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. Pick GPT-5.1 for adaptive reasoning that scales compute to task difficulty or general-purpose reasoning, coding and tool use. On a tight budget at scale, GPT-5.1 is the value pick.
Fugu Max (Sakana AI) and GPT-5.1 (OpenAI) are two of the models people most often weigh against each other in 2026. 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. GPT-5.1 is openAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences
Price: GPT-5.1 is about 1.6× cheaper on input ($1.25/$10 per 1M tokens vs $2/$6 per 1M tokens) — modest, but it adds up at steady volume.
Context window: Fugu Max holds 2.5× more — 1M tokens (~1,500 pages) vs 400K (~600 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Recency: Fugu Max is the newer model by about 10 months (released September 10, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
Fugu Max
GPT-5.1
Provider
Sakana AI (Global)
OpenAI (US)
Released
September 10, 2026
November 13, 2025
Context window
1M tokens (~1,500 pages)
400K (~600 pages)
Price (in/out)
$2/$6 per 1M tokens
$1.25/$10 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text
text, image, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Cost-efficient multi-agent orchestration — undercuts Claude Sonnet 5 and Kimi K3 on output cost by a claimed 40-60%: Fugu Max — GPT-5.1 is comparatively weak here — premium output price at $10/1M for a now-older model
1M-token context window at $2/$6 per million tokens: Fugu Max — Its 1M tokens window holds about 2.5× more than GPT-5.1's 400K in a single prompt.
OpenAI-compatible API — drop-in replacement for single-model integrations: 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 carries the larger 1M tokens context.
Adaptive reasoning that scales compute to task difficulty: GPT-5.1 — At $1.25/$10 per 1M tokens it undercuts Fugu Max ($2/$6 per 1M tokens), and that gap compounds at volume.
General-purpose reasoning, coding and tool use: GPT-5.1 — Fugu Max is comparatively weak here — the cheaper sibling to Fugu Ultra v2 — lower ceiling on the hardest reasoning tasks
A large ~400K context for long documents and sessions: GPT-5.1 — OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line — and it runs cheaper at $1.25/$10 per 1M tokens.
Lowest cost at scale: GPT-5.1 — At $1.25/$10 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input: Fugu Max — Its 1M tokens window is about 2.5× larger than GPT-5.1's 400K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: GPT-5.1 — At $1.25/$10 per 1M tokens it undercuts Fugu Max, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: Fugu Max — Larger 1M tokens window fits more in one prompt.
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 — It is specifically built for that.
Anyone whose priority is adaptive reasoning that scales compute to task difficulty: GPT-5.1 — That is its strongest area.
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 are real: 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.
GPT-5.1: where it fits
OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. Released November 13, 2025 by OpenAI, it is built for adaptive reasoning that scales compute to task difficulty, general-purpose reasoning, coding and tool use, a large ~400K context for long documents and sessions, and text and image input.
Its trade-offs: superseded by GPT-5.2 through GPT-5.6 — kept for compatibility rather than being current, no reliably published SWE-Bench Verified figure, exact context window unconfirmed (400K vs 410K across trackers), and premium output price at $10/1M for a now-older model. At $1.25 in / $10 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Fugu Max and GPT-5.1 overlap enough that the right pick depends on your specific job. GPT-5.1 costs less per token; Fugu Max holds the larger context; and each leads in its own area — Fugu Max for cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%, GPT-5.1 for adaptive reasoning that scales compute to task difficulty. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is Fugu Max or GPT-5.1 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, Fugu Max leans toward cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60% while GPT-5.1 leans toward adaptive reasoning that scales compute to task difficulty, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Fugu Max or GPT-5.1?
GPT-5.1 is cheaper — $2/$6 per 1M tokens vs $1.25/$10 per 1M tokens, roughly 1.6× apart on input.
Which has the bigger context window?
Fugu Max — 1M tokens vs 400K, about 2.5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Fugu Max and GPT-5.1 together?
Yes — a multi-model platform like LumiChats gives you Fugu Max, GPT-5.1 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, Fugu Max or GPT-5.1?
Fugu Max — released September 10, 2026, about 10 months after GPT-5.1.
Fugu Max vs GPT-5.1
Sakana AI · Global | OpenAI · US · Updated June 2026
Quick verdict
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. Pick GPT-5.1 for adaptive reasoning that scales compute to task difficulty or general-purpose reasoning, coding and tool use. On a tight budget at scale, GPT-5.1 is the value pick.
Fugu Max (Sakana AI) and GPT-5.1 (OpenAI) are two of the models people most often weigh against each other in 2026. 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. GPT-5.1 is openAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
▸Price: GPT-5.1 is about 1.6× cheaper on input ($1.25/$10 per 1M tokens vs $2/$6 per 1M tokens) — modest, but it adds up at steady volume.
▸Context window: Fugu Max holds 2.5× more — 1M tokens (~1,500 pages) vs 400K (~600 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
▸Recency: Fugu Max is the newer model by about 10 months (released September 10, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
Fugu Max
GPT-5.1
Provider
Sakana AI (Global)
OpenAI (US)
Released
September 10, 2026
November 13, 2025
Context window
1M tokens (~1,500 pages)
400K (~600 pages)
Price (in/out)
$2/$6 per 1M tokens
$1.25/$10 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text
text, image, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Cost-efficient multi-agent orchestration — undercuts Claude Sonnet 5 and Kimi K3 on output cost by a claimed 40-60%
Fugu Max
GPT-5.1 is comparatively weak here — premium output price at $10/1M for a now-older model
1M-token context window at $2/$6 per million tokens
Fugu Max
Its 1M tokens window holds about 2.5× more than GPT-5.1's 400K in a single prompt.
OpenAI-compatible API — drop-in replacement for single-model integrations
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 carries the larger 1M tokens context.
Adaptive reasoning that scales compute to task difficulty
GPT-5.1
At $1.25/$10 per 1M tokens it undercuts Fugu Max ($2/$6 per 1M tokens), and that gap compounds at volume.
General-purpose reasoning, coding and tool use
GPT-5.1
Fugu Max is comparatively weak here — the cheaper sibling to Fugu Ultra v2 — lower ceiling on the hardest reasoning tasks
A large ~400K context for long documents and sessions
GPT-5.1
OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line — and it runs cheaper at $1.25/$10 per 1M tokens.
Lowest cost at scale
GPT-5.1
At $1.25/$10 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input
Fugu Max
Its 1M tokens window is about 2.5× larger than GPT-5.1's 400K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ GPT-5.1
At $1.25/$10 per 1M tokens it undercuts Fugu Max, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Fugu Max
Larger 1M tokens window fits more in one prompt.
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
It is specifically built for that.
Anyone whose priority is adaptive reasoning that scales compute to task difficulty
→ GPT-5.1
That is its strongest area.
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 are real: 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.
GPT-5.1: where it fits
OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. Released November 13, 2025 by OpenAI, it is built for adaptive reasoning that scales compute to task difficulty, general-purpose reasoning, coding and tool use, a large ~400K context for long documents and sessions, and text and image input.
Its trade-offs: superseded by GPT-5.2 through GPT-5.6 — kept for compatibility rather than being current, no reliably published SWE-Bench Verified figure, exact context window unconfirmed (400K vs 410K across trackers), and premium output price at $10/1M for a now-older model. At $1.25 in / $10 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Fugu Max and GPT-5.1 overlap enough that the right pick depends on your specific job. GPT-5.1 costs less per token; Fugu Max holds the larger context; and each leads in its own area — Fugu Max for cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60%, GPT-5.1 for adaptive reasoning that scales compute to task difficulty. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Fugu Max and GPT-5.1 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, Fugu Max leans toward cost-efficient multi-agent orchestration — undercuts claude sonnet 5 and kimi k3 on output cost by a claimed 40-60% while GPT-5.1 leans toward adaptive reasoning that scales compute to task difficulty, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Fugu Max or GPT-5.1?
GPT-5.1 is cheaper — $2/$6 per 1M tokens vs $1.25/$10 per 1M tokens, roughly 1.6× apart on input.
Which has the bigger context window?
Fugu Max — 1M tokens vs 400K, about 2.5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Fugu Max and GPT-5.1 together?
Yes — a multi-model platform like LumiChats gives you Fugu Max, GPT-5.1 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, Fugu Max or GPT-5.1?
Fugu Max — released September 10, 2026, about 10 months after GPT-5.1.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.