// AI NEWS · MODEL RELEASE

StepFun Previews Step 5, a Cheap, High-Scoring Reasoning Model With a 1M-Token Context

On September 18, 2026, AI lab StepFun previewed Step 5, a reasoning model that scores 44 on the Artificial Analysis Intelligence Index at $1 in / $2.70 out per million tokens.

2026-09-19 · by Moe Ameen

Published 2026-09-19 · Updated

Short answer

Step 5 Preview is a reasoning model from StepFun, released September 18, 2026. Artificial Analysis gives it 44 on its Intelligence Index and lists it at $1.00 per million input tokens and $2.70 per million output tokens, with a 90% discount on cached input. It has a 1-million-token context window, takes text and images, and outputs text only. It runs more verbose than average.

Key takeaways

  • StepFun released Step 5 Preview on September 18, 2026.
  • It scores 44 on the Artificial Analysis Intelligence Index.
  • Artificial Analysis lists $1.00 in and $2.70 out per million tokens, with 90% off cached input.
  • It has a 1M-token context, takes text and image input, and returns text.
  • It drafts and reasons. Turning drafts into posts is a separate step.

What is StepFun Step 5 Preview?

On September 18, 2026, the AI lab StepFun previewed Step 5, a new reasoning model. Artificial Analysis, the independent benchmarking service, listed Step 5 Preview with a score of 44 on its composite Intelligence Index.

Step 5 is a reasoning model, meaning it works through problems with extended chain-of-thought before answering. Artificial Analysis lists its API price at $1.00 per million input tokens and $2.70 per million output tokens, with a 90% discount on cached input. It carries a one-million-token context window and accepts both text and image inputs, generating text output. Artificial Analysis also rates it somewhat more verbose than average: it generated about 160 million output tokens while running the Intelligence Index, against a median of 140 million.

The "Preview" label matters: this is an early, evolving release, not a finalized product, and independent figures are a snapshot that will shift as the model is refined and more evaluations land. As always with vendor and third-party benchmarks, treat the specific numbers as indicative rather than final, and confirm current pricing and specs on StepFun's own documentation before building on them.

Why does a cheap reasoning model like Step 5 matter for creators?

  • The trend that matters for creators is price, not the leaderboard rank. A capable reasoning model at $1/$2.70 per million tokens keeps pushing the cost of raw text generation down — drafting, outlining, and analysis get cheaper, which is good for anyone producing at volume.
  • A one-million-token context means you can hand the model a large corpus at once — a full transcript, a quarter of a newsletter archive, a stack of research — and get reasoning over the whole thing rather than a summary of a fragment.
  • It takes image input but only outputs text. It reads a chart or a screenshot and reasons about it; it does not produce video, images, carousels, or anything you can post. The output is words, not content.
  • Cheaper, smarter drafting does not shorten the distance to a published post. The bottleneck for most creators was never generating a draft — it is turning that draft into finished formats and getting them out across platforms on schedule.
  • It is a Preview. Specs, pricing, and availability will move, so it is a signal about where cost is heading, not a stable tool to standardize a workflow on yet.

How can creators turn Step 5 drafts into published content with Kompozy?

The useful way to read a launch like Step 5 is as another drop in the cost of raw intelligence — a strong reasoning model, a huge context window, and a low per-token price. What it does not change is the part that actually eats a creator's week: a reasoned draft is not a set of published posts. Step 5 will read your long transcript and write you a sharp brief; it will not cut the clip, design the carousel, film the avatar, caption the short, or schedule any of it. That gap between "good text out of a model" and "finished content live on eight platforms" is exactly where Kompozy lives.

Here is how a creator acts on this today. Use a model like Step 5 for what it is best at — reasoning over a long source to produce a tight draft or outline — then bring that source into Kompozy and let it manufacture the rest. Under a Persona Brief that locks your voice and banned words, Kompozy fans one input into the formats a text model can't: Clipped Shorts and captioned Persona Shorts fronted by a face-locked avatar, brand-exact Carousel Posts, quote graphics, photo posts, a blog article, and an email newsletter. Then Autopilot schedules and publishes the batch across the eight social platforms plus blog and email behind a per-post review gate. Cheaper reasoning lowers the cost of the first draft; Kompozy is what turns that draft into a week of on-brand, published content.

What are the quick takeaways?

  • StepFun previewed Step 5, a reasoning model, on September 18, 2026.
  • It scores 44 on the Artificial Analysis Intelligence Index, with a 1M-token context and text + image input, text output.
  • Artificial Analysis lists it at $1.00 per million input tokens and $2.70 per million output tokens, with a 90% cached-input discount; it runs more verbose than average.
  • For creators, the takeaway is cheaper drafting — not a shorter path to a published post. A model outputs text; turning that into finished, scheduled multi-platform content is the separate job Kompozy does.

What does this look like in Kompozy?

This carousel is a real output from the Kompozy workspace. It shows what a text draft can become once it is laid out as slides.

Five-slide carousel generated in Kompozy, slide 1Five-slide carousel generated in Kompozy, slide 2Five-slide carousel generated in Kompozy, slide 3Five-slide carousel generated in Kompozy, slide 4Five-slide carousel generated in Kompozy, slide 5
Real output · Kompozy Carousel format · from the Kompozy workspace

Who is this for, and who should skip it?

Best for:

  • Creators who want cheap drafting and analysis through an API
  • Anyone working with very long sources like full transcripts
  • Developers testing new reasoning models

Not ideal for:

  • People who need images or video from the model
  • Teams that need a stable, final model rather than a preview
  • Users who want short, terse answers, since it runs verbose

Frequently asked questions

What is StepFun Step 5?

Step 5 is a reasoning model previewed by the AI lab StepFun on September 18, 2026. It uses chain-of-thought reasoning, carries a one-million-token context window, and accepts text and image inputs while generating text output. Independent benchmarking from Artificial Analysis put its Intelligence Index score at 44.

How much does Step 5 cost?

Artificial Analysis lists Step 5 Preview at $1.00 per million input tokens and $2.70 per million output tokens, with a 90% discount on cached input. Because it is a preview, confirm current pricing on StepFun's documentation before relying on it.

Can Step 5 make videos or social posts?

No. Step 5 outputs text. It can read images and reason over them, but it does not generate video, images, carousels, or captions, and it publishes nothing. To turn its output into finished, published content you pair it with a generation-and-publishing engine like Kompozy.

What can creators do with a cheaper reasoning model like Step 5?

Use it for the drafting and reasoning step — outlining a piece, analyzing a long transcript, synthesizing research across its million-token context. Then bring that source into Kompozy, which fans one input into clips, persona video, carousels, quote graphics, a blog, and a newsletter, and schedules them across the eight social platforms plus blog and email.

How do we know this?

We checked every figure, date, quote and product claim on this page against the sources listed below on 2026-10-23, and removed or rewrote anything we could not confirm. Score, price, context and verbosity were read off Artificial Analysis today. We updated the cache discount to 90% and removed speed and ranking figures that no longer match. Kompozy plan and format details come from kompozy.io/pricing.

Sources

  1. Artificial Analysis — Step 5 Preview (read 2026-10-23)
  2. Kompozy — Pricing and plans (read 2026-10-23)

Related news

← All AI news · Get started →