Fugu Max vs GPT-5.3-Codex

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-5.3-Codex for dedicated coding agent or cli and ide integration. On a tight budget at scale, GPT-5.3-Codex is the value pick.

Fugu Max (Sakana AI) and GPT-5.3-Codex (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-5.3-Codex is openAI's coding-specialized agent model for autonomous software engineering. They diverge most on price and context window — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecFugu MaxGPT-5.3-Codex
ProviderSakana AI (Global) OpenAI (US)
ReleasedSeptember 10, 2026 February 5, 2026
Context window1M tokens (~1,500 pages) 400K (~600 pages)
Price (in/out)$2/$6 per 1M tokens $1.75/$14 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot 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

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.

1M-token context window at $2/$6 per million tokens

Fugu Max

Its 1M tokens window holds about 2.5× more than GPT-5.3-Codex'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 is the newer of the two.

Dedicated coding agent

GPT-5.3-Codex

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

CLI and IDE integration

GPT-5.3-Codex

OpenAI's coding-specialized agent model for autonomous software engineering — and it runs cheaper at $1.75/$14 per 1M tokens.

Autonomous software tasks

GPT-5.3-Codex

GPT-5.3-Codex lists autonomous software tasks among its strengths; Fugu Max does not.

Lowest cost at scale

GPT-5.3-Codex

At $1.75/$14 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-5.3-Codex's 400K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.3-Codex

At $1.75/$14 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 dedicated coding agent

GPT-5.3-Codex

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-5.3-Codex: where it fits

OpenAI's coding-specialized agent model for autonomous software engineering. Released February 5, 2026 by OpenAI, it is built for dedicated coding agent, cLI and IDE integration, autonomous software tasks, and tool calling.

Its trade-offs: coding-specialized, narrower general use, and retired in favor of GPT-5.5 Codex. At $1.75 in / $14 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

Fugu Max and GPT-5.3-Codex overlap enough that the right pick depends on your specific job. GPT-5.3-Codex 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-5.3-Codex for dedicated coding agent. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Fugu Max and GPT-5.3-Codex 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.

See pricing

Frequently asked questions

Is Fugu Max or GPT-5.3-Codex 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-5.3-Codex leans toward dedicated coding agent, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Fugu Max or GPT-5.3-Codex?

GPT-5.3-Codex is cheaper — $2/$6 per 1M tokens vs $1.75/$14 per 1M tokens, roughly 1.1× 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-5.3-Codex together?

Yes — a multi-model platform like LumiChats gives you Fugu Max, GPT-5.3-Codex 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-5.3-Codex?

Fugu Max — released September 10, 2026, about 7 months after GPT-5.3-Codex.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.