Ornith 1.0 31B vs Claude Mythos 5 vs Seed 2.1 Pro
Claude Mythos 5 comes out ahead, 66 to 62 and 51 on our weighted score, though Seed 2.1 Pro is 11× cheaper per token.
DeepReinforce
Ornith 1.0 31B
51/100- ECI—
- Price—
- Context262K
- Our pick
AnthropicClaude Mythos 5
66/100- ECI—
- Price$10.00 / $50.00
- Context1M
ByteDance SeedSeed 2.1 Pro
62/100- ECI—
- Price$0.891 / $4.45
- Context256K
Claude Mythos 5 is our pick
Claude Mythos 5 is the better all-round choice, scoring 66/100 against Seed 2.1 Pro (62) and Ornith 1.0 31B (51). It leads on context window. Seed 2.1 Pro wins 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 priceSeed 2.1 ProSeed 2.1 Pro $1.78 · Claude Mythos 5 $20.00 per 1M tokens (3:1 blend) · Ornith 1.0 31B unpriced
- Longest contextClaude Mythos 5Claude Mythos 5 1,000,000 · Ornith 1.0 31B 262,144 · Seed 2.1 Pro 256,000 tokens
- Widest inputsClaude Mythos 5 and Seed 2.1 ProOrnith 1.0 31B: Text, Images · Claude Mythos 5: Text, Images, PDFs · Seed 2.1 Pro: Text, Images, Video
- Self-hostingOrnith 1.0 31BPublishes downloadable weights (MIT)
| Measure | Weight | Ornith 1.0 31B | Claude Mythos 5 | Seed 2.1 Pro |
|---|---|---|---|---|
| Inputs & features | 60% | 60 | 70 | 80 |
| Context window | 40% | 37 | 60 | 36 |
| Overall | 100% | 51/100 | 66/100 | 62/100 |
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 | Ornith 1.0 31BDeepReinforce | Claude Mythos 5Anthropic | Seed 2.1 ProByteDance Seed |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | — | $10.00 | $0.891 (best) |
| Output | — | $50.00 | $4.45 (best) |
| Cached input | — | — | $0.178 |
| Blended (3:1) | — | $20.00 | $1.78 (best) |
| Long-context rate | — | Same rate | Same rate |
| Price source | — | Median of 2 providers | Official Volcengine Ark API |
| Limits | |||
| Context window | 262,144 tokens | 1,000,000 tokens (best) | 256,000 tokens |
| Max output | — | 128,000 tokens | 256,000 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 | Yes | Yes | Yesminimal · low · medium · high · xhigh · max |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | No | Yes |
| Availability | |||
| Weights | OpenMIT | Proprietary | Proprietary |
| API model ID | — | — | doubao-seed-2-1-pro-260628 |
| API providers | — | 2 | 3 (best) |
| Released | Jun 25, 2026 | Jun 9, 2026 | Jun 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.
- Ornith 1.0 31B—
- Claude Mythos 5$200.00
- Seed 2.1 Pro$17.81
Which should you choose?
Which is better: Ornith 1.0 31B, Claude Mythos 5 or Seed 2.1 Pro?
Claude Mythos 5 is the better all-round choice, scoring 66/100 against Seed 2.1 Pro (62) and Ornith 1.0 31B (51). It leads on context window. Seed 2.1 Pro wins 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, Ornith 1.0 31B, Claude Mythos 5 or Seed 2.1 Pro?
Seed 2.1 Pro is cheaper at $0.891 input / $4.45 output per million tokens (official Volcengine Ark 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 $1.78 per million tokens for Seed 2.1 Pro versus $20.00 for Claude Mythos 5 (11× as much). Ornith 1.0 31B has no published per-token price.
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Ornith 1.0 31B has not been scored yet, Claude Mythos 5 has not been scored yet and Seed 2.1 Pro has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Ornith 1.0 31B, Claude Mythos 5 and Seed 2.1 Pro 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?
Claude Mythos 5 has the largest context window at 1,000,000 tokens, against 262,144 for Ornith 1.0 31B and 256,000 for Seed 2.1 Pro. Maximum output per response: Claude Mythos 5 up to 128,000, Seed 2.1 Pro up to 256,000 tokens.
Which can read images, PDFs, audio or video?
Ornith 1.0 31B accepts text and images; Claude Mythos 5 accepts text, images and PDFs; Seed 2.1 Pro accepts text, images and video. Claude Mythos 5 handles the widest range of inputs.
Are any of these open source?
Ornith 1.0 31B publishes its weights (MIT) and can be self-hosted; Claude Mythos 5 and Seed 2.1 Pro is proprietary.
Which is newer?
Ornith 1.0 31B is the newest, released Jun 25, 2026. Seed 2.1 Pro came out Jun 23, 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 Nov 2, 2026.
