Fugu Ultra vs Claude Mythos 5 vs Qwen 3.8 Max Prime
Qwen 3.8 Max Prime comes out ahead, 42 to 36 and 33 on our weighted score, and it is the cheaper option too.
Sakana AI
Fugu Ultra
33/100- ECI—
- Price$5.00 / $30.00
- Context1M
AnthropicClaude Mythos 5
36/100- ECI—
- Price$10.00 / $50.00
- Context1M
- Our pick
Alibaba (Qwen)Qwen 3.8 Max Prime
42/100- ECI—
- Price$4.00 / $12.00
- Context1M
Qwen 3.8 Max Prime is our pick
Qwen 3.8 Max Prime is the better all-round choice, scoring 42/100 against Claude Mythos 5 (36) and Fugu Ultra (33). It leads on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceQwen 3.8 Max PrimeQwen 3.8 Max Prime $6.00 · Fugu Ultra $11.25 · Claude Mythos 5 $20.00 per 1M tokens (3:1 blend)
- Longest contextAbout the sameFugu Ultra 1,000,000 · Claude Mythos 5 1,000,000 · Qwen 3.8 Max Prime 1,000,000 tokens
- Widest inputsClaude Mythos 5 and Qwen 3.8 Max PrimeFugu Ultra: Text, Images · Claude Mythos 5: Text, Images, PDFs · Qwen 3.8 Max Prime: Text, Images, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Fugu Ultra | Claude Mythos 5 | Qwen 3.8 Max Prime |
|---|---|---|---|---|
| Price | 50% | 0 | 0 | 13 |
| Inputs & features | 30% | 70 | 80 | 80 |
| Context window | 20% | 60 | 60 | 60 |
| Overall | 100% | 33/100 | 36/100 | 42/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Fugu UltraSakana AI | Claude Mythos 5Anthropic | Qwen 3.8 Max PrimeAlibaba (Qwen) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $5.00 | $10.00 | $4.00 (best) |
| Output | $30.00 | $50.00 | $12.00 (best) |
| Cached input | $0.50 | — | — |
| Blended (3:1) | $11.25 | $20.00 | $6.00 (best) |
| Long-context rate | Over 272K: $10.00 / $45.00 | Same rate | Same rate |
| Price source | Official Sakana AI API | Median of 2 providers | Median of 4 providers |
| Limits | |||
| Context window | 1,000,000 tokens | 1,000,000 tokens | 1,000,000 tokens |
| Max output | — | 128,000 tokens | 131,072 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | Yes | No |
| Audio | No | No | No |
| Video | No | No | Yes |
| Reasoning | Yeshigh · xhigh | Yes | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | fugu-ultra | — | — |
| API providers | 11 (best) | 2 | 4 |
| Released | Jun 15, 2026 | Jun 9, 2026 | Sep 23, 2026 |
| Knowledge cutoff | — | Jan 31, 2026 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Fugu Ultra$110.00
- Claude Mythos 5$200.00
- Qwen 3.8 Max Prime$64.00
Which should you choose?
Which is better: Fugu Ultra, Claude Mythos 5 or Qwen 3.8 Max Prime?
Qwen 3.8 Max Prime is the better all-round choice, scoring 42/100 against Claude Mythos 5 (36) and Fugu Ultra (33). It leads on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Fugu Ultra, Claude Mythos 5 or Qwen 3.8 Max Prime?
Qwen 3.8 Max Prime is cheaper at $4.00 input / $12.00 output per million tokens (median across 4 API providers). Fugu Ultra costs $5.00 input / $30.00 output per million tokens (official Sakana AI API price); Claude Mythos 5 costs $10.00 input / $50.00 output per million tokens (median across 2 API providers). At a typical mix of three input tokens to one output token, that is $6.00 per million tokens for Qwen 3.8 Max Prime versus $11.25 for Fugu Ultra (1.9× as much) and $20.00 for Claude Mythos 5 (3.3× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Fugu Ultra has not been scored yet, Claude Mythos 5 has not been scored yet and Qwen 3.8 Max Prime has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Fugu Ultra, Claude Mythos 5 and Qwen 3.8 Max Prime yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.
Which has the bigger context window?
Fugu Ultra, Claude Mythos 5 and Qwen 3.8 Max Prime share the same 1,000,000-token context window. Maximum output per response: Claude Mythos 5 up to 128,000, Qwen 3.8 Max Prime up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Fugu Ultra accepts text and images; Claude Mythos 5 accepts text, images and PDFs; Qwen 3.8 Max Prime accepts text, images and video. Claude Mythos 5 handles the widest range of inputs.
Are any of these open source?
No. Fugu Ultra, Claude Mythos 5 and Qwen 3.8 Max Prime are proprietary and only available through APIs and apps.
Which is newer?
Qwen 3.8 Max Prime is the newest, released Sep 23, 2026. Fugu Ultra came out Jun 15, 2026; Claude Mythos 5 came out Jun 9, 2026. Knowledge cutoff: Claude Mythos 5 Jan 31, 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
