Seed 2.1 Pro vs Claude Mythos 5 vs MiMo-V2.5-Pro-UltraSpeed
Seed 2.1 Pro comes out ahead, 50 to 43 and 36 on our weighted score, though MiMo-V2.5-Pro-UltraSpeed is 8% cheaper per token.
- Our pick
ByteDance SeedSeed 2.1 Pro
50/100- ECI—
- Price$0.891 / $4.45
- Context256K
AnthropicClaude Mythos 5
36/100- ECI—
- Price$10.00 / $50.00
- Context1M
XiaomiMiMo-V2.5-Pro-UltraSpeed
43/100- ECI—
- Price$1.30 / $2.61
- Context1.05M
Seed 2.1 Pro is our pick
Seed 2.1 Pro is the better all-round choice, scoring 50/100 against MiMo-V2.5-Pro-UltraSpeed (43) and Claude Mythos 5 (36). MiMo-V2.5-Pro-UltraSpeed wins 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 priceMiMo-V2.5-Pro-UltraSpeedMiMo-V2.5-Pro-UltraSpeed $1.63 · Seed 2.1 Pro $1.78 · Claude Mythos 5 $20.00 per 1M tokens (3:1 blend)
- Longest contextMiMo-V2.5-Pro-UltraSpeedMiMo-V2.5-Pro-UltraSpeed 1,048,576 · Claude Mythos 5 1,000,000 · Seed 2.1 Pro 256,000 tokens
- Widest inputsSeed 2.1 Pro and Claude Mythos 5Seed 2.1 Pro: Text, Images, Video · Claude Mythos 5: Text, Images, PDFs · MiMo-V2.5-Pro-UltraSpeed: Text
- Self-hostingMiMo-V2.5-Pro-UltraSpeedPublishes downloadable weights
| Measure | Weight | Seed 2.1 Pro | Claude Mythos 5 | MiMo-V2.5-Pro-UltraSpeed |
|---|---|---|---|---|
| Price | 50% | 38 | 0 | 40 |
| Inputs & features | 30% | 80 | 80 | 35 |
| Context window | 20% | 36 | 60 | 61 |
| Overall | 100% | 50/100 | 36/100 | 43/100 |
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 | Seed 2.1 ProByteDance Seed | Claude Mythos 5Anthropic | MiMo-V2.5-Pro-UltraSpeedXiaomi |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.891 (best) | $10.00 | $1.30 |
| Output | $4.45 | $50.00 | $2.61 (best) |
| Cached input | $0.178 | — | $0.011 (best) |
| Blended (3:1) | $1.78 | $20.00 | $1.63 (best) |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Volcengine Ark API | Median of 2 providers | Official Xiaomi API |
| Limits | |||
| Context window | 256,000 tokens | 1,000,000 tokens | 1,048,576 tokens (best) |
| Max output | 256,000 tokens (best) | 128,000 tokens | 131,072 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | No |
| PDFs | No | Yes | No |
| Audio | No | No | No |
| Video | Yes | No | No |
| Reasoning | Yesminimal · low · medium · high · xhigh · max | Yes | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Open |
| API model ID | doubao-seed-2-1-pro-260628 | — | mimo-v2.5-pro-ultraspeed |
| API providers | 2 (best) | 2 (best) | 1 |
| Released | Jun 23, 2026 | Jun 9, 2026 | Jun 8, 2026 |
| Knowledge cutoff | — | Jan 31, 2026 | Dec 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Seed 2.1 Pro$17.81
- Claude Mythos 5$200.00
- MiMo-V2.5-Pro-UltraSpeed$18.27
Which should you choose?
Which is better: Seed 2.1 Pro, Claude Mythos 5 or MiMo-V2.5-Pro-UltraSpeed?
Seed 2.1 Pro is the better all-round choice, scoring 50/100 against MiMo-V2.5-Pro-UltraSpeed (43) and Claude Mythos 5 (36). MiMo-V2.5-Pro-UltraSpeed wins 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, Seed 2.1 Pro, Claude Mythos 5 or MiMo-V2.5-Pro-UltraSpeed?
MiMo-V2.5-Pro-UltraSpeed is cheaper at $1.30 input / $2.61 output per million tokens (official Xiaomi API price). Seed 2.1 Pro costs $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 $1.63 per million tokens for MiMo-V2.5-Pro-UltraSpeed versus $1.78 for Seed 2.1 Pro (1.1× as much) and $20.00 for Claude Mythos 5 (12× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Seed 2.1 Pro has not been scored yet, Claude Mythos 5 has not been scored yet and MiMo-V2.5-Pro-UltraSpeed has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Seed 2.1 Pro, Claude Mythos 5 and MiMo-V2.5-Pro-UltraSpeed 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?
MiMo-V2.5-Pro-UltraSpeed has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Mythos 5 and 256,000 for Seed 2.1 Pro. Maximum output per response: Seed 2.1 Pro up to 256,000, Claude Mythos 5 up to 128,000, MiMo-V2.5-Pro-UltraSpeed up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Seed 2.1 Pro accepts text, images and video; Claude Mythos 5 accepts text, images and PDFs; MiMo-V2.5-Pro-UltraSpeed accepts text. Seed 2.1 Pro handles the widest range of inputs.
Are any of these open source?
MiMo-V2.5-Pro-UltraSpeed publishes its weights and can be self-hosted; Seed 2.1 Pro and Claude Mythos 5 is proprietary.
Which is newer?
Seed 2.1 Pro is the newest, released Jun 23, 2026. Claude Mythos 5 came out Jun 9, 2026; MiMo-V2.5-Pro-UltraSpeed came out Jun 8, 2026. Knowledge cutoff: Claude Mythos 5 Jan 31, 2026, MiMo-V2.5-Pro-UltraSpeed Dec 2024.
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.
