6%
MMLU-Pro (K2.5 baseline)84.8%
GPQA Diamond (K2.5 baseline)80.5%
AIME 2025 (K2.5 baseline)91.2%
LiveCodeBench (K2.5 baseline)74.1%

The decision

Which should you pick?

Use-case anchors and category strengths, side by side.

Our pick
Kimi K2.6 (Moonshot) logo

Pick Kimi K2.6 (Moonshot)if…

A
8.1/10
  • Higher output quality (9.0 vs 8.0) where polish matters more than speed
  • More feature surface area for power users who'll use the depth
  • Agentic coding workflows, tool-use agents, and teams willing to pay hosted-API prices for frontier-tier quality with open-weights licensing protection.

Agentic coding workflows, tool-use agents, and teams willing to pay hosted-API prices for frontier-tier quality with open-weights licensing protection.

Visit Kimi K2.6 (Moonshot)
StepFun Step 3.5 Flash logo

Pick StepFun Step 3.5 Flashif…

B
7.8/10
  • Teams building agent systems on Chinese open-weight foundations who want something other than DeepSeek or Qwen, especially if agentic tool-use is the primary workload.
  • Also good for Chinese-market products where StepFun's domestic tuning advantages matter.

Teams building agent systems on Chinese open-weight foundations who want something other than DeepSeek or Qwen, especially if agentic tool-use is the primary workload. Also good for Chinese-market products where StepFun's domestic tuning advantages matter. And for anyone looking to add diversity to their open-weight evaluation matrix beyond the top-3 Chinese labs.

Visit StepFun Step 3.5 Flash

Bottom line

The verdict

Kimi K2.6 (Moonshot) (A-tier, 8.1/10) and StepFun Step 3.5 Flash (B-tier, 7.8/10) are within margin-of-error of each other on overall score. There's no decisive winner -- the right pick comes down to how you'll actually use the tool, not which scored higher in the abstract. We rate them on the same rubric (ease of use, output quality, value, features), and on this pair the rubric is calling it a draw.

Pricing-wise, both tools have a free tier (Kimi K2.6 (Moonshot) starts $0, StepFun Step 3.5 Flash starts $0), so you can test either without committing. Compare what each free tier actually unlocks -- usage caps, model access, and feature gates differ a lot more than the headline price suggests, especially as both vendors have tightened limits in 2026.

By use case: pick Kimi K2.6 (Moonshot) when agentic coding workflows, tool-use agents, and teams willing to pay hosted-api prices for frontier-tier quality with open-weights licensing protection. Pick StepFun Step 3.5 Flash when teams building agent systems on chinese open-weight foundations who want something other than deepseek or qwen, especially if agentic tool-use is the primary workload. The two tools aren't fighting for the same person -- they're aiming at adjacent jobs that occasionally overlap. If you're squarely in Kimi K2.6 (Moonshot)'s lane, the tier-list ranking and the use-case fit point the same direction; if you're in StepFun Step 3.5 Flash's lane, the score gap matters less than the fit.

Bottom line: this pair is a coin flip on raw scores. Choose by use-case fit, free-tier availability, and which one you can actually try without committing. Re-evaluate in 60-90 days -- both vendors are shipping fast in 2026.

AIToolTier verdictLast reviewed May 13, 2026Tier rubric · ease of use, output, value, features

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Built from our daily AI-tool sweep, last touched May 13, 2026. Honest tier-list reviews — no affiliate-link pieces disguised as advice. See the rubric or how we review.