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StepFun · Released Oct 8, 2026

Step 5 Preview

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...

ReasoningOpen weightsVision
  • Top 12%SciCode
  • Top 21%CritPt
  • Top 33%WebDev Arena
Compare in showdown → OpenRouter ↗ All StepFun models
Released
Oct 8 2026
Context window
1M 64K out
Input / 1M tokens
$1.00
Output / 1M tokens
$2.70

Where to run it

4 providers compared

All 4 providers charge the same: $1.00 / $2.70 per 1M input / output tokens.

ProviderInputOutputCache readContextMax outputUptimevs. best
InferenceNetFP4 $1.00 $2.70 $0.051M131K100%24h Cheapest
StepFunFP8 $1.00 $2.70 $0.101M64K100%24h Cheapest
DeepInfraFP8 $1.00 $2.70 $0.101M66K94.8%24h Cheapest
FeatherlessFP4 $1.00 $2.70 $0.10262K33K92.9%24h Cheapest

Value

Price vs. performance

4 models score higher for the same price or lesson SciCode, e.g. MiMo-V2.6-Pro.
27.8%40.8%53.9%66.9% $0.01$0.10$1.00$10.00 DeepSeek V4.1 Flash 1017 (DeepSeek) — 51.8% · $0.30/1M in Gemini 4 Argon (Google) — 61.8% · $2.00/1M in Claude Haiku 5.5 (Anthropic) — 55.0% · $0.10/1M in Mistral Large 4 (Mistral) — 54.2% · $0.68/1M in GPT-6.1 Sol (OpenAI) — 55.8% · $2.00/1M in Claude Sonnet 5.5 (Anthropic) — 61.0% · $2.00/1M in GPT-6 Luna (OpenAI) — 54.6% · $0.10/1M in GPT-6 Sol (OpenAI) — 57.6% · $2.00/1M in Claude Opus 5.5 (Anthropic) — 66.9% · $4.00/1M in MiMo-V2.6-Flash (Xiaomi) — 51.3% · $0.14/1M in MiMo-V2.6-Pro (Xiaomi) — 60.9% · $0.43/1M in Grok 4.7 (xAI) — 57.8% · $2.00/1M in DeepSeek V4.1 Flash (DeepSeek) — 51.8% · $0.056/1M in GPT-6 Astra (OpenAI) — 56.5% · $10.00/1M in Qwen3.8 Max (0902) (Qwen) — 53.2% · $2.00/1M in Muse Spark 1.3 (Meta) — 59.7% · $1.25/1M in Gemini 3.8 Flash (Google) — 56.6% · $0.82/1M in Claude Fable 5.1 (Anthropic) — 63.1% · $10.00/1M in GLM 5.3 Flash (Z.ai) — 51.6% · $0.047/1M in GLM 5.3 (Z.ai) — 59.0% · $0.079/1M in Qwen3.8 27B (Qwen) — 46.6% · $0.04/1M in Gemini 3.7 Flash (Google) — 59.8% · $0.75/1M in DeepSeek V4 Pro 0813 (DeepSeek) — 51.0% · $0.66/1M in Grok 4.6 (xAI) — 56.5% · $2.00/1M in Muse Spark 1.2 (Meta) — 57.4% · $1.25/1M in DeepSeek V4 Flash 0731 (DeepSeek) — 49.9% · $0.44/1M in Claude Opus 5 (Anthropic) — 56.4% · $5.00/1M in Gemini 3.6 Flash (Google) — 53.4% · $0.75/1M in Gemini 3.5 Flash Lite (Google) — 41.3% · $0.30/1M in Kimi K3 (Moonshot AI) — 59.5% · $0.24/1M in Muse Spark 1.1 (Meta) — 58.8% · $1.25/1M in GPT-5.6 Luna (OpenAI) — 53.6% · $0.20/1M in GPT-5.6 Terra (OpenAI) — 55.0% · $2.00/1M in GPT-5.6 Sol (OpenAI) — 57.8% · $4.00/1M in Grok 4.5 (xAI) — 55.0% · $2.00/1M in Claude Sonnet 5 (Anthropic) — 54.3% · $2.00/1M in GLM 5.2 (Z.ai) — 51.2% · $0.62/1M in Kimi K2.7 Code (Moonshot AI) — 47.8% · $0.67/1M in Claude Fable 5 (Anthropic) — 61.0% · $10.00/1M in Qwen3.7 Plus (Qwen) — 46.1% · $0.32/1M in MiniMax M3 (MiniMax) — 47.1% · $0.30/1M in Claude Opus 4.8 (Anthropic) — 53.5% · $5.00/1M in Qwen3.7 Max (Qwen) — 49.5% · $1.48/1M in Grok Build 0.1 (xAI) — 50.2% · $1.00/1M in Gemini 3.5 Flash (Google) — 53.9% · $1.50/1M in Gemini 3.1 Flash Lite (Google) — 43.4% · $0.25/1M in Grok 4.3 (xAI) — 48.3% · $1.25/1M in Qwen3.6 35B A3B (Qwen) — 36.6% · $0.10/1M in Qwen3.6 27B (Qwen) — 37.3% · $0.25/1M in GPT-5.5 (OpenAI) — 56.1% · $5.00/1M in DeepSeek V4 Pro 0423 (DeepSeek) — 51.0% · $0.95/1M in DeepSeek V4 Flash 0423 (DeepSeek) — 49.9% · $0.091/1M in MiMo-V2.5-Pro (Xiaomi) — 50.2% · $0.43/1M in MiMo-V2.5 (Xiaomi) — 43.1% · $0.14/1M in Kimi K2.6 (Moonshot AI) — 53.5% · $0.65/1M in Claude Opus 4.7 (Anthropic) — 54.5% · $5.00/1M in GLM 5.1 (Z.ai) — 44.8% · $0.97/1M in Gemma 4 31B (Google) — 45.5% · $0.20/1M in Qwen3.6 Plus (Qwen) — 40.7% · $0.33/1M in MiniMax M2.7 (MiniMax) — 50.1% · $0.30/1M in GPT-5.4 Nano (OpenAI) — 47.2% · $0.20/1M in GPT-5.4 Mini (OpenAI) — 52.1% · $0.75/1M in Mistral Small 4 (Mistral) — 27.8% · $0.15/1M in Qwen3.5-9B (Qwen) — 29.5% · $0.10/1M in GPT-5.4 (OpenAI) — 56.6% · $2.50/1M in Gemini 3.1 Flash Lite Preview (Google) — 43.4% · $0.25/1M in Qwen3.5-35B-A3B (Qwen) — 29.3% · $0.15/1M in Qwen3.5-122B-A10B (Qwen) — 35.6% · $0.26/1M in Gemini 3.1 Pro Preview (Google) — 58.7% · $2.00/1M in Claude Sonnet 4.6 (Anthropic) — 46.8% · $3.00/1M in Qwen3 Coder Next (Qwen) — 36.2% · $0.12/1M in Kimi K2.5 (Moonshot AI) — 49.0% · $0.50/1M in GLM 4.7 (Z.ai) — 45.1% · $0.54/1M in Mistral Large 3 2512 (Mistral) — 36.6% · $0.50/1M in DeepSeek V3.2 (DeepSeek) — 38.9% · $0.28/1M in GPT-5.1 (OpenAI) — 43.3% · $1.25/1M in Claude Haiku 4.5 (Anthropic) — 42.3% · $1.00/1M in GLM 4.6 (Z.ai) — 38.4% · $0.55/1M in Claude Sonnet 4.5 (Anthropic) — 45.7% · $3.00/1M in DeepSeek V3.2 Exp (DeepSeek) — 38.9% · $0.27/1M in DeepSeek V3.1 Terminus (DeepSeek) — 38.0% · $0.27/1M in GPT-5 (OpenAI) — 42.9% · $1.25/1M in GPT-5 Mini (OpenAI) — 39.2% · $0.25/1M in gpt-oss-120b (OpenAI) — 36.0% · $0.15/1M in gpt-oss-20b (OpenAI) — 38.9% · $0.018/1M in Qwen3 235B A22B Thinking 2507 (Qwen) — 41.4% · $0.45/1M in Gemini 2.5 Pro (Google) — 46.3% · $1.25/1M in Gemini 2.5 Pro Preview 06-05 (Google) — 46.3% · $1.25/1M in R1 0528 (DeepSeek) — 38.3% · $0.50/1M in Qwen3 14B (Qwen) — 31.6% · $0.12/1M in Qwen3 32B (Qwen) — 35.4% · $0.08/1M in Step 3.7 Flash (StepFun) — 40.1% · $0.20/1M in Step 5 Preview (StepFun) — 58.9% · $1.00/1M in Step 5 Preview

Step 5 Preview Other StepFun Other labs Value frontier · SciCode vs. input price per 1M tokens (log scale) · Drag to pan, pinch or Ctrl + scroll to zoom, double-click to zoom in.

Benchmarks

4 benchmark scores

BenchmarkScoreRankLeader
SciCodeSoftware engineering · Research-coding problems from the natural sciences 58.9% #11of 93 Claude Opus 5.566.9%
WebDev ArenaDesign & visual · People vote on which model builds the better website (Elo) 1570 #29of 88 Claude Opus 5.51820
CritPtReasoning & knowledge · Open-ended, research-level physics problems 20.9% #20of 96 GPT-5.6 Sol32.3%
ProofBenchMaths · Graduate maths proofs verified in Lean 4 42.0% #39of 70 Claude Sonnet 5.5100.0%

Specs

Details

Model ID
stepfun/step-5-preview
Developer
StepFun
Release date
Oct 8, 2026 ·
Context window
1,048,576 tokens
Max output
64,000 tokens
API price
$1.00 / $2.70 per 1M input / output tokens
Providers
4
Input types
text, image, video
Reasoning
Yes
Tool calling
Yes
Open weights
Yes
Free tier
No

Release date, prices and providers from OpenRouter's catalog; buying directly from a provider can cost a little differently. Uptime is the share of OpenRouter requests each provider served over the last day. Benchmark scores are the best result per benchmark from Epoch AI, licensed CC BY 4.0. Rank counts every model tracked here with a score.