Step 5 Preview vs Qwen3.5 122B-A10B vs LongCat-2.5-Preview
Too close to call on our weighted score (Qwen3.5 122B-A10B 58, Step 5 Preview 57, LongCat-2.5-Preview 52). The right pick depends on what you value most.
StepFunStep 5 Preview
57/100- ECI—
- Price$1.00 / $2.70
- Context1M
Alibaba (Qwen)Qwen3.5 122B-A10B
58/100- ECI—
- Price$0.40 / $3.20
- Context262K
Meituan (LongCat)LongCat-2.5-Preview
52/100- ECI—
- Price$0.75 / $2.95
- Context1M
Too close to call
It is close. Our weighted score puts them within 1 points (Qwen3.5 122B-A10B 58/100, Step 5 Preview 57/100, LongCat-2.5-Preview 52/100), so choose by what matters most for your work: Qwen3.5 122B-A10B 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 priceQwen3.5 122B-A10BQwen3.5 122B-A10B $1.10 · LongCat-2.5-Preview $1.30 · Step 5 Preview $1.43 per 1M tokens (3:1 blend)
- Longest contextStep 5 Preview and LongCat-2.5-PreviewStep 5 Preview 1,000,000 · LongCat-2.5-Preview 1,000,000 · Qwen3.5 122B-A10B 262,144 tokens
- Widest inputsQwen3.5 122B-A10BStep 5 Preview: Text, Images, Video · Qwen3.5 122B-A10B: Text, Images, Audio, Video · LongCat-2.5-Preview: Text, Images
- Self-hostingQwen3.5 122B-A10BPublishes downloadable weights
| Measure | Weight | Step 5 Preview | Qwen3.5 122B-A10B | LongCat-2.5-Preview |
|---|---|---|---|---|
| Price | 50% | 43 | 48 | 44 |
| Inputs & features | 30% | 80 | 90 | 60 |
| Context window | 20% | 60 | 37 | 60 |
| Overall | 100% | 57/100 | 58/100 | 52/100 |
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 | Step 5 PreviewStepFun | Qwen3.5 122B-A10BAlibaba (Qwen) | LongCat-2.5-PreviewMeituan (LongCat) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $1.00 | $0.40 (best) | $0.75 |
| Output | $2.70 (best) | $3.20 | $2.95 |
| Cached input | $0.05 | — | — |
| Blended (3:1) | $1.43 | $1.10 (best) | $1.30 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official StepFun (Global) API | Official Alibaba API | Median of 1 providers |
| Limits | |||
| Context window | 1,000,000 tokens (best) | 262,144 tokens | 1,000,000 tokens (best) |
| Max output | 1,000,000 tokens (best) | 65,536 tokens | 131,072 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | No | No |
| Audio | No | Yes | No |
| Video | Yes | Yes | No |
| Reasoning | Yeslow · medium · high | Yes | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | No |
| Availability | |||
| Weights | Proprietary | Open | Proprietary |
| API model ID | step-5-preview | qwen3.5-122b-a10b | — |
| API providers | 7 | 19 (best) | 2 |
| Released | Sep 16, 2026 | Feb 23, 2026 | Sep 25, 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.
- Step 5 Preview$15.40
- Qwen3.5 122B-A10B$10.40
- LongCat-2.5-Preview$13.40
Which should you choose?
Which is better: Step 5 Preview, Qwen3.5 122B-A10B or LongCat-2.5-Preview?
It is close. Our weighted score puts them within 1 points (Qwen3.5 122B-A10B 58/100, Step 5 Preview 57/100, LongCat-2.5-Preview 52/100), so choose by what matters most for your work: Qwen3.5 122B-A10B 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, Step 5 Preview, Qwen3.5 122B-A10B or LongCat-2.5-Preview?
Qwen3.5 122B-A10B is cheaper at $0.40 input / $3.20 output per million tokens (official Alibaba API price). LongCat-2.5-Preview costs $0.75 input / $2.95 output per million tokens (median across 1 API provider); Step 5 Preview costs $1.00 input / $2.70 output per million tokens (official StepFun (Global) API price). At a typical mix of three input tokens to one output token, that is $1.10 per million tokens for Qwen3.5 122B-A10B versus $1.30 for LongCat-2.5-Preview (1.2× as much) and $1.43 for Step 5 Preview (1.3× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Step 5 Preview has not been scored yet, Qwen3.5 122B-A10B has not been scored yet and LongCat-2.5-Preview has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Step 5 Preview, Qwen3.5 122B-A10B and LongCat-2.5-Preview 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?
Step 5 Preview and LongCat-2.5-Preview have the largest context windows (1,000,000 and 1,000,000 tokens), against 262,144 for Qwen3.5 122B-A10B. Maximum output per response: Step 5 Preview up to 1,000,000, Qwen3.5 122B-A10B up to 65,536, LongCat-2.5-Preview up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Step 5 Preview accepts text, images and video; Qwen3.5 122B-A10B accepts text, images, audio and video; LongCat-2.5-Preview accepts text and images. Qwen3.5 122B-A10B handles the widest range of inputs.
Are any of these open source?
Qwen3.5 122B-A10B publishes its weights and can be self-hosted; Step 5 Preview and LongCat-2.5-Preview is proprietary.
Which is newer?
LongCat-2.5-Preview is the newest, released Sep 25, 2026. Step 5 Preview came out Sep 16, 2026; Qwen3.5 122B-A10B came out Feb 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.
