AI Models · Open-Source vs Paid

Step 5 Preview Open vs Nano Banana 2.1 Paid

Step 5 Preview vs Nano Banana 2.1 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

Step 5 PreviewOpenStepfun
$1 /M input
$2.7 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window1M tokens
MultimodalYes
Self-hostYes
Nano Banana 2.1PaidGoogle
$1.5 /M input
$7.5 /M outputManaged API (no infra to run)
TypeProprietary
Context window66K tokens
MultimodalYes
Self-hostNo
Choose Step 5 Preview if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Nano Banana 2.1 if you want frontier capability through a managed API with zero infrastructure to run.

Step 5 Preview vs Nano Banana 2.1 specs

SpecStep 5 PreviewNano Banana 2.1Winner
MakerStepfunGoogle–
TypeOpen-weightProprietaryStep 5 Preview
Context window1M tokens66K tokensStep 5 Preview
Input price$1/M · free self-host$1.5/MStep 5 Preview
Output price$2.7/M · free self-host$7.5/MStep 5 Preview
Vision / multimodalYesYes= Tie
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)Step 5 Preview
LicenseOpen weightsProprietaryStep 5 Preview

Price gap & when to choose each

2.8×cheaper per output token

Step 5 Preview is ~2.8× cheaper than Nano Banana 2.1 on output tokens ($2.7 vs $7.5 per M tokens).

Choose Step 5 Preview if…
  • You want to self-host or run on your cloud
  • You need the longer 1M context window
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
Choose Nano Banana 2.1 if…
  • You want frontier performance through a managed API
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityStep 5 PreviewNano Banana 2.1
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✓✗

Benchmarks: Step 5 Preview vs Nano Banana 2.1

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Step 5 Preview
Nano Banana 2.1
Intelligence index
43.7
–
Humanity's Last Exam
46.5%
–
Long Context Reasoning
88.3%
–
SciCode
58.9%
–
Speed
201.5 tok/s
–
Latency
0.87s
–
Intelligence per $
30.7
–

Benchmark data by Artificial Analysis.

How Step 5 Preview and Nano Banana 2.1 score

🏆 Best value & openness: Step 5 Preview (4.9 vs 2.9 / 5)
CriterionStep 5 PreviewNano Banana 2.1
Cost-efficiency4.54.0
Context window5.03.0
Openness5.01.5
Self-hosting5.01.0
Multimodality5.05.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

Step 5 Preview Open

Stepfun · Open-weight

Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...

Nano Banana 2.1 Paid

Google · Proprietary

Nano Banana 2.1 (Gemini Nano Banana 2.1) is Google's image generation and editing model on the Flash tier, succeeding Nano Banana 2 and Nano Banana Pro. It improves product recontextualization,...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Step 3.7 FlashStep 3.5 Flash

Frequently asked questions

Is Step 5 Preview as good as Nano Banana 2.1?

Step 5 Preview is open-weight and competitive on many tasks, but Nano Banana 2.1 may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run Step 5 Preview locally?

Yes. Step 5 Preview has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Nano Banana 2.1 is API-only and cannot be self-hosted.

How much cheaper is Step 5 Preview?

Step 5 Preview costs $2.7/M output vs $7.5/M for Nano Banana 2.1 — roughly 3x cheaper via API, and free if you self-host.

Step 5 Preview vs Nano Banana 2.1 — which should I pick in 2026?

Choose Step 5 Preview if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Nano Banana 2.1 if you want frontier capability through a managed API with zero infrastructure to run.

People also compare

Explore more open-source AI

Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.

Open the leaderboard →