Step 5 Preview vs Qwen3.8 Flash vs LongCat-2.5-Preview
Qwen3.8 Flash comes out ahead, 76 to 57 and 52 on our weighted score, and it is the cheaper option too.
StepFunStep 5 Preview
57/100- ECI—
- Price$1.00 / $2.70
- Context1M
- Our pick
Alibaba (Qwen)Qwen3.8 Flash
76/100- ECI—
- Price$0.15 / $0.47
- Context1M
Meituan (LongCat)LongCat-2.5-Preview
52/100- ECI—
- Price$0.75 / $2.95
- Context1M
Qwen3.8 Flash is our pick
Qwen3.8 Flash is the better all-round choice, scoring 76/100 against Step 5 Preview (57) and LongCat-2.5-Preview (52). It leads 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 priceQwen3.8 FlashQwen3.8 Flash $0.23 · LongCat-2.5-Preview $1.30 · Step 5 Preview $1.43 per 1M tokens (3:1 blend)
- Longest contextAbout the sameStep 5 Preview 1,000,000 · Qwen3.8 Flash 1,000,000 · LongCat-2.5-Preview 1,000,000 tokens
- Widest inputsStep 5 Preview and Qwen3.8 FlashStep 5 Preview: Text, Images, Video · Qwen3.8 Flash: Text, Images, Video · LongCat-2.5-Preview: Text, Images
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Step 5 Preview | Qwen3.8 Flash | LongCat-2.5-Preview |
|---|---|---|---|---|
| Price | 50% | 43 | 80 | 44 |
| Inputs & features | 30% | 80 | 80 | 60 |
| Context window | 20% | 60 | 60 | 60 |
| Overall | 100% | 57/100 | 76/100 | 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 | Qwen3.8 FlashAlibaba (Qwen) | LongCat-2.5-PreviewMeituan (LongCat) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $1.00 | $0.15 (best) | $0.75 |
| Output | $2.70 | $0.47 (best) | $2.95 |
| Cached input | $0.05 | $0.016 (best) | — |
| Blended (3:1) | $1.43 | $0.23 (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 | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 1,000,000 tokens (best) | 131,072 tokens | 131,072 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | No | No |
| Audio | No | No | No |
| Video | Yes | Yes | No |
| Reasoning | Yeslow · medium · high | Yeslow · medium · xhigh | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | step-5-preview | qwen3.8-flash | — |
| API providers | 7 | 23 (best) | 2 |
| Released | Sep 16, 2026 | Aug 26, 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
- Qwen3.8 Flash$2.44
- LongCat-2.5-Preview$13.40
Which should you choose?
Which is better: Step 5 Preview, Qwen3.8 Flash or LongCat-2.5-Preview?
Qwen3.8 Flash is the better all-round choice, scoring 76/100 against Step 5 Preview (57) and LongCat-2.5-Preview (52). It leads 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, Qwen3.8 Flash or LongCat-2.5-Preview?
Qwen3.8 Flash is cheaper at $0.15 input / $0.47 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 $0.23 per million tokens for Qwen3.8 Flash versus $1.30 for LongCat-2.5-Preview (5.7× as much) and $1.43 for Step 5 Preview (6.2× 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, Qwen3.8 Flash 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, Qwen3.8 Flash 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, Qwen3.8 Flash and LongCat-2.5-Preview share the same 1,000,000-token context window. Maximum output per response: Step 5 Preview up to 1,000,000, Qwen3.8 Flash up to 131,072, 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; Qwen3.8 Flash accepts text, images and video; LongCat-2.5-Preview accepts text and images. Step 5 Preview handles the widest range of inputs.
Are any of these open source?
No. Step 5 Preview, Qwen3.8 Flash and LongCat-2.5-Preview are proprietary and only available through APIs and apps.
Which is newer?
LongCat-2.5-Preview is the newest, released Sep 25, 2026. Step 5 Preview came out Sep 16, 2026; Qwen3.8 Flash came out Aug 26, 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.
