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Anthropic: Claude Opus 4.6 vs Anthropic: Claude Opus 4.5: Coding Performance with 10 Evaluators

In our latest evaluation of Coding Performance with 10 Evaluators, we compare Anthropic: Claude Opus 4.6 vs Anthropic: Claude Opus 4.5 to determine the superior model for development tasks.

Anthropic: Claude Opus 4.6

4.3

preference score

vs

Anthropic: Claude Opus 4.5

5.8

preference score

Judges ranked the responses in this Run against each other; the rank is mapped onto a 0–10 scale. It shows which response was preferred, not how good either one is — and it is not a percentage, a pass rate, or a check that the output was correct.

Sample size for this comparison was not recorded. Treat it as directional.

Evidence clarification: this article predates recorded sample provenance. Treat its conclusions as claims about the displayed examples; they do not establish general model superiority, verified correctness, or production suitability.

Key Findings

Top PerformerAnthropic: Claude Opus 4.5

Ranked #1 by our 10 evaluators for coding accuracy and instruction adherence.

Cost EfficiencyAnthropic: Claude Opus 4.5

Achieved a lower total cost for the evaluation suite compared to the 4.6 model.

ConsistencyAnthropic: Claude Opus 4.5

Maintained a higher score spread, indicating more reliable output across coding prompts.

Specifications

SpecAnthropic: Claude Opus 4.6Anthropic: Claude Opus 4.5
Provideranthropicanthropic
Context Length1.0M200K
Input Price (per 1M tokens)$5.00$5.00
Output Price (per 1M tokens)$25.00$25.00
Max Output Tokens128,00064,000
Tierfrontierfrontier

Our Verdict

Anthropic: Claude Opus 4.5 clearly outperforms the 4.6 variant in our coding-specific benchmark, securing the top rank for both accuracy and instruction following. Developers seeking the most reliable coding assistant should prioritize the 4.5 model, which also proves to be more cost-effective based on our evaluation data.

Overview

As LLM capabilities evolve, developers are increasingly focused on finding the most reliable model for complex programming tasks. In this PeerLM comparative study, we analyze Anthropic: Claude Opus 4.6 vs Anthropic: Claude Opus 4.5, specifically focusing on their Coding Performance with 10 Evaluators. This evaluation provides a direct look at how these iterations perform under real-world pressure, prioritizing accuracy and the ability to follow complex coding instructions.

Benchmark Results

Our evaluation utilized 10 independent evaluators to rank the performance of both models across a series of coding prompts. The results highlight a clear distinction in capability between the two versions.

ModelOverall ScoreRank
Anthropic: Claude Opus 4.55.751
Anthropic: Claude Opus 4.64.252

Criteria Breakdown

The evaluation focused on two primary pillars of coding excellence: Accuracy and Instruction Following. In a comparative, ranking-based assessment, these scores represent the consensus of our 10 subject matter experts.

  • Accuracy: Evaluators assessed how well the models generated syntactically correct and logically sound code. Claude Opus 4.5 secured the top position, demonstrating a higher degree of reliability in edge-case handling.
  • Instruction Following: This criterion measured the model's ability to adhere to specific formatting requirements and library constraints. Again, Claude Opus 4.5 outperformed the 4.6 iteration in this specific coding suite.

Cost & Latency

Performance is only one part of the equation; operational efficiency is critical for production-level coding assistants. Here is how the models compare in terms of cost and speed:

ModelAvg Latency (ms)Total Cost (USD)Avg Completion Tokens
Anthropic: Claude Opus 4.513960.03434296
Anthropic: Claude Opus 4.60*0.040785360

*Latency tracking for the 4.6 variant was unavailable during this specific evaluation run.

Use Cases

Anthropic: Claude Opus 4.5 is currently the superior choice for high-stakes coding projects where accuracy and strict adherence to architectural guidelines are non-negotiable. Its performance in this benchmark suggests it is better suited for complex refactoring and feature implementation tasks.

Anthropic: Claude Opus 4.6, while ranking second in this specific coding suite, generates longer responses on average. This may make it suitable for tasks requiring verbose documentation or extensive code explanation, though it may require more rigorous verification compared to its predecessor.

Verdict

Based on our Coding Performance with 10 Evaluators, Anthropic: Claude Opus 4.5 is the recommended model for developers requiring maximum reliability. With a score of 5.75 compared to 4.25, it demonstrates a more consistent ability to handle coding challenges effectively. While the 4.6 iteration offers different output characteristics, the 4.5 version currently leads the leaderboard in both precision and cost-efficiency.

Backed by real data

View the Full Evaluation Report

See every response, score, and evaluator judgment behind this comparison. All data from PeerLM's blind evaluation pipeline.

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Methodology

Evaluated using PeerLM's blind evaluation pipeline with 4 responses per model across 2 criteria.