Standard Compute
Model comparison 2026

Claude Opus 5.5 vs Step 5 Preview

Claude Opus 5.5
Anthropic · Frontier · Proprietary
$8.80/1M · 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
Opus 5.5
Step 5
Maker
Anthropic
StepFun
Blended price / 1M
$8.80
$1.51
Input / output
$4.00 in · $20 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
10.0
8.2
Agentic Ability
10.0
7.6
Speed
7.6
7.5
Value for money
5.7
7.1
Reliability
9.5
8.6

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

Verdict: Opus 5.5 or Step 5?

Updated 2026-10-13

Choose Claude Opus 5.5 if you want the hardest coding and agent steps, with Sonnet 5.5 handling routine work. 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 Opus 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 Opus 5.5 runs about $8.80 per 1M tokens (blended) and is proprietary; Step 5 Preview is about $1.51 and proprietary.

Where Opus 5.5 falls short
  • Costs twice Sonnet 5.5 per request ($0.107 vs $0.053) for a small measured gain
  • Sonnet 5.5 scores higher in Artificial Analysis's Terminal-Bench 4.0 run (63.6% vs 59.6%)
Full Opus 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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