Pick Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously or multi-step coding, debugging, and tool use. Pick Fugu Max for cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60% or 1m-token context window at $2/$6 per million tokens.
Claude Sonnet 5 (Anthropic) and Fugu Max (Sakana AI) are two of the models people most often weigh against each other in 2026. Claude Sonnet 5 is anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Fugu Max is sakana AI's cost-first multi-agent orchestration model — not a single trained model, but a routed pool of models behind one API, priced at $2/$6 per million tokens. The breakdown below works through their capabilities and ideal use cases so you can match one to your task.
Key differences
Context window: both advertise 1M (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
Recency: Fugu Max is the newer model by about 2 months (released September 10, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
Claude Sonnet 5
Fugu Max
Provider
Anthropic (US)
Sakana AI (Global)
Released
June 30, 2026
September 10, 2026
Context window
1M (~1,500 pages)
1M tokens (~1,500 pages)
Price (in/out)
$2/$10 per 1M tokens
$2/$6 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Agentic workflows that plan, use tools, and run autonomously: Claude Sonnet 5 — Claude Sonnet 5 lists agentic workflows that plan, use tools, and run autonomously among its strengths; Fugu Max does not.
Multi-step coding, debugging, and tool use: Claude Sonnet 5 — Fugu Max is comparatively weak here — not a single trained model — Sakana describes Fugu as "a Multi-Agent System, Delivered as One Model" that routes tasks across a pool of other models, so raw benchmark comparisons to monolithic models can be misleading
Everyday professional and knowledge work: Claude Sonnet 5 — Claude Sonnet 5 lists everyday professional and knowledge work among its strengths; Fugu Max does not.
Cost-efficient multi-agent orchestration — undercuts Claude Sonnet 5 and Kimi K3 on output cost by a claimed 40-60%: Fugu Max — Sakana AI's cost-first multi-agent orchestration model — not a single trained model, but a routed pool of models behind one API, priced at $2/$6 per million tokens — and it is the newer of the two.
1M-token context window at $2/$6 per million tokens: Fugu Max — Claude Sonnet 5 is comparatively weak here — an updated tokenizer that can use 1.0-1.35x more tokens for the same text
OpenAI-compatible API — drop-in replacement for single-model integrations: Fugu Max — Fugu Max lists openAI-compatible API — drop-in replacement for single-model integrations among its strengths; Claude Sonnet 5 does not.
Which should you pick?
Anyone whose priority is agentic workflows that plan, use tools, and run autonomously: Claude Sonnet 5 — It is specifically built for that.
Anyone whose priority is cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%: Fugu Max — That is its strongest area.
Claude Sonnet 5: where it fits
Anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Released June 30, 2026 by Anthropic, it is built for agentic workflows that plan, use tools, and run autonomously, multi-step coding, debugging, and tool use, everyday professional and knowledge work, and long-document analysis and reasoning.
Its trade-offs are real: lower peak accuracy than Opus 4.8 on the hardest tasks, and an updated tokenizer that can use 1.0-1.35x more tokens for the same text. At $2 in / $10 out per million tokens, it sits in the mid price band.
Fugu Max: where it fits
Sakana AI's cost-first multi-agent orchestration model — not a single trained model, but a routed pool of models behind one API, priced at $2/$6 per million tokens. Released September 10, 2026 by Sakana AI, it is built for cost-efficient multi-agent orchestration — undercuts Claude Sonnet 5 and Kimi K3 on output cost by a claimed 40-60%, 1M-token context window at $2/$6 per million tokens, and openAI-compatible API — drop-in replacement for single-model integrations.
Its trade-offs: not a single trained model — Sakana describes Fugu as "a Multi-Agent System, Delivered as One Model" that routes tasks across a pool of other models, so raw benchmark comparisons to monolithic models can be misleading, the cheaper sibling to Fugu Ultra v2 — lower ceiling on the hardest reasoning tasks, and a young, first-generation product from Sakana AI's orchestration approach, unproven at scale versus established frontier labs. At $2 in / $6 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Claude Sonnet 5 and Fugu Max overlap enough that the right pick depends on your specific job. and each leads in its own area — Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously, Fugu Max for cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is Claude Sonnet 5 or Fugu Max better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 5 leans toward agentic workflows that plan, use tools, and run autonomously while Fugu Max leans toward cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Sonnet 5 or Fugu Max?
They are priced almost identically, so cost will not decide between them.
Which has the bigger context window?
Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Claude Sonnet 5 and Fugu Max together?
Yes — a multi-model platform like LumiChats gives you Claude Sonnet 5, Fugu Max and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Claude Sonnet 5 or Fugu Max?
Fugu Max — released September 10, 2026, about 2 months after Claude Sonnet 5.
Claude Sonnet 5 vs Fugu Max
Anthropic · US | Sakana AI · Global · Updated June 2026
Quick verdict
Pick Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously or multi-step coding, debugging, and tool use. Pick Fugu Max for cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60% or 1m-token context window at $2/$6 per million tokens.
Claude Sonnet 5 (Anthropic) and Fugu Max (Sakana AI) are two of the models people most often weigh against each other in 2026. Claude Sonnet 5 is anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Fugu Max is sakana AI's cost-first multi-agent orchestration model — not a single trained model, but a routed pool of models behind one API, priced at $2/$6 per million tokens. The breakdown below works through their capabilities and ideal use cases so you can match one to your task.
Key differences at a glance
▸Context window: both advertise 1M (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
▸Recency: Fugu Max is the newer model by about 2 months (released September 10, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
Claude Sonnet 5
Fugu Max
Provider
Anthropic (US)
Sakana AI (Global)
Released
June 30, 2026
September 10, 2026
Context window
1M (~1,500 pages)
1M tokens (~1,500 pages)
Price (in/out)
$2/$10 per 1M tokens
$2/$6 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Agentic workflows that plan, use tools, and run autonomously
Claude Sonnet 5
Claude Sonnet 5 lists agentic workflows that plan, use tools, and run autonomously among its strengths; Fugu Max does not.
Multi-step coding, debugging, and tool use
Claude Sonnet 5
Fugu Max is comparatively weak here — not a single trained model — Sakana describes Fugu as "a Multi-Agent System, Delivered as One Model" that routes tasks across a pool of other models, so raw benchmark comparisons to monolithic models can be misleading
Everyday professional and knowledge work
Claude Sonnet 5
Claude Sonnet 5 lists everyday professional and knowledge work among its strengths; Fugu Max does not.
Cost-efficient multi-agent orchestration — undercuts Claude Sonnet 5 and Kimi K3 on output cost by a claimed 40-60%
Fugu Max
Sakana AI's cost-first multi-agent orchestration model — not a single trained model, but a routed pool of models behind one API, priced at $2/$6 per million tokens — and it is the newer of the two.
1M-token context window at $2/$6 per million tokens
Fugu Max
Claude Sonnet 5 is comparatively weak here — an updated tokenizer that can use 1.0-1.35x more tokens for the same text
OpenAI-compatible API — drop-in replacement for single-model integrations
Fugu Max
Fugu Max lists openAI-compatible API — drop-in replacement for single-model integrations among its strengths; Claude Sonnet 5 does not.
Which should you pick?
Anyone whose priority is agentic workflows that plan, use tools, and run autonomously
→ Claude Sonnet 5
It is specifically built for that.
Anyone whose priority is cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%
→ Fugu Max
That is its strongest area.
Claude Sonnet 5: where it fits
Anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Released June 30, 2026 by Anthropic, it is built for agentic workflows that plan, use tools, and run autonomously, multi-step coding, debugging, and tool use, everyday professional and knowledge work, and long-document analysis and reasoning.
Its trade-offs are real: lower peak accuracy than Opus 4.8 on the hardest tasks, and an updated tokenizer that can use 1.0-1.35x more tokens for the same text. At $2 in / $10 out per million tokens, it sits in the mid price band.
Fugu Max: where it fits
Sakana AI's cost-first multi-agent orchestration model — not a single trained model, but a routed pool of models behind one API, priced at $2/$6 per million tokens. Released September 10, 2026 by Sakana AI, it is built for cost-efficient multi-agent orchestration — undercuts Claude Sonnet 5 and Kimi K3 on output cost by a claimed 40-60%, 1M-token context window at $2/$6 per million tokens, and openAI-compatible API — drop-in replacement for single-model integrations.
Its trade-offs: not a single trained model — Sakana describes Fugu as "a Multi-Agent System, Delivered as One Model" that routes tasks across a pool of other models, so raw benchmark comparisons to monolithic models can be misleading, the cheaper sibling to Fugu Ultra v2 — lower ceiling on the hardest reasoning tasks, and a young, first-generation product from Sakana AI's orchestration approach, unproven at scale versus established frontier labs. At $2 in / $6 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Claude Sonnet 5 and Fugu Max overlap enough that the right pick depends on your specific job. and each leads in its own area — Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously, Fugu Max for cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Claude Sonnet 5 and Fugu Max without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 5 leans toward agentic workflows that plan, use tools, and run autonomously while Fugu Max leans toward cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Sonnet 5 or Fugu Max?
They are priced almost identically, so cost will not decide between them.
Which has the bigger context window?
Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Claude Sonnet 5 and Fugu Max together?
Yes — a multi-model platform like LumiChats gives you Claude Sonnet 5, Fugu Max and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Claude Sonnet 5 or Fugu Max?
Fugu Max — released September 10, 2026, about 2 months after Claude Sonnet 5.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.