AI Models · Open-Source vs Paid

Kimi K3.1 Pro Open vs SAFugu Ultra Paid

Kimi K3.1 Pro vs Fugu Ultra compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

Kimi K3.1 ProOpenMoonshot AI
$2 /M input
$10 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window1M tokens
MultimodalYes
Self-hostYes
SAFugu UltraPaidSakana AI
$5 /M input
$30 /M outputManaged API (no infra to run)
TypeProprietary
Context window1M tokens
MultimodalYes
Self-hostNo
Choose Kimi K3.1 Pro if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Fugu Ultra if you want frontier capability through a managed API with zero infrastructure to run.

Kimi K3.1 Pro vs Fugu Ultra specs

SpecKimi K3.1 ProFugu UltraWinner
MakerMoonshot AISakana AI–
TypeOpen-weightProprietaryKimi K3.1 Pro
Context window1M tokens1M tokensKimi K3.1 Pro
Input price$2/M · free self-host$5/MKimi K3.1 Pro
Output price$10/M · free self-host$30/MKimi K3.1 Pro
Vision / multimodalYesYes= Tie
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)Kimi K3.1 Pro
LicenseModified MITProprietaryKimi K3.1 Pro

Price gap & when to choose each

3.0×cheaper per output token

Kimi K3.1 Pro is ~3.0× cheaper than Fugu Ultra on output tokens ($10 vs $30 per M tokens).

Choose Kimi K3.1 Pro if…
  • You want to self-host or run on your cloud
  • You need the longer 1M context window
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
SAChoose Fugu Ultra if…
  • You want frontier performance through a managed API
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityKimi K3.1 ProFugu Ultra
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✓✓

Benchmarks: Kimi K3.1 Pro vs Fugu Ultra

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Kimi K3.1 Pro
Fugu Ultra
Intelligence index
55.1
–
Humanity's Last Exam
52.5%
–
Long Context Reasoning
86.3%
–
SciCode
60.8%
–
Speed
41.2 tok/s
–
Latency
2.12s
–
Intelligence per $
13.8
–

Benchmark data by Artificial Analysis.

How Kimi K3.1 Pro and Fugu Ultra score

🏆 Best value & openness: Kimi K3.1 Pro (4.7 vs 3.1 / 5)
CriterionKimi K3.1 ProFugu Ultra
Cost-efficiency3.53.0
Context window5.05.0
Openness5.01.5
Self-hosting5.01.0
Multimodality5.05.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

Kimi K3.1 Pro Open

Moonshot AI · Open-weight

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...

Fugu Ultra Paid

Sakana AI · Proprietary

Fugu Ultra is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to route...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Kimi K3Kimi K3 (batch)Kimi K2.6Kimi K2.7 CodeKimi K2.5Kimi K2 ThinkingKimi K2 0905Kimi K2 0711

Frequently asked questions

Is Kimi K3.1 Pro as good as Fugu Ultra?

Kimi K3.1 Pro is open-weight and competitive on many tasks, but Fugu Ultra may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run Kimi K3.1 Pro locally?

Yes. Kimi K3.1 Pro has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Fugu Ultra is API-only and cannot be self-hosted.

How much cheaper is Kimi K3.1 Pro?

Kimi K3.1 Pro costs $10/M output vs $30/M for Fugu Ultra — roughly 3x cheaper via API, and free if you self-host.

Kimi K3.1 Pro vs Fugu Ultra — which should I pick in 2026?

Choose Kimi K3.1 Pro if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Fugu Ultra if you want frontier capability through a managed API with zero infrastructure to run.

People also compare

Explore more open-source AI

Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.

Open the leaderboard →