GPT-5.3 Codex vs o4-mini

Compare OpenAI and OpenAI AI models

OpenAI

GPT-5.3 Codex

OpenAI

o4-mini

Try OpenAI →

Cost Comparison (1000 input + 500 output tokens, 100 requests/day)

GPT-5.3 Codex

Per Request:$0.008750

Daily:$0.875

Monthly:$26.25

Yearly:$319.375

o4-mini

Per Request:$0.003300

Daily:$0.33

Monthly:$9.90

Yearly:$120.45

Cost Differences

$0.005450

Per Request

$0.545

Daily

$16.35

Monthly

$198.925

Yearly

o4-mini costs less than GPT-5.3 Codex

Feature Comparison

Feature	GPT-5.3 Codex	o4-mini
Provider	OpenAI	OpenAI
Input Price	$1.75/1M tokens	$1.10/1M tokens
Output Price	$14.00/1M tokens	$4.40/1M tokens
Context Window	256,000 tokens	2,000,000 tokens
Max Output	32,768 tokens	131,072 tokens
Category	coding	reasoning
Capabilities	textcode	textreasoningcode
Release Date	3/1/2026	4/16/2025

GPT-5.3 Codex vs o4-mini: Which Should You Choose?

Choosing between GPT-5.3 Codex and o4-mini depends on your priorities: cost efficiency, context length, or raw capability. o4-mini is the more affordable option at $1.10/1M input tokens — 37% cheaper than GPT-5.3 Codex. Meanwhile, o4-mini offers a significantly larger context window at 2,000,000 tokens vs 256,000 for GPT-5.3 Codex.

These models target different tiers: GPT-5.3 Codex is a coding model while o4-mini is reasoning. This means they're optimized for different workloads. o4-mini targets more demanding workloads, while GPT-5.3 Codex provides a cost-effective option for everyday tasks.

Output costs matter too. GPT-5.3 Codex charges $14.00/1M output tokens vs $4.40 for o4-mini. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. o4-mini has the edge here at $4.40/1M output tokens.

Best Use Cases

Choose GPT-5.3 Codex when:

• You're already using OpenAI's API ecosystem

Choose o4-mini when:

• Budget is a primary concern
• You need a larger context window (2,000,000 tokens)
• You need more capabilities (reasoning)
• You need longer outputs (up to 131,072 tokens)
• You're already using OpenAI's API ecosystem

Try Different Scenarios

Use the calculator below to see how costs change with different usage patterns

GPT-5.3 Codex (OpenAI)

Cost Calculator

Provider

Model

Input Tokens

Output Tokens

Requests/Day

Select a provider and model to see costs

o4-mini (OpenAI)

Cost Calculator

Provider

Model

Input Tokens

Output Tokens

Requests/Day

Select a provider and model to see costs

Start using GPT-5.3 Codex today

Start using o4-mini today

Frequently Asked Questions

Which is cheaper, GPT-5.3 Codex or o4-mini?▼

o4-mini is cheaper for input tokens at $1.10 per million tokens vs $1.75 for GPT-5.3 Codex — that's 37% savings on input costs.

What is the context window difference between GPT-5.3 Codex and o4-mini?▼

GPT-5.3 Codex supports 256,000 tokens while o4-mini supports 2,000,000 tokens — a difference of 1,744,000 tokens in favor of o4-mini.

Which model is better for AI Chatbot?▼

Both models support text. For ai chatbot, o4-mini is the lower-cost option, while o4-mini offers a larger context window (2,000,000 vs 256,000 tokens). Choose o4-mini for budget sensitivity or o4-mini for longer context tasks.

Which model has better overall pricing for heavy usage?▼

At 100 requests/day with 1,000 input and 500 output tokens each, GPT-5.3 Codex costs about $26.25/month and o4-mini costs about $9.90/month. Overall, o4-mini has lower combined input + output rates ($1.10 in, $4.40 out) vs GPT-5.3 Codex.