Model Comparison

Claude Opus 4.5 vs Mercury 2Which is better in 2026?

Claude Opus 4.5 significantly outperforms across most benchmarks. Mercury 2 is 26.7x cheaper per token.

Verdict: Claude Opus 4.5 vs Mercury 2 — which is better?

Claude Opus 4.5 (by Anthropic) and Mercury 2 (by Inception) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude Opus 4.5 outperforms in 1 benchmarks (GPQA), while Mercury 2 is better at 0 benchmarks. Claude Opus 4.5 significantly outperforms across most benchmarks.

On price, Mercury 2 is roughly 26.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 4.5 also accepts a larger context window (200,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude Opus 4.5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you process long inputs — it offers a 200,000 token context window

Choose Mercury 2 if…

  • cost matters — it's about 26.7x cheaper per token
  • you want the most recent training data — it shipped Feb 2026
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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Opus 4.5 outperforms in 1 benchmarks (GPQA), while Mercury 2 is better at 0 benchmarks.

Claude Opus 4.5 significantly outperforms across most benchmarks.

Wed Jun 10 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Mercury 2 costs less

For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 20.0x more expensive than Mercury 2 ($0.25/1M tokens).

For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 33.3x more expensive than Mercury 2 ($0.75/1M tokens).

In conclusion, Claude Opus 4.5 is more expensive than Mercury 2.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Wed Jun 10 2026 • llm-stats.com
Anthropic
Claude Opus 4.5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
Inception
Mercury 2
Input tokens$0.25
Output tokens$0.75
Best providerInception
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Context Window

Maximum input and output token capacity

Claude Opus 4.5 accepts 200,000 input tokens compared to Mercury 2's 128,000 tokens. Claude Opus 4.5 can generate longer responses up to 64,000 tokens, while Mercury 2 is limited to 8,192 tokens.

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
Inception
Mercury 2
Input128,000 tokens
Output8,192 tokens
Wed Jun 10 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Opus 4.5 supports multimodal inputs, whereas Mercury 2 does not.

Claude Opus 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 4.5

Text
Images
Audio
Video

Mercury 2

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 4.5

Proprietary

Closed source

Mercury 2

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while Mercury 2 was released on 2026-02-24.

Mercury 2 is 3 months newer than Claude Opus 4.5.

Claude Opus 4.5

Nov 24, 2025

6 months ago

Mercury 2

Feb 24, 2026

3 months ago

3mo newer

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a documented knowledge cutoff of 2025-03-31, while Mercury 2's cutoff date is not specified.

We can confirm Claude Opus 4.5's training data extends to 2025-03-31, but cannot make a direct comparison without Mercury 2's cutoff date.

Claude Opus 4.5

Mar 2025

Mercury 2

—

Provider Availability

Claude Opus 4.5 is available from Anthropic. Mercury 2 is available from Inception.

Claude Opus 4.5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

Mercury 2

inception logo
Inception
Input Price:Input: $0.25/1MOutput Price:Output: $0.75/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Anthropic
Larger context window (200,000 tokens)
Supports multimodal inputs
Higher GPQA score (87.0% vs 74.0%)
Inception
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.5
Inception
Mercury 2

FAQ

Common questions about Claude Opus 4.5 vs Mercury 2.

Which is better, Claude Opus 4.5 or Mercury 2?

Claude Opus 4.5 significantly outperforms across most benchmarks. Claude Opus 4.5 is made by Anthropic and Mercury 2 is made by Inception. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 4.5 compare to Mercury 2 in benchmarks?

Claude Opus 4.5 scores Tau2 Telecom: 98.2%, MMMLU: 90.8%, Tau2 Retail: 88.9%, GPQA: 87.0%, SWE-Bench Verified: 80.9%. Mercury 2 scores AIME 2025: 91.1%, GPQA: 74.0%, IFBench: 71.0%, LiveCodeBench: 67.0%, Tau2 Airline: 53.0%.

Is Claude Opus 4.5 cheaper than Mercury 2?

Mercury 2 is 20.0x cheaper for input tokens. Claude Opus 4.5 costs $5.00/M input and $25.00/M output via anthropic. Mercury 2 costs $0.25/M input and $0.75/M output via inception.

What are the context window sizes for Claude Opus 4.5 and Mercury 2?

Claude Opus 4.5 supports 200K tokens and Mercury 2 supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 4.5 and Mercury 2?

Key differences include context window (200K vs 128K), input pricing ($5.00 vs $0.25/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and Mercury 2?

Claude Opus 4.5 is developed by Anthropic and Mercury 2 is developed by Inception.

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