Standard Compute
Model comparison 2026

Gemini 3.8 Flash vs GPT-5.3-Codex

Gemini 3.8 Flash
Google · Balanced · Proprietary
$1.65/1M · 1.0M ctx
GPT-5.3-Codex
OpenAI · Balanced · Proprietary
$5.42/1M · 400K 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
Gemini 3.8 Flash
GPT-5.3-Codex
Maker
Google
OpenAI
Blended price / 1M
$1.65
$5.42
Input / output
$0.75 in · $3.75 out / 1M tokens
$1.75 in · $14 out / 1M tokens
Context window
1.0M
400K
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.1
8.8
Agentic Ability
8.9
9.3
Speed
9.2
7.8
Value for money
8.8
7.8
Reliability
8.9
8.7

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

Verdict: Gemini 3.8 Flash or GPT-5.3-Codex?

Updated 2026-10-13

Choose Gemini 3.8 Flash if you want high-throughput agents and Gemini CLI users who want speed and big context. Choose GPT-5.3-Codex if you want codex CLI users and dedicated coding agents.

In our editorial scoring, Gemini 3.8 Flash leads in 4 of five dimensions (output quality, speed, value for money and reliability), while GPT-5.3-Codex leads in 1. On price, Gemini 3.8 Flash runs about $1.65 per 1M tokens (blended) and is proprietary; GPT-5.3-Codex is about $5.42 and proprietary.

Where Gemini 3.8 Flash falls short
  • Price doubles to $1.50/$7.50 on January 1, 2027
  • Weak on long terminal tasks (19.1% on Terminal-Bench 4.0)
Full Gemini 3.8 Flash 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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