Standard Compute
Model Comparison 2026

GPT-5.3-Codex vs GPT-5.6 Terra

GPT-5.3-Codex
OpenAI · Balanced · Proprietary
$5.42/1M · 400K ctx
GPT-5.6 Terra
OpenAI · Balanced · Proprietary
$3.13/1M · 1.1M ctx

Community Vote

Pick a winner in each dimension — change your vote anytime. 1 votes cast so far.

Output Quality
Correctness and depth of what it produces
GPT-5.3-Codex 100%0% Terra
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
GPT-5.3-Codex
Terra
Maker
OpenAI
OpenAI
Blended price / 1M
$5.42
$3.13
Input / output
$1.75 in · $14 out / 1M tokens
$1.25 in · $7.50 out / 1M tokens
Context window
400K
1.1M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
8.8
9.0
Agentic Ability
9.3
9.0
Speed
7.8
8.4
Value for $
7.8
8.8
Reliability
8.7
9.2

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

Verdict: GPT-5.3-Codex or Terra?

Updated 2026-08-02

Choose GPT-5.3-Codex if you want codex CLI users and dedicated coding agents. Choose GPT-5.6 Terra if you want the everyday OpenAI default for agents — volume work with frontier-adjacent quality.

In our editorial scoring, GPT-5.6 Terra leads in 4 of five dimensions (output quality, speed, value for $ 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; GPT-5.6 Terra is about $3.13 and proprietary.

Across 1 community votes on this matchup, GPT-5.3-Codex currently leads in 1 of five dimensions. Cast your own vote above to move the needle.

Where GPT-5.3-Codex falls short
  • Narrower than a general flagship outside coding
  • Mid-tier pricing
Full GPT-5.3-Codex breakdown →
Where Terra falls short
  • Steps behind Sol on the hardest tasks
  • Very new — long-run agent behavior still being characterized
Full Terra breakdown →

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