Grok 4.5 vs Fugu Ultra v2
Detailed technical comparison between Grok 4.5 (xAI) and Fugu Ultra v2 (Sakana AI). Review live API token pricing, context window capabilities, time-to-first-token latency, and verified benchmark scores side-by-side.
Comparison Snapshot
Fugu Ultra v2
1,000,000 tokensTie
Equal CapabilityTie
Equal SpeedGrok 4.5
$2.00 / MTokGrok 4.5
Grok 4.5 is an advanced artificial intelligence model engineered by xAI. Tailored for complex multi-step reasoning, programming synthesis, and extended document comprehension, Grok 4.5 represents a key architectural iteration in the xAI model family. First released in 2026-07-08, it serves enterprise developers, research teams, and autonomous system architects requiring strict instruction compliance. Featuring an input capacity of 500,000 tokens (approximately 667 words), Grok 4.5 processes multi-file code repositories, lengthy technical reports, and complex prompts in a single inference call.
Fugu Ultra v2
Fugu Ultra v2 is an advanced artificial intelligence model engineered by Sakana AI. Tailored for complex multi-step reasoning, programming synthesis, and extended document comprehension, Fugu Ultra v2 represents a key architectural iteration in the Sakana AI model family. First released in 2026-09-11, it serves enterprise developers, research teams, and autonomous system architects requiring strict instruction compliance. Featuring an input capacity of 1,000,000 tokens (approximately 1,333 words), Fugu Ultra v2 processes multi-file code repositories, lengthy technical reports, and complex prompts in a single inference call.
Technical Specifications
🏆 = Superior Spec| Specification | Grok 4.5 | Fugu Ultra v2 |
|---|---|---|
| Provider | xAI | Sakana AI |
| Context Window | 500,000 tokens | 1,000,000 tokens🏆 |
| Agent Suitability | Not yet benchmarked | Not yet benchmarked |
| Time to First Token (TTFT) | No public TTFT data | No public TTFT data |
| Deployment Model | managed api | managed api |
| Production Stability | Stable GA (est.) | Beta Access (est.) |
| API Available | Yes | Yes |
| Released Date | 2026-07-08 | 2026-09-11 |
API Pricing Comparison
Input Price per Million Tokens
Grok 4.5
$2.00
Fugu Ultra v2
$5.00
Output Price per Million Tokens
Grok 4.5
$6.00
Fugu Ultra v2
$30.00
💡 Cost Ratio: Grok 4.5 is 2.5x cheaper per input token than Fugu Ultra v2.
Want to test both models live?
Run side-by-side prompt benchmarks in our dynamic multi-model Sandbox. Compare execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Standardized Scores (0–100%)Scores show verified raw accuracy percentages across standardized AI evaluation suites. Higher bars indicate superior performance in that domain.
Grok 4.5 Quirks & Gotchas
No developer gotchas reported.
Fugu Ultra v2 Quirks & Gotchas
No developer gotchas reported.
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