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Claude Opus 5.5 vs o1-mini

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 10.0. o1-mini is 1.5x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 59.7 to 10.0, ranking #1 overall.

On price, o1-mini is roughly 1.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 5.5 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Opus 5.5

  • overall performance matters — it scores 59.7 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Sep 2026

Choose o1-mini

  • cost matters — it's about 1.5x cheaper per token

At a glance

The differences that matter most.

Core performance indexes
59.7
#1
10.0
#272
57.8
#1
10.3
#266
51.7
#1
14.4
#140
Cost, coverage & limits
Benchmark wins
Input price
$4.00 / M
$3.00 / M
Output price
$20.00 / M
$12.00 / M
Context window
1,000,000
128,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 5.5
o1-mini
42.5#5
10.9#248
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 6 for o1-mini

No common benchmarks found

Claude Opus 5.5 and o1-minidon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

o1-mini costs less

For input processing, Claude Opus 5.5 ($4.00/1M tokens) is 1.3x more expensive than o1-mini ($3.00/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 1.7x more expensive than o1-mini ($12.00/1M tokens).

In conclusion, Claude Opus 5.5 is more expensive than o1-mini.*

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

Lowest available price from all providers
Tue Sep 22 2026 • llm-stats.com
Anthropic
Claude Opus 5.5
Input tokens$4.00
Output tokens$20.00
Best providerAnthropic
OpenAI
o1-mini
Input tokens$3.00
Output tokens$12.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

Claude Opus 5.5 accepts 1,000,000 input tokens compared to o1-mini's 128,000 tokens. Claude Opus 5.5 can generate longer responses up to 128,000 tokens, while o1-mini is limited to 65,536 tokens.

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
OpenAI
o1-mini
Input128,000 tokens
Output65,536 tokens
Tue Sep 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Opus 5.5 supports multimodal inputs, whereas o1-mini does not.

Claude Opus 5.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 5.5

Text
Images
Audio
Video

o1-mini

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 5.5

Proprietary

Closed source

o1-mini

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while o1-mini was released on 2024-09-12.

Claude Opus 5.5 is 25 months newer than o1-mini.

Claude Opus 5.5

Sep 22, 2026

0 days ago

2.0yr newer
o1-mini

Sep 12, 2024

2.0 years ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a documented knowledge cutoff of 2026-06-01, while o1-mini's cutoff date is not specified.

We can confirm Claude Opus 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without o1-mini's cutoff date.

Claude Opus 5.5

Jun 2026

o1-mini

Provider Availability

Claude Opus 5.5 is available from Anthropic. o1-mini is available from OpenAI, Azure.

Claude Opus 5.5

anthropic logo
Anthropic
Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

o1-mini

openai logo
OpenAI
Input Price:Input: $3.00/1MOutput Price:Output: $12.00/1M
azure logo
Azure
Input Price:Input: $3.30/1MOutput Price:Output: $13.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and o1-mini side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
o1-mini
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs o1-mini.

Which is better, Claude Opus 5.5 or o1-mini?

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 10.0. Claude Opus 5.5 is made by Anthropic and o1-mini is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 5.5 compare to o1-mini in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. o1-mini scores HumanEval: 92.4%, MATH-500: 90.0%, MMLU: 85.2%, SuperGLUE: 75.0%, GPQA: 60.0%.

Is Claude Opus 5.5 cheaper than o1-mini?

o1-mini is 1.3x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. o1-mini costs $3.00/M input and $12.00/M output via openai.

What are the context window sizes for Claude Opus 5.5 and o1-mini?

Claude Opus 5.5 supports 1.0M tokens and o1-mini 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 5.5 and o1-mini?

Key differences include LLM Stats Score (59.7 vs 10.0), context window (1.0M vs 128K), input pricing ($4.00 vs $3.00/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and o1-mini?

Claude Opus 5.5 is developed by Anthropic and o1-mini is developed by OpenAI.