Step 3.5 Flash vs Step 3.5 Flash 2603
Too close to call on our weighted score (Step 3.5 Flash 62, Step 3.5 Flash 2603 62). The right pick depends on what you value most.
StepFunStep 3.5 Flash
62/100- ECI—
- Price$0.10 / $0.30
- Context256K
- StepFun
Step 3.5 Flash 2603
62/100- ECI—
- Price$0.10 / $0.30
- Context256K
Add a model
Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within a point (Step 3.5 Flash 62/100, Step 3.5 Flash 2603 62/100), so choose by what matters most for your work: Step 3.5 Flash 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 priceSame priceStep 3.5 Flash $0.15 · Step 3.5 Flash 2603 $0.15 per 1M tokens (3:1 blend)
- Longest contextAbout the sameStep 3.5 Flash 256,000 · Step 3.5 Flash 2603 256,000 tokens
- Widest inputsSame inputsStep 3.5 Flash: Text · Step 3.5 Flash 2603: Text
- Self-hostingAll open weightsEvery model here can be downloaded and run on your own hardware
| Measure | Weight | Step 3.5 Flash | Step 3.5 Flash 2603 |
|---|---|---|---|
| Price | 50% | 89 | 89 |
| Inputs & features | 30% | 35 | 35 |
| Context window | 20% | 36 | 36 |
| Overall | 100% | 62/100 | 62/100 |
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 3.5 FlashStepFun | Step 3.5 Flash 2603StepFun |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.10 | $0.10 |
| Output | $0.30 | $0.30 |
| Cached input | $0.02 | $0.02 |
| Blended (3:1) | $0.15 | $0.15 |
| Long-context rate | Same rate | Same rate |
| Price source | Official StepFun (Global) API | Official StepFun (Global) API |
| Limits | ||
| Context window | 256,000 tokens | 256,000 tokens |
| Max output | 256,000 tokens | 256,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | No | No |
| PDFs | No | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yeslow · high | Yeslow · high |
| Tool calling | Yes | Yes |
| Structured output | No | No |
| Availability | ||
| Weights | Open | Open |
| API model ID | step-3.5-flash | step-3.5-flash-2603 |
| API providers | 8 (best) | 3 |
| Released | Jan 29, 2026 | Apr 2, 2026 |
| Knowledge cutoff | Jan 2025 | Jan 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Step 3.5 Flash$1.60
- Step 3.5 Flash 2603$1.60
Which should you choose?
Which is better: Step 3.5 Flash or Step 3.5 Flash 2603?
It is close. Our weighted score puts them within a point (Step 3.5 Flash 62/100, Step 3.5 Flash 2603 62/100), so choose by what matters most for your work: Step 3.5 Flash 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 3.5 Flash or Step 3.5 Flash 2603?
Step 3.5 Flash and Step 3.5 Flash 2603 cost the same: $0.10 input / $0.30 output per million tokens.
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Step 3.5 Flash has not been scored yet and Step 3.5 Flash 2603 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Step 3.5 Flash and Step 3.5 Flash 2603 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Step 3.5 Flash and Step 3.5 Flash 2603 share the same 256,000-token context window. Maximum output per response: Step 3.5 Flash up to 256,000, Step 3.5 Flash 2603 up to 256,000 tokens.
Which can read images, PDFs, audio or video?
Step 3.5 Flash accepts text; Step 3.5 Flash 2603 accepts text. They handle the same number of input types.
Are any of these open source?
Yes, both publish their weights, so you can self-host them.
Which is newer?
Step 3.5 Flash 2603 is the newest, released Apr 2, 2026. Step 3.5 Flash came out Jan 29, 2026. Knowledge cutoff: Step 3.5 Flash Jan 2025, Step 3.5 Flash 2603 Jan 2025.
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.
