LongCat-2.5-Preview vs Sakana Namazu vs Seed 2.1 Pro
Too close to call on our weighted score (LongCat-2.5-Preview 52, Sakana Namazu 51, Seed 2.1 Pro 50). The right pick depends on what you value most.
Meituan (LongCat)LongCat-2.5-Preview
52/100- ECI—
- Price$0.75 / $2.95
- Context1M
Sakana AI
Sakana Namazu
51/100- ECI—
- Price$0.95 / $4.00
- Context262K
ByteDance SeedSeed 2.1 Pro
50/100- ECI—
- Price$0.891 / $4.45
- Context256K
Too close to call
It is close. Our weighted score puts them within 1 points (LongCat-2.5-Preview 52/100, Sakana Namazu 51/100, Seed 2.1 Pro 50/100), so choose by what matters most for your work: LongCat-2.5-Preview on price and LongCat-2.5-Preview for long inputs. 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 priceLongCat-2.5-PreviewLongCat-2.5-Preview $1.30 · Sakana Namazu $1.71 · Seed 2.1 Pro $1.78 per 1M tokens (3:1 blend)
- Longest contextLongCat-2.5-PreviewLongCat-2.5-Preview 1,000,000 · Sakana Namazu 262,144 · Seed 2.1 Pro 256,000 tokens
- Widest inputsSakana Namazu and Seed 2.1 ProLongCat-2.5-Preview: Text, Images · Sakana Namazu: Text, Images, PDFs · Seed 2.1 Pro: Text, Images, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | LongCat-2.5-Preview | Sakana Namazu | Seed 2.1 Pro |
|---|---|---|---|---|
| Price | 50% | 44 | 39 | 38 |
| Inputs & features | 30% | 60 | 80 | 80 |
| Context window | 20% | 60 | 37 | 36 |
| Overall | 100% | 52/100 | 51/100 | 50/100 |
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 | LongCat-2.5-PreviewMeituan (LongCat) | Sakana NamazuSakana AI | Seed 2.1 ProByteDance Seed |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.75 (best) | $0.95 | $0.891 |
| Output | $2.95 (best) | $4.00 | $4.45 |
| Cached input | — | $0.15 (best) | $0.178 |
| Blended (3:1) | $1.30 (best) | $1.71 | $1.78 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Median of 1 providers | Official Sakana AI API | Official Volcengine Ark API |
| Limits | |||
| Context window | 1,000,000 tokens (best) | 262,144 tokens | 256,000 tokens |
| Max output | 131,072 tokens | 65,536 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 | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | — | sakana-namazu | doubao-seed-2-1-pro-260628 |
| API providers | 2 | 5 (best) | 2 |
| Released | Sep 25, 2026 | Aug 3, 2026 | Jun 23, 2026 |
| Knowledge cutoff | — | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- LongCat-2.5-Preview$13.40
- Sakana Namazu$17.50
- Seed 2.1 Pro$17.81
Which should you choose?
Which is better: LongCat-2.5-Preview, Sakana Namazu or Seed 2.1 Pro?
It is close. Our weighted score puts them within 1 points (LongCat-2.5-Preview 52/100, Sakana Namazu 51/100, Seed 2.1 Pro 50/100), so choose by what matters most for your work: LongCat-2.5-Preview on price and LongCat-2.5-Preview for long inputs. 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, LongCat-2.5-Preview, Sakana Namazu or Seed 2.1 Pro?
LongCat-2.5-Preview is cheaper at $0.75 input / $2.95 output per million tokens (median across 1 API provider). Sakana Namazu costs $0.95 input / $4.00 output per million tokens (official Sakana AI API price); Seed 2.1 Pro costs $0.891 input / $4.45 output per million tokens (official Volcengine Ark API price). At a typical mix of three input tokens to one output token, that is $1.30 per million tokens for LongCat-2.5-Preview versus $1.71 for Sakana Namazu (1.3× as much) and $1.78 for Seed 2.1 Pro (1.4× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. LongCat-2.5-Preview has not been scored yet, Sakana Namazu 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 LongCat-2.5-Preview, Sakana Namazu 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?
LongCat-2.5-Preview has the largest context window at 1,000,000 tokens, against 262,144 for Sakana Namazu and 256,000 for Seed 2.1 Pro. Maximum output per response: LongCat-2.5-Preview up to 131,072, Sakana Namazu up to 65,536, Seed 2.1 Pro up to 256,000 tokens.
Which can read images, PDFs, audio or video?
LongCat-2.5-Preview accepts text and images; Sakana Namazu accepts text, images and PDFs; Seed 2.1 Pro accepts text, images and video. Sakana Namazu handles the widest range of inputs.
Are any of these open source?
No. LongCat-2.5-Preview, Sakana Namazu and Seed 2.1 Pro are proprietary and only available through APIs and apps.
Which is newer?
LongCat-2.5-Preview is the newest, released Sep 25, 2026. Sakana Namazu came out Aug 3, 2026; Seed 2.1 Pro came out Jun 23, 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.
