Standard Compute
Model comparison 2026

GPT-5.3-Codex vs Step 5 Preview

GPT-5.3-Codex
OpenAI · Balanced · Proprietary
$5.42/1M · 400K 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
GPT-5.3-Codex
Step 5
Maker
OpenAI
StepFun
Blended price / 1M
$5.42
$1.51
Input / output
$1.75 in · $14 out / 1M tokens
$1.00 in · $2.70 out / 1M tokens
Context window
400K
1M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
6.8
8.2
Agentic Ability
5.1
7.6
Speed
8.0
7.5
Value for money
5.0
7.1
Reliability
8.4
8.6

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

Verdict: GPT-5.3-Codex or Step 5?

Updated 2026-10-13

Choose GPT-5.3-Codex if you want existing Codex setups on an API key that still pin GPT-5.3-Codex. Choose Step 5 Preview if you want mid-priced agent loops that want more capability than a Flash-class model.

In our editorial scoring, Step 5 Preview leads in 4 of five dimensions (output quality, agentic ability, value for money and reliability), while GPT-5.3-Codex leads in 1. On price, GPT-5.3-Codex runs about $5.42 per 1M tokens (blended) and is proprietary; Step 5 Preview is about $1.51 and proprietary.

Where GPT-5.3-Codex falls short
  • Deprecated in Codex with ChatGPT sign-in
  • GPT-6.1 Sol scores far higher for about 20% more per request ($0.067 vs $0.055)
Full GPT-5.3-Codex 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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