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Head-to-head comparison

o4 Mini vs Step 3.7 Flash

o4 Mini (OpenAI) and Step 3.7 Flash (StepFun) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 18 August 2026

As of 18 August 2026, o4 Mini holds the stronger ModelCap Index position (#57 vs #65); Step 3.7 Flash is 3.8× cheaper per output token ($1.15/1M vs $4.40/1M); Step 3.7 Flash offers the longer context window (262K vs 200K tokens); and Step 3.7 Flash ships open weights.

Which should you choose?

Choose o4 Mini if…

  • you want the stronger overall ModelCap Index position — #57 against #65 (43.4 vs 39.6 points).

Choose Step 3.7 Flash if…

  • API cost matters — $1.15/1M output tokens against $4.40/1M, about 3.8× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.20/1M against $1.10/1M.
  • you need the longer context window — 262K tokens against 200K.
  • you want to self-host: Step 3.7 Flash ships open weights while o4 Mini is api only.
  • you want provider choice — 3 listed API providers against 1.
  • Artificial Analysis Intelligence Index is your yardstick — 30.9 against 26.1.
  • you want the more recently listed model — Step 3.7 Flash was listed 28 May 2026, o4 Mini 16 April 2025.

o4 Mini vs Step 3.7 Flash: specs, pricing and context

Specification comparison of o4 Mini and Step 3.7 Flash
Fieldo4 MiniOpenAIStep 3.7 FlashStepFun
ModelCap Index position#57#65
Index score43.439.6
EvidenceMeasuredMeasured
Input price / 1M tokens$1.10$0.20
Output price / 1M tokens$4.40$1.15
Context window200K tokens262K tokens
Max output tokens100K256K
API providers listed13
Weight accessAPI onlyOpen weights
Input modalitiesImage, Text, FileText, Image, Video
First listed16 April 202528 May 2026
PublisherOpenAIStepFun

Evidence: 4 public benchmark observations across 4 boards · 1 public benchmark observation across 1 board. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: o4 Mini vs Step 3.7 Flash

Public benchmark boards where o4 Mini or Step 3.7 Flash has a published result
Boardo4 MiniStep 3.7 FlashLeads
Arena codingArena (LMArena)14331426–1440—Only one result
ARC-AGI-2ARC Prize Foundation6.1%High—Only one result
SWE-benchSWE-bench (Princeton / SWE-agent team)45.0%—Only one result
BFCL V4UC Berkeley (Gorilla)53.2Function calling—Only one result
Artificial Analysis Intelligence IndexArtificial Analysis26.1intelligence-index30.9intelligence-indexStep 3.7 Flash

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

o4 Mini vs Step 3.7 Flash: common questions

Is o4 Mini better than Step 3.7 Flash?

o4 Mini ranks higher on the ModelCap Index as of 18 August 2026: #57 against #65. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is o4 Mini cheaper than Step 3.7 Flash?

Step 3.7 Flash is cheaper on output tokens: $1.15/1M against $4.40/1M. Input tokens are $1.10/1M for o4 Mini and $0.20/1M for Step 3.7 Flash. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, o4 Mini or Step 3.7 Flash?

Step 3.7 Flash has the larger context window: 262K tokens against 200K.

Which is better for coding, o4 Mini or Step 3.7 Flash?

The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.

Are o4 Mini and Step 3.7 Flash open-weight models?

o4 Mini: API only. Step 3.7 Flash: Open weights. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run o4 Mini and Step 3.7 Flash?

ModelCap currently lists 1 API provider for o4 Mini and 3 for Step 3.7 Flash, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this o4 Mini vs Step 3.7 Flash comparison?

Every figure comes from the sealed ModelCap dataset published 18 August 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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