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Claude Opus 5 vs o3

Claude Opus 5 leads the LLM Stats Score 54.6 to 31.1. o3 is 2.9x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Opus 5 leads the overall LLM Stats Score 54.6 to 31.1, ranking #5 overall.

In the 2 individual benchmarks reported for both models, Claude Opus 5 wins 2; this is a narrower head-to-head signal than the composite indexes.

On price, o3 is roughly 2.9x 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.

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

Choose Claude Opus 5

  • overall performance matters — it scores 54.6 and ranks #5 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 2 of 2 exact shared results
  • 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 o3

  • cost matters — it's about 2.9x cheaper per token

At a glance

The differences that matter most.

Core performance indexes
54.6
#5
31.1
#113
53.6
#4
30.8
#114
42.0
#9
14.9
#130
39.5
#7
4.0
#159
Cost, coverage & limits
Benchmark wins
2 of 2
0 of 2
Input price
$5.00 / M
$2.00 / M
Output price
$25.00 / M
$8.00 / M
Context window
1,000,000
200,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Claude Opus 5
o3
37.9#4
21.6#59
27.6#23
11.0#117
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

13 reported for Claude Opus 5 · 22 for o3

2 shared

Claude Opus 5 outperforms in 2 benchmarks (BrowseComp, Humanity's Last Exam), while o3 is better at 0 benchmarks.

Claude Opus 5 significantly outperforms across most benchmarks.

Sun Sep 20 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

o3 costs less

For input processing, Claude Opus 5 ($5.00/1M tokens) is 2.5x more expensive than o3 ($2.00/1M tokens).

For output processing, Claude Opus 5 ($25.00/1M tokens) is 3.1x more expensive than o3 ($8.00/1M tokens).

In conclusion, Claude Opus 5 is more expensive than o3.*

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

Lowest available price from all providers
Sun Sep 20 2026 • llm-stats.com
Anthropic
Claude Opus 5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
o3
Input tokens$2.00
Output tokens$8.00
Best providerOpenAI
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 o3's 200,000 tokens. Claude Opus 5 can generate longer responses up to 128,000 tokens, while o3 is limited to 100,000 tokens.

Anthropic
Claude Opus 5
Input1,000,000 tokens
Output128,000 tokens
OpenAI
o3
Input200,000 tokens
Output100,000 tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5 and o3 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 5

Text
Images
Audio
Video

o3

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

o3

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5 was released on 2026-07-24, while o3 was released on 2025-04-16.

Claude Opus 5 is 15 months newer than o3.

Claude Opus 5

Jul 24, 2026

1 months ago

1.3yr newer
o3

Apr 16, 2025

1.4 years ago

Knowledge Cutoff

When training data ends

o3 has a documented knowledge cutoff of 2024-05-31, while Claude Opus 5's cutoff date is not specified.

We can confirm o3's training data extends to 2024-05-31, but cannot make a direct comparison without Claude Opus 5's cutoff date.

Claude Opus 5

o3

May 2024

Provider Availability

Claude Opus 5 is available from Anthropic, DeepInfra. o3 is available from OpenAI.

Claude Opus 5

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

o3

openai logo
OpenAI
Input Price:Input: $2.00/1MOutput Price:Output: $8.00/1M
* 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 and o3 side-by-side, then vote on the output you prefer.

Claude Opus 5
✓ Preferred
o3
Open in Playground

FAQ

Common questions about Claude Opus 5 vs o3.

Which is better, Claude Opus 5 or o3?

Claude Opus 5 leads the LLM Stats Score 54.6 to 31.1. Claude Opus 5 is made by Anthropic and o3 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 compare to o3 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%. o3 scores COLLIE: 98.4%, AIME 2024: 91.6%, ARC-AGI: 88.0%, MathVista: 86.8%, AIME 2025: 86.4%.

Is Claude Opus 5 cheaper than o3?

o3 is 2.5x cheaper for input tokens. Claude Opus 5 costs $5.00/M input and $25.00/M output via anthropic. o3 costs $2.00/M input and $8.00/M output via openai.

What are the context window sizes for Claude Opus 5 and o3?

Claude Opus 5 supports 1.0M tokens and o3 supports 200K 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 o3?

Key differences include LLM Stats Score (54.6 vs 31.1), context window (1.0M vs 200K), input pricing ($5.00 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5 and o3?

Claude Opus 5 is developed by Anthropic and o3 is developed by OpenAI.