Claude Mythos 5.1 vs Hy4 preview
Claude Mythos 5.1 comes out ahead, 66 to 45 on our weighted score.
- Our pick
AnthropicClaude Mythos 5.1
66/100- ECI—
- Price—
- Context1M
TencentHy4 preview
45/100- ECI—
- Price$0.834 / $2.50
- Context1.02M
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Make it a three-way comparison.
Claude Mythos 5.1 is our pick
Claude Mythos 5.1 is the better all-round choice, scoring 66/100 against Hy4 preview (45). It leads on inputs & features. The score weighs inputs & features 60%, context window 40%. 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 priceHy4 previewHy4 preview $1.25 per 1M tokens (3:1 blend) · Claude Mythos 5.1 unpriced
- Longest contextHy4 previewHy4 preview 1,024,000 · Claude Mythos 5.1 1,000,000 tokens
- Widest inputsClaude Mythos 5.1Claude Mythos 5.1: Text, Images, PDFs · Hy4 preview: Text
- Self-hostingHy4 previewPublishes downloadable weights
| Measure | Weight | Claude Mythos 5.1 | Hy4 preview |
|---|---|---|---|
| Inputs & features | 60% | 70 | 35 |
| Context window | 40% | 60 | 60 |
| Overall | 100% | 66/100 | 45/100 |
Left out because at least one model lacks the data: capability and price. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Mythos 5.1Anthropic | Hy4 previewTencent |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | — | $0.834 |
| Output | — | $2.50 |
| Cached input | — | $0.042 |
| Blended (3:1) | — | $1.25 |
| Long-context rate | — | Same rate |
| Price source | — | Official Tencent TokenHub API |
| Limits | ||
| Context window | 1,000,000 tokens | 1,024,000 tokens (best) |
| Max output | 128,000 tokens (best) | 64,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | Yes | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yes | Yeshigh |
| Tool calling | Yes | Yes |
| Structured output | No | No |
| Availability | ||
| Weights | Proprietary | Open |
| API model ID | — | hy4-preview |
| API providers | — | 17 |
| Released | Sep 1, 2026 | Aug 28, 2026 |
| Knowledge cutoff | Jun 2026 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Claude Mythos 5.1—
- Hy4 preview$13.34
Which should you choose?
Which is better: Claude Mythos 5.1 or Hy4 preview?
Claude Mythos 5.1 is the better all-round choice, scoring 66/100 against Hy4 preview (45). It leads on inputs & features. The score weighs inputs & features 60%, context window 40%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Claude Mythos 5.1 or Hy4 preview?
Hy4 preview is cheaper at $0.834 input / $2.50 output per million tokens (official Tencent TokenHub API price). . At a typical mix of three input tokens to one output token, that is $1.25 per million tokens for Hy4 preview versus . Claude Mythos 5.1 has no published per-token price.
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Claude Mythos 5.1 has not been scored yet and Hy4 preview has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Mythos 5.1 and Hy4 preview yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Hy4 preview has the largest context window at 1,024,000 tokens, against 1,000,000 for Claude Mythos 5.1. Maximum output per response: Claude Mythos 5.1 up to 128,000, Hy4 preview up to 64,000 tokens.
Which can read images, PDFs, audio or video?
Claude Mythos 5.1 accepts text, images and PDFs; Hy4 preview accepts text. Claude Mythos 5.1 handles the widest range of inputs.
Are any of these open source?
Hy4 preview publishes its weights and can be self-hosted; Claude Mythos 5.1 is proprietary.
Which is newer?
Claude Mythos 5.1 is the newest, released Sep 1, 2026. Hy4 preview came out Aug 28, 2026. Knowledge cutoff: Claude Mythos 5.1 Jun 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 Nov 2, 2026.
