Last verified 2025-09-22 (left) · 2025-09-22 (right)

o3 vs o4-mini — Pricing & Capability Comparison

o3 charges $2.00 per million input tokens and $8.00 per million output tokens. o4-mini comes in at $1.10 / $4.40. Context windows span 200K vs 200K tokens respectively.

TL;DR — Quick Comparison

✓o4-mini is cheaper overall: $5.50 per 1M tokens (in+out) vs $10.00 for o3 — saves $4.50 per 1M tokens
✓Input pricing: o3 $2.00/1M vs o4-mini $1.10/1M
✓Output pricing: o3 $8.00/1M vs o4-mini $4.40/1M
✓Context window: o3 offers more (200K vs 200K)
✓Use our calculator below to estimate costs for your specific usage pattern

Input price (per 1M)

$2.00

o4-mini

$1.10

o4-mini leads here

Output price (per 1M)

$8.00

o4-mini

$4.40

o4-mini leads here

Context window

200,000 tokens

o4-mini

200,000 tokens

o3 leads here

Cached input

Not published

o4-mini

Not published

No published data

Which one should you choose?

Skip the spreadsheet if you just need the practical takeaway. Use these rules when deciding between o3 and o4-mini.

Choose o4-mini if input tokens dominate your bill

o4-mini has the lower input rate, which usually matters most for chat, RAG, classification, and long-prompt workflows where prompt volume stays much larger than generated output.

Choose o4-mini if you generate long answers

o4-mini is cheaper on output tokens, so it tends to win for report generation, coding assistance, reasoning traces, and any workflow where completions are long.

Choose o3 if context size is the blocker

o3 offers the larger published context window, which is more important than small pricing differences when you need to fit large files, long chats, or multi-document prompts into one request.

Cost comparison for 10K-token workloads

Side-by-side pricing for identical workloads (10,000 total tokens per request) across different distributions.

Scenario	o3	o4-mini
Balanced conversation 50% input · 50% output	$0.0500	$0.0275
Input-heavy workflow 80% input · 20% output	$0.0320	$0.0176
Generation heavy 30% input · 70% output	$0.0620	$0.0341
Cached system prompt 90% cached input · 10% fresh output	$0.0260	$0.0143

Frequently asked questions

Which is cheaper: o3 or o4-mini?

o4-mini is cheaper for input tokens at $1.10 per 1M tokens compared to $2.00. For output, o4-mini costs $4.40 per 1M tokens versus $8.00 for o3.

What is the cost per 1M tokens for o3?

o3 pricing: $2.00 per 1M input tokens and $8.00 per 1M output tokens. Context window: 200,000 tokens.

What is the cost per 1M tokens for o4-mini?

o4-mini pricing: $1.10 per 1M input tokens and $4.40 per 1M output tokens. Context window: 200,000 tokens.

How much does it cost per 1K tokens?

Per 1K tokens: o3 costs $0.0020 input / $0.0080 output. o4-mini costs $0.0011 input / $0.0044 output. This is useful for calculating small-scale usage costs.

Which model supports a larger context window?

o3 offers 200,000 tokens (200K) versus 200K for o4-mini.

What is the estimated monthly cost for typical usage?

For a typical workload of 10M input + 2M output tokens per month: o3 would cost approximately $36.00, while o4-mini would cost $19.80. o4-mini is more economical for this usage pattern.

Do these models support prompt caching?

o3 does not publish cached pricing. o4-mini does not publish cached pricing.

Which model is best for my use case?

Choose o4-mini for cost-sensitive applications with high input volume. Choose o3 if you need 200K context for long documents or conversations. Consider prompt caching if you have repeated context. Use our token calculator to model your specific usage pattern.