Model Comparison 2026

Claude Sonnet 4.6 vs GPT-5.3-Codex

Claude Sonnet 4.6
Anthropic · Balanced · Proprietary
$6.60/1M · 1M ctx
GPT-5.3-Codex
OpenAI · Balanced · Proprietary
$5.42/1M · 400K ctx

Community Vote

Pick a winner in each dimension — change your vote anytime.

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 $
How much capability you get per dollar
Reliability
Consistent results — fewer refusals, loops, and format breaks

Specs & Pricing, Side by Side

Spec
Sonnet 4.6
GPT-5.3-Codex
Maker
Anthropic
OpenAI
Blended price / 1M
$6.60
$5.42
Input / output
$3.00 in · $15 out / 1M tokens
$1.75 in · $14 out / 1M tokens
Context window
1M
400K
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.1
8.8
Agentic Ability
9.2
9.3
Speed
8.0
7.8
Value for $
8.0
7.8
Reliability
9.4
8.7

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

Verdict: Sonnet 4.6 or GPT-5.3-Codex?

Updated 2026-06-22

Choose Claude Sonnet 4.6 if you want the everyday agent default — strong quality without the flagship price. Choose GPT-5.3-Codex if you want codex CLI users and dedicated coding agents.

In our editorial scoring, Claude Sonnet 4.6 leads in 4 of five dimensions (output quality, speed, value for $ and reliability), while GPT-5.3-Codex leads in 1. On price, Claude Sonnet 4.6 runs about $6.60 per 1M tokens (blended) and is proprietary; GPT-5.3-Codex is about $5.42 and proprietary.

Where Sonnet 4.6 falls short
  • Still steps behind Opus on the very hardest tasks
  • Pricier than open-weight models of similar quality
Full Sonnet 4.6 breakdown →
Where GPT-5.3-Codex falls short
  • Narrower than a general flagship outside coding
  • Mid-tier pricing
Full GPT-5.3-Codex breakdown →

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