by Stepfun
StepFun: Step 3.5 Flash.
text
open weights
262K ctx
Cheapest input
$0.09/M
on DeepInfra
Cheapest output
$0.3/M
on DeepInfra
Fastest
107 tok/s
on OpenRouter
Hosted equiv.
~$0.11/hr
@ 100 tok/s on DeepInfra
Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....
Where to use it
Cheapest hosted endpoints.
Performance
Speed across providers.
Tokens/sec and time-to-first-token measured against the same prompt template on each provider's API.
| Provider | Tokens/sec | TTFT | Total |
|---|---|---|---|
| OpenRouter | 107.1 | — | 4667 ms |
FAQ
Frequently asked.
How do I run StepFun: Step 3.5 Flash?
StepFun: Step 3.5 Flash is open-weight, so you can self-host on rented GPUs. See the Run It Yourself tab for GPU configurations + cost estimates, or use one of the hosted inference providers listed on this page.
Where can I access StepFun: Step 3.5 Flash?
StepFun: Step 3.5 Flash is available via DeepInfra, OpenRouter. Each access option lists its own pricing (per million tokens or hourly hosting).
How much does it cost to run StepFun: Step 3.5 Flash?
API pricing starts at $0.09/M input tokens and $0.3/M output tokens. Self-hosting cost depends on the GPU you rent — see the Run It Yourself tab.
Is StepFun: Step 3.5 Flash open-source or proprietary?
StepFun: Step 3.5 Flash is open-weight under the license. You can download and self-host it.
API pricing
Per provider
What it costs per month across providers.
Estimate your monthly bill for StepFun: Step 3.5 Flash across every host that publishes per-token pricing. Slide your token volumes; the chart + table re-rank cheapest-first.
Cheapest
$1.5
OpenRouter
$/M input
$0.09
per million tokens
$/M output
$0.3
per million tokens
Providers
2
with priced rows
Monthly bill
Cheapest provider on the left.
Total monthly cost — input + output tokens combined.
Loading...
Bill breakdown.
Full calculator
Want to compare token volumes across other models too?
Open the standalone API pricing tool →
Context window
How much it can remember.
262K tokens
≈ 196,608 English words
4K
32K
128K
1M
Capabilities
What it can do.
·
Vision input
·
Audio input
·
Video input
·
Function calling
·
Tool use
·
JSON mode
✓
Streaming
·
Fine-tuning