Last verified 2026-02-11 (left) · 2026-03-06 (right)
Claude Opus 4.5 (Legacy) vs GPT-5.4 Pro — Pricing & Capability Comparison
Claude Opus 4.5 (Legacy) charges $5.00 per million input tokens and $25.00 per million output tokens. GPT-5.4 Pro comes in at $30.00 / $180.00. Context windows span 200K vs 1.1M tokens respectively.
TL;DR — Quick Comparison
- ✓Claude Opus 4.5 (Legacy) is cheaper overall: $30.00 per 1M tokens (in+out) vs $210.00 for GPT-5.4 Pro — saves $180.00 per 1M tokens
- ✓Input pricing: Claude Opus 4.5 (Legacy) $5.00/1M vs GPT-5.4 Pro $30.00/1M
- ✓Output pricing: Claude Opus 4.5 (Legacy) $25.00/1M vs GPT-5.4 Pro $180.00/1M
- ✓Context window: GPT-5.4 Pro offers more (1.1M vs 200K)
- ✓Use our calculator below to estimate costs for your specific usage pattern
Input price (per 1M)
Claude Opus 4.5 (Legacy)
$5.00
GPT-5.4 Pro
$30.00
Claude Opus 4.5 (Legacy) leads here
Output price (per 1M)
Claude Opus 4.5 (Legacy)
$25.00
GPT-5.4 Pro
$180.00
Claude Opus 4.5 (Legacy) leads here
Context window
Claude Opus 4.5 (Legacy)
200,000 tokens
GPT-5.4 Pro
1,050,000 tokens
GPT-5.4 Pro leads here
Cached input
Claude Opus 4.5 (Legacy)
$0.500
GPT-5.4 Pro
Not published
Claude Opus 4.5 (Legacy) leads here
Cost comparison for 10K-token workloads
Side-by-side pricing for identical workloads (10,000 total tokens per request) across different distributions.
| Scenario | Claude Opus 4.5 (Legacy) | GPT-5.4 Pro | Claude Opus 4.5 (Legacy) cached |
|---|---|---|---|
Balanced conversation 50% input · 50% output | $0.150 | $1.05 | $0.128 |
Input-heavy workflow 80% input · 20% output | $0.0900 | $0.600 | $0.0540 |
Generation heavy 30% input · 70% output | $0.190 | $1.35 | $0.177 |
Cached system prompt 90% cached input · 10% fresh output | $0.0700 | $0.450 | $0.0295 |
Frequently asked questions
Which is cheaper: Claude Opus 4.5 (Legacy) or GPT-5.4 Pro?
Claude Opus 4.5 (Legacy) is cheaper for input tokens at $5.00 per 1M tokens compared to $30.00. For output, Claude Opus 4.5 (Legacy) costs $25.00 per 1M tokens versus $180.00 for GPT-5.4 Pro.
What is the cost per 1M tokens for Claude Opus 4.5 (Legacy)?
Claude Opus 4.5 (Legacy) pricing: $5.00 per 1M input tokens and $25.00 per 1M output tokens. Context window: 200,000 tokens.
What is the cost per 1M tokens for GPT-5.4 Pro?
GPT-5.4 Pro pricing: $30.00 per 1M input tokens and $180.00 per 1M output tokens. Context window: 1,050,000 tokens.
How much does it cost per 1K tokens?
Per 1K tokens: Claude Opus 4.5 (Legacy) costs $0.0050 input / $0.0250 output. GPT-5.4 Pro costs $0.0300 input / $0.1800 output. This is useful for calculating small-scale usage costs.
Which model supports a larger context window?
GPT-5.4 Pro offers 1,050,000 tokens (1.1M) versus 200K for Claude Opus 4.5 (Legacy).
What is the estimated monthly cost for typical usage?
For a typical workload of 10M input + 2M output tokens per month: Claude Opus 4.5 (Legacy) would cost approximately $100.00, while GPT-5.4 Pro would cost $660.00. Claude Opus 4.5 (Legacy) is more economical for this usage pattern.
Do these models support prompt caching?
Claude Opus 4.5 (Legacy) supports prompt caching at $0.500 per 1M cached tokens, reducing costs for repeated context by up to 90%. GPT-5.4 Pro does not publish cached pricing.
Which model is best for my use case?
Choose Claude Opus 4.5 (Legacy) for cost-sensitive applications with high input volume. Choose GPT-5.4 Pro if you need 1.1M context for long documents or conversations. Consider prompt caching if you have repeated context. Use our token calculator to model your specific usage pattern.