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GPT-5.3 Codex vs o4-mini

GPT-5.3 Codex vs o4-mini: o4-mini is cheaper for input-heavy usage ($1.10/M vs $1.75/M input tokens), while o4-mini is better for long-context tasks (2,000,000 tokens).

Direct answer: choose o4-mini for lower token spend and choose o4-mini when your workload needs longer context.

Compare input and output token pricing, context windows, and monthly cost estimates on one page so you can pick the cheaper model fast.

OpenAI
GPT-5.3 Codex
vs
OpenAI
o4-mini

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

Quick Recommendation

Winner for direct API pricing: o4-mini. At the default workload, o4-mini saves about $16.35/month ($198.925/year) versus GPT-5.3 Codex.

Feature Comparison

FeatureGPT-5.3 Codexo4-mini
ProviderOpenAIOpenAI
Input Price$1.75/1M tokens$1.10/1M tokens
Output Price$14.00/1M tokens$4.40/1M tokens
Context Window256,000 tokens2,000,000 tokens
Max Output32,768 tokens131,072 tokens
Categorycodingreasoning
Capabilities
textcode
textreasoningcode
Release Date3/1/20264/16/2025

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 tokens37% 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

Pros and Caveats at a Glance

GPT-5.3 Codex

  • Input pricing: $1.75/M tokens
  • Output pricing: $14.00/M tokens
  • Context window: 256,000 tokens
  • Max output: 32,768 tokens

Watch out for

  • Higher input cost than o4-mini
  • Higher output cost than o4-mini
  • Smaller context window than o4-mini

o4-mini

  • Input pricing: $1.10/M tokens
  • Output pricing: $4.40/M tokens
  • Context window: 2,000,000 tokens
  • Max output: 131,072 tokens

Watch out for

  • Trade-offs are minor in this matchup.

Try Different Scenarios

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

GPT-5.3 Codex (OpenAI)

o4-mini (OpenAI)

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Start using o4-mini today

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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.

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