Standard Compute
Model comparison 2026

Claude Sonnet 5.5 vs Step 5 Preview

Claude Sonnet 5.5
Anthropic · Balanced · Proprietary
$4.40/1M · 1M ctx
Step 5 Preview
StepFun · Balanced · Proprietary
$1.51/1M · 1M ctx

Community vote

Pick a winner in each dimension. You can change your vote any time.

Output Quality
Correctness and depth of what it produces
Agentic Ability
Tool calls, instruction-following, and multi-step tasks
Speed
Tokens per second and time-to-first-token
Value for money
How much capability you get per dollar
Reliability
Consistent results: fewer refusals, loops and format breaks

Specs and pricing side by side

Spec
Sonnet 5.5
Step 5
Maker
Anthropic
StepFun
Blended price / 1M
$4.40
$1.51
Input / output
$2.00 in · $10 out / 1M tokens
$1.00 in · $2.70 out / 1M tokens
Context window
1M
1M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.8
8.2
Agentic Ability
9.7
7.6
Speed
8.4
7.5
Value for money
6.7
7.1
Reliability
9.4
8.6

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: Sonnet 5.5 or Step 5?

Updated 2026-10-13

Choose Claude Sonnet 5.5 if you want the everyday default for coding agents, escalating to Opus 5.5 for the hardest tasks. Choose Step 5 Preview if you want mid-priced agent loops that want more capability than a Flash-class model.

In our editorial scoring, Claude Sonnet 5.5 leads in 4 of five dimensions (output quality, agentic ability, speed and reliability), while Step 5 Preview leads in 1. On price, Claude Sonnet 5.5 runs about $4.40 per 1M tokens (blended) and is proprietary; Step 5 Preview is about $1.51 and proprietary.

Where Sonnet 5.5 falls short
  • Artificial Analysis flags it as very verbose, which adds output tokens
  • A cache miss bills input at $2 per million, 20 times the cache-read rate
Full Sonnet 5.5 breakdown →
Where Step 5 falls short
  • Still a preview, so behavior and price can change
  • Only StepFun serves it on OpenRouter, so there is no provider fallback
Full Step 5 breakdown →

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Current Claude, GPT, Gemini and open models are included with Standard Compute

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Current frontier models Claude Opus 5.5 · Claude Sonnet 5.5

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