Step 3.5 Flash

Feb 2026
Older versionReplace withStep 3.7 FlashNewer version
Step 3.5 Flash
Compare in
on
—per task?
$0.10 / $0.30per 1M in / out?
—output speed?
256Kcontext

Ranking?

Retired models are left out of the current rankings.

Alternatives?

ModelScoreCostPer taskWhat changes
Nothing here yet.

Run it yourself

Fits onhardware needs not verified yet
Licencenot verified

Benchmarks

all categories
Chat & Knowledge
AA Omniscience Index · Step 3.5 Flash · thinking-41.8
CritPt (physics) · Step 3.5 Flash · thinking2.5
AA Intelligence Index 4.3.2 · Step 3.5 Flash · thinking≈16.6
AA Omniscience · Accuracy · Step 3.5 Flash · thinking23.6
AA Omniscience · Hallucination Rate · Step 3.5 Flash · thinking85.7
AA-LCR (long context) 1.1 · Step 3.5 Flash · thinking50
GPQA Diamond · Step 3.5 Flash · thinking83.1
Humanity's Last Exam · Step 3.5 Flash · thinking21.1
Coding
Terminal-Bench Hard (version unstated) · Step 3.5 Flash · thinking27.3
Agents & Tool Use
τ²-bench · AA · Step 3.5 Flash · thinking94.4
Writing & Language
IFBench (instructions) · Step 3.5 Flash · thinking64.6

FAQ

How much does Step 3.5 Flash cost?›

$0.10 per 1M input tokens and $0.30 per 1M output tokens.

Is Step 3.5 Flash free to use?›

There is no free API; the cheapest paid price is $0.10 per 1M input tokens. The weights are open, so you can run it yourself.

How can I use Step 3.5 Flash?›

Through the StepFun API.

What is the context window of Step 3.5 Flash?›

256K tokens.

When was Step 3.5 Flash released? Is there a newer version?›

Released 2026-02-02. It has been superseded by Step 3.5 Flash.

Is Step 3.5 Flash open source?›

Yes, the weights are open.

Can I run Step 3.5 Flash locally?›

The weights are open and can be self-hosted; hardware needs are not confirmed yet.

What is Step 3.5 Flash?›

Step 3.5 Flash is an open-weights language model from StepFun, released Feb 2026.