Model Comparison

Claude Opus 5 vs Mercury 2Which is better in 2026?

Comparing Claude Opus 5 and Mercury 2 across benchmarks, pricing, and capabilities.

Verdict: Claude Opus 5 vs Mercury 2 — which is better?

Claude Opus 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.

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 5 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude Opus 5 if…

  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Choose Mercury 2 if…

  • cost matters — it's about 26.7x cheaper per token

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Claude Opus 5 and Mercury 2don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Mercury 2 costs less

For input processing, Claude Opus 5 ($5.00/1M tokens) is 20.0x more expensive than Mercury 2 ($0.25/1M tokens).

For output processing, Claude Opus 5 ($25.00/1M tokens) is 33.3x more expensive than Mercury 2 ($0.75/1M tokens).

In conclusion, Claude Opus 5 is more expensive than Mercury 2.*

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

Lowest available price from all providers
Mon Jul 27 2026 • llm-stats.com
Anthropic
Claude Opus 5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
Inception
Mercury 2
Input tokens$0.25
Output tokens$0.75
Best providerInception
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Opus 5 accepts 1,000,000 input tokens compared to Mercury 2's 128,000 tokens. Claude Opus 5 can generate longer responses up to 128,000 tokens, while Mercury 2 is limited to 8,192 tokens.

Anthropic
Claude Opus 5
Input1,000,000 tokens
Output128,000 tokens
Inception
Mercury 2
Input128,000 tokens
Output8,192 tokens
Mon Jul 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Opus 5 supports multimodal inputs, whereas Mercury 2 does not.

Claude Opus 5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 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 5

Proprietary

Closed source

Mercury 2

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5 was released on 2026-07-24, while Mercury 2 was released on 2026-02-24.

Claude Opus 5 is 5 months newer than Mercury 2.

Claude Opus 5

Jul 24, 2026

1 days ago

5mo newer
Mercury 2

Feb 24, 2026

5 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Opus 5 is available from Anthropic. Mercury 2 is available from Inception.

Claude Opus 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

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Larger context window (1,000,000 tokens)
Supports multimodal inputs
Inception
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Opus 5 and Mercury 2 side-by-side, then vote on the output you prefer.

Claude Opus 5
✓ Preferred
Mercury 2
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Opus 5
Inception
Mercury 2

FAQ

Common questions about Claude Opus 5 vs Mercury 2.

Which is better, Claude Opus 5 or Mercury 2?

Claude Opus 5 (Anthropic) and Mercury 2 (Inception) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Claude Opus 5 compare to Mercury 2 in benchmarks?

Claude Opus 5 scores BrowseComp: 90.8%, BioMysteryBench: 90.1%, OSWorld 2.0: 70.6%, DeepSWE 1.1: 68.8%, Humanity's Last Exam: 64.7%. Mercury 2 scores AIME 2025: 91.1%, GPQA: 74.0%, IFBench: 71.0%, LiveCodeBench: 67.0%, Tau2 Airline: 53.0%.

Is Claude Opus 5 cheaper than Mercury 2?

Mercury 2 is 20.0x cheaper for input tokens. Claude Opus 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 5 and Mercury 2?

Claude Opus 5 supports 1.0M 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 5 and Mercury 2?

Key differences include context window (1.0M 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 5 and Mercury 2?

Claude Opus 5 is developed by Anthropic and Mercury 2 is developed by Inception.

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