Last verified 2025-09-22 (left) · 2025-09-22 (right)
Claude Opus 4.1 (Legacy) vs Gemini 2.5 Flash — Pricing & Capability Comparison
Claude Opus 4.1 (Legacy) charges $15.00 per million input tokens and $75.00 per million output tokens. Gemini 2.5 Flash comes in at $0.30 / $2.50. Context windows span 200K vs 1M tokens respectively.
TL;DR — Quick Comparison
- ✓Gemini 2.5 Flash is cheaper overall: $2.80 per 1M tokens (in+out) vs $90.00 for Claude Opus 4.1 (Legacy) — saves $87.20 per 1M tokens
- ✓Input pricing: Claude Opus 4.1 (Legacy) $15.00/1M vs Gemini 2.5 Flash $0.30/1M
- ✓Output pricing: Claude Opus 4.1 (Legacy) $75.00/1M vs Gemini 2.5 Flash $2.50/1M
- ✓Context window: Gemini 2.5 Flash offers more (1M 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
Gemini 2.5 Flash
$0.30
Gemini 2.5 Flash leads here
Output price (per 1M)
Claude Opus 4.1 (Legacy)
$75.00
Gemini 2.5 Flash
$2.50
Gemini 2.5 Flash leads here
Context window
Claude Opus 4.1 (Legacy)
200,000 tokens
Gemini 2.5 Flash
1,000,000 tokens
Gemini 2.5 Flash leads here
Cached input
Claude Opus 4.1 (Legacy)
Not published
Gemini 2.5 Flash
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.
| Scenario | Claude Opus 4.1 (Legacy) | Gemini 2.5 Flash |
|---|---|---|
Balanced conversation 50% input · 50% output | $0.450 | $0.0140 |
Input-heavy workflow 80% input · 20% output | $0.270 | $0.0074 |
Generation heavy 30% input · 70% output | $0.570 | $0.0184 |
Cached system prompt 90% cached input · 10% fresh output | $0.210 | $0.0052 |
Frequently asked questions
Which is cheaper: Claude Opus 4.1 (Legacy) or Gemini 2.5 Flash?
Gemini 2.5 Flash is cheaper for input tokens at $0.30 per 1M tokens compared to $15.00. For output, Gemini 2.5 Flash costs $2.50 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 Gemini 2.5 Flash?
Gemini 2.5 Flash pricing: $0.30 per 1M input tokens and $2.50 per 1M output tokens. Context window: 1,000,000 tokens.
How much does it cost per 1K tokens?
Per 1K tokens: Claude Opus 4.1 (Legacy) costs $0.0150 input / $0.0750 output. Gemini 2.5 Flash costs $0.0003 input / $0.0025 output. This is useful for calculating small-scale usage costs.
Which model supports a larger context window?
Gemini 2.5 Flash offers 1,000,000 tokens (1M) versus 200K for Claude Opus 4.1 (Legacy).
What is the estimated monthly cost for typical usage?
For a typical workload of 10M input + 2M output tokens per month: Claude Opus 4.1 (Legacy) would cost approximately $300.00, while Gemini 2.5 Flash would cost $8.00. Gemini 2.5 Flash is more economical for this usage pattern.
Do these models support prompt caching?
Claude Opus 4.1 (Legacy) does not publish cached pricing. Gemini 2.5 Flash does not publish cached pricing.
Which model is best for my use case?
Choose Gemini 2.5 Flash for cost-sensitive applications with high input volume. Choose Gemini 2.5 Flash if you need 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.