Pick Fugu Ultra v2.0 for sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark or claims to outperform flagship models like gpt-6 astra and claude fable 5.1 despite its underlying orchestration pool reportedly excluding both of them. Pick Gemini 2.5 Flash for cheapest 1m-context option or very fast. On a tight budget at scale, Gemini 2.5 Flash is the value pick.
Fugu Ultra v2.0 (Sakana AI) and Gemini 2.5 Flash (Google) are two of the models people most often weigh against each other in 2026. Fugu Ultra v2.0 is sakana AI's flagship multi-agent orchestration model, claiming best-or-joint-best results on 5 of 8 self-reported benchmarks against monolithic frontier models — $5/$30 per million tokens. Gemini 2.5 Flash is google's ultra-cheap, fast 1M-context model for high-volume multimodal work. Their biggest split is price, and the breakdown below shows exactly how that plays out for your workload.
Key differences
Price: Gemini 2.5 Flash is about 17× cheaper on input ($0.3/$2.5 per 1M tokens vs $5/$30 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
Context window: both advertise 1M tokens (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
Recency: Fugu Ultra v2.0 is the newer model by about 16 months (released September 10, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
Fugu Ultra v2.0
Gemini 2.5 Flash
Provider
Sakana AI (Global)
Google (US)
Released
September 10, 2026
June 2025
Context window
1M tokens (~1,500 pages)
1M (~1,500 pages)
Price (in/out)
$5/$30 per 1M tokens
$0.3/$2.5 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text
text, image, audio, video, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the DeepSWE coding-repair benchmark: Fugu Ultra v2.0 — Sakana AI's flagship multi-agent orchestration model, claiming best-or-joint-best results on 5 of 8 self-reported benchmarks against monolithic frontier models — $5/$30 per million tokens — and it is the newer of the two.
Claims to outperform flagship models like GPT-6 Astra and Claude Fable 5.1 despite its underlying orchestration pool reportedly excluding both of them: Fugu Ultra v2.0 — Fugu Ultra v2.0 lists claims to outperform flagship models like GPT-6 Astra and Claude Fable 5.1 despite its underlying orchestration pool reportedly excluding both of them among its strengths; Gemini 2.5 Flash does not.
1M-token context window: Fugu Ultra v2.0 — Fugu Ultra v2.0 lists 1M-token context window among its strengths; Gemini 2.5 Flash does not.
Cheapest 1M-context option: Gemini 2.5 Flash — At $0.3/$2.5 per 1M tokens it undercuts Fugu Ultra v2.0 ($5/$30 per 1M tokens), and that gap compounds at volume.
Very fast: Gemini 2.5 Flash — Google's ultra-cheap, fast 1M-context model for high-volume multimodal work — and it runs cheaper at $0.3/$2.5 per 1M tokens.
High-volume multimodal: Gemini 2.5 Flash — Gemini 2.5 Flash lists high-volume multimodal among its strengths; Fugu Ultra v2.0 does not.
Lowest cost at scale: Gemini 2.5 Flash — At $0.3/$2.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume: Gemini 2.5 Flash — At $0.3/$2.5 per 1M tokens it undercuts Fugu Ultra v2.0, and on millions of tokens that margin decides the monthly bill.
Anyone whose priority is sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark: Fugu Ultra v2.0 — It is specifically built for that.
Anyone whose priority is cheapest 1m-context option: Gemini 2.5 Flash — That is its strongest area.
Fugu Ultra v2.0: where it fits
Sakana AI's flagship multi-agent orchestration model, claiming best-or-joint-best results on 5 of 8 self-reported benchmarks against monolithic frontier models — $5/$30 per million tokens. Released September 10, 2026 by Sakana AI, it is built for sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the DeepSWE coding-repair benchmark, claims to outperform flagship models like GPT-6 Astra and Claude Fable 5.1 despite its underlying orchestration pool reportedly excluding both of them, and 1M-token context window.
Its trade-offs are real: not a single trained model — Sakana describes Fugu as "a Multi-Agent System, Delivered as One Model" that dynamically routes tasks across a pool of other models, so head-to-head benchmark framing against monolithic frontier models should be read skeptically, pricing rises to roughly $10/$45 per million tokens for prompts above 272K tokens, and benchmark comparisons against GPT-6 Astra and Claude Fable 5.1 are Sakana's own self-reported figures, not independently verified head-to-head scores. At $5 in / $30 out per million tokens, it sits in the premium price band.
Gemini 2.5 Flash: where it fits
Google's ultra-cheap, fast 1M-context model for high-volume multimodal work. Released June 2025 by Google, it is built for cheapest 1M-context option, very fast, high-volume multimodal, and workspace integration.
Its trade-offs: lighter reasoning than Pro tiers, and superseded by 3.5 Flash. At $0.3 in / $2.5 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Fugu Ultra v2.0 and Gemini 2.5 Flash overlap enough that the right pick depends on your specific job. Gemini 2.5 Flash costs less per token; and each leads in its own area — Fugu Ultra v2.0 for sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark, Gemini 2.5 Flash for cheapest 1m-context option. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is Fugu Ultra v2.0 or Gemini 2.5 Flash 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 Ultra v2.0 leans toward sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark while Gemini 2.5 Flash leans toward cheapest 1m-context option, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Fugu Ultra v2.0 or Gemini 2.5 Flash?
Gemini 2.5 Flash is cheaper — $5/$30 per 1M tokens vs $0.3/$2.5 per 1M tokens, roughly 17× apart on input.
Which has the bigger context window?
Both advertise 1M tokens (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Fugu Ultra v2.0 and Gemini 2.5 Flash together?
Yes — a multi-model platform like LumiChats gives you Fugu Ultra v2.0, Gemini 2.5 Flash 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 Ultra v2.0 or Gemini 2.5 Flash?
Fugu Ultra v2.0 — released September 10, 2026, about 16 months after Gemini 2.5 Flash.
Fugu Ultra v2.0 vs Gemini 2.5 Flash
Sakana AI · Global | Google · US · Updated June 2026
Quick verdict
Pick Fugu Ultra v2.0 for sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark or claims to outperform flagship models like gpt-6 astra and claude fable 5.1 despite its underlying orchestration pool reportedly excluding both of them. Pick Gemini 2.5 Flash for cheapest 1m-context option or very fast. On a tight budget at scale, Gemini 2.5 Flash is the value pick.
Fugu Ultra v2.0 (Sakana AI) and Gemini 2.5 Flash (Google) are two of the models people most often weigh against each other in 2026. Fugu Ultra v2.0 is sakana AI's flagship multi-agent orchestration model, claiming best-or-joint-best results on 5 of 8 self-reported benchmarks against monolithic frontier models — $5/$30 per million tokens. Gemini 2.5 Flash is google's ultra-cheap, fast 1M-context model for high-volume multimodal work. Their biggest split is price, and the breakdown below shows exactly how that plays out for your workload.
Key differences at a glance
▸Price: Gemini 2.5 Flash is about 17× cheaper on input ($0.3/$2.5 per 1M tokens vs $5/$30 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
▸Context window: both advertise 1M tokens (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
▸Recency: Fugu Ultra v2.0 is the newer model by about 16 months (released September 10, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
Fugu Ultra v2.0
Gemini 2.5 Flash
Provider
Sakana AI (Global)
Google (US)
Released
September 10, 2026
June 2025
Context window
1M tokens (~1,500 pages)
1M (~1,500 pages)
Price (in/out)
$5/$30 per 1M tokens
$0.3/$2.5 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text
text, image, audio, video, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the DeepSWE coding-repair benchmark
Fugu Ultra v2.0
Sakana AI's flagship multi-agent orchestration model, claiming best-or-joint-best results on 5 of 8 self-reported benchmarks against monolithic frontier models — $5/$30 per million tokens — and it is the newer of the two.
Claims to outperform flagship models like GPT-6 Astra and Claude Fable 5.1 despite its underlying orchestration pool reportedly excluding both of them
Fugu Ultra v2.0
Fugu Ultra v2.0 lists claims to outperform flagship models like GPT-6 Astra and Claude Fable 5.1 despite its underlying orchestration pool reportedly excluding both of them among its strengths; Gemini 2.5 Flash does not.
1M-token context window
Fugu Ultra v2.0
Fugu Ultra v2.0 lists 1M-token context window among its strengths; Gemini 2.5 Flash does not.
Cheapest 1M-context option
Gemini 2.5 Flash
At $0.3/$2.5 per 1M tokens it undercuts Fugu Ultra v2.0 ($5/$30 per 1M tokens), and that gap compounds at volume.
Very fast
Gemini 2.5 Flash
Google's ultra-cheap, fast 1M-context model for high-volume multimodal work — and it runs cheaper at $0.3/$2.5 per 1M tokens.
High-volume multimodal
Gemini 2.5 Flash
Gemini 2.5 Flash lists high-volume multimodal among its strengths; Fugu Ultra v2.0 does not.
Lowest cost at scale
Gemini 2.5 Flash
At $0.3/$2.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Gemini 2.5 Flash
At $0.3/$2.5 per 1M tokens it undercuts Fugu Ultra v2.0, and on millions of tokens that margin decides the monthly bill.
Anyone whose priority is sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark
→ Fugu Ultra v2.0
It is specifically built for that.
Anyone whose priority is cheapest 1m-context option
→ Gemini 2.5 Flash
That is its strongest area.
Fugu Ultra v2.0: where it fits
Sakana AI's flagship multi-agent orchestration model, claiming best-or-joint-best results on 5 of 8 self-reported benchmarks against monolithic frontier models — $5/$30 per million tokens. Released September 10, 2026 by Sakana AI, it is built for sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the DeepSWE coding-repair benchmark, claims to outperform flagship models like GPT-6 Astra and Claude Fable 5.1 despite its underlying orchestration pool reportedly excluding both of them, and 1M-token context window.
Its trade-offs are real: not a single trained model — Sakana describes Fugu as "a Multi-Agent System, Delivered as One Model" that dynamically routes tasks across a pool of other models, so head-to-head benchmark framing against monolithic frontier models should be read skeptically, pricing rises to roughly $10/$45 per million tokens for prompts above 272K tokens, and benchmark comparisons against GPT-6 Astra and Claude Fable 5.1 are Sakana's own self-reported figures, not independently verified head-to-head scores. At $5 in / $30 out per million tokens, it sits in the premium price band.
Gemini 2.5 Flash: where it fits
Google's ultra-cheap, fast 1M-context model for high-volume multimodal work. Released June 2025 by Google, it is built for cheapest 1M-context option, very fast, high-volume multimodal, and workspace integration.
Its trade-offs: lighter reasoning than Pro tiers, and superseded by 3.5 Flash. At $0.3 in / $2.5 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Fugu Ultra v2.0 and Gemini 2.5 Flash overlap enough that the right pick depends on your specific job. Gemini 2.5 Flash costs less per token; and each leads in its own area — Fugu Ultra v2.0 for sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark, Gemini 2.5 Flash for cheapest 1m-context option. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Fugu Ultra v2.0 and Gemini 2.5 Flash 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.
Is Fugu Ultra v2.0 or Gemini 2.5 Flash 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 Ultra v2.0 leans toward sakana's own evaluation reports best-or-joint-best results on 5 of 8 benchmarks tested, including a 74.3 on the deepswe coding-repair benchmark while Gemini 2.5 Flash leans toward cheapest 1m-context option, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Fugu Ultra v2.0 or Gemini 2.5 Flash?
Gemini 2.5 Flash is cheaper — $5/$30 per 1M tokens vs $0.3/$2.5 per 1M tokens, roughly 17× apart on input.
Which has the bigger context window?
Both advertise 1M tokens (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Fugu Ultra v2.0 and Gemini 2.5 Flash together?
Yes — a multi-model platform like LumiChats gives you Fugu Ultra v2.0, Gemini 2.5 Flash 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 Ultra v2.0 or Gemini 2.5 Flash?
Fugu Ultra v2.0 — released September 10, 2026, about 16 months after Gemini 2.5 Flash.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.