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

Claude Opus 4.1 (Legacy) vs o3 — Pricing & Capability Comparison

Claude Opus 4.1 (Legacy) charges $15.00 per million input tokens and $75.00 per million output tokens. o3 comes in at $2.00 / $8.00. Context windows span 200K vs 200K tokens respectively.

TL;DR — Quick Comparison

  • o3 is cheaper overall: $10.00 per 1M tokens (in+out) vs $90.00 for Claude Opus 4.1 (Legacy) — saves $80.00 per 1M tokens
  • Input pricing: Claude Opus 4.1 (Legacy) $15.00/1M vs o3 $2.00/1M
  • Output pricing: Claude Opus 4.1 (Legacy) $75.00/1M vs o3 $8.00/1M
  • Context window: Claude Opus 4.1 (Legacy) offers more (200K vs 200K)
  • Use our calculator below to estimate costs for your specific usage pattern

Input price (per 1M)

Claude Opus 4.1 (Legacy)

$15.00

o3

$2.00

o3 leads here

Output price (per 1M)

Claude Opus 4.1 (Legacy)

$75.00

o3

$8.00

o3 leads here

Context window

Claude Opus 4.1 (Legacy)

200,000 tokens

o3

200,000 tokens

Claude Opus 4.1 (Legacy) leads here

Cached input

Claude Opus 4.1 (Legacy)

Not published

o3

Not published

No published data

Cost comparison for 10K-token workloads

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

ScenarioClaude Opus 4.1 (Legacy)o3
Balanced conversation
50% input · 50% output
$0.450$0.0500
Input-heavy workflow
80% input · 20% output
$0.270$0.0320
Generation heavy
30% input · 70% output
$0.570$0.0620
Cached system prompt
90% cached input · 10% fresh output
$0.210$0.0260

Frequently asked questions

Which is cheaper: Claude Opus 4.1 (Legacy) or o3?

o3 is cheaper for input tokens at $2.00 per 1M tokens compared to $15.00. For output, o3 costs $8.00 per 1M tokens versus $75.00 for Claude Opus 4.1 (Legacy).

What is the cost per 1M tokens for Claude Opus 4.1 (Legacy)?

Claude Opus 4.1 (Legacy) pricing: $15.00 per 1M input tokens and $75.00 per 1M output tokens. Context window: 200,000 tokens.

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.

How much does it cost per 1K tokens?

Per 1K tokens: Claude Opus 4.1 (Legacy) costs $0.0150 input / $0.0750 output. o3 costs $0.0020 input / $0.0080 output. This is useful for calculating small-scale usage costs.

Which model supports a larger context window?

Claude Opus 4.1 (Legacy) offers 200,000 tokens (200K) versus 200K for o3.

What is the estimated monthly cost for typical usage?

For a typical workload of 10M input + 2M output tokens per month: Claude Opus 4.1 (Legacy) would cost approximately $300.00, while o3 would cost $36.00. o3 is more economical for this usage pattern.

Do these models support prompt caching?

Claude Opus 4.1 (Legacy) does not publish cached pricing. o3 does not publish cached pricing.

Which model is best for my use case?

Choose o3 for cost-sensitive applications with high input volume. Choose Claude Opus 4.1 (Legacy) 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.

Related resources

Claude Opus 4.1 (Legacy) vs o3 Pricing (2025) — Cost per 1M Tokens Comparison | LLM Practical Experience Hub