Home/Compare/Claude 3 Opus vs Claude 3.5 Sonnet

Claude 3 Opus vs Claude 3.5 Sonnet

Claude 3 Opus for highest-tier reasoning tasks, Claude 3.5 Sonnet for best value in the Claude family.

Pricing source: live OpenRouter model catalog (`/api/v1/models`).

Model A

Claude 3 Opus

AnthropicText + Vision
Context Window200K
Knowledge CutoffUnknown
Open model page
Model B

Claude 3.5 Sonnet

AnthropicText + Vision
Context Window200K
Knowledge CutoffUnknown
Open model page

Editorial Verdict

Claude 3 Opus is Anthropic's ceiling model; Claude 3.5 Sonnet is the best value for most production tasks.

Claude 3 Opus is Anthropic's highest capability model; Claude 3.5 Sonnet is their best value model with nearly the same capability on most tasks. For maximum quality on the hardest tasks, Claude 3 Opus wins. For everyday production workloads where quality is high but cost matters, Claude 3.5 Sonnet wins.

Claude 3 Opus
  • Highest benchmark scores on the most complex reasoning and analysis tasks
  • Better at maintaining coherence over extremely long conversations
  • Preferred for research-grade analysis and high-stakes decision support

Best for: Research-grade analysis and maximum quality on the hardest tasks

Claude 3.5 Sonnet
  • Nearly the same quality as Opus on most tasks at significantly lower cost
  • Faster inference with better price-to-performance ratio
  • Extended thinking mode available for complex tasks when needed

Best for: Cost-conscious production applications and everyday high-quality workloads

Pricing sourced from OpenRouter — updates as their catalog changes.

Pricing Comparison

All values pull from OpenRouter and update as their catalog changes.

MetricClaude 3 OpusClaude 3.5 SonnetWinner
Input (per 1M tokens)CustomCustomN/A
Output (per 1M tokens)CustomCustomN/A
Request feeN/AN/AN/A
Image feeN/AN/AN/A

Cost Estimator

Estimate monthly billing using real OpenRouter prices.

Claude 3 Opus Total

Variable

Claude 3.5 Sonnet Total

Variable
Savings unavailable (pricing not published for one model).

Capability Signals

Scores are directional estimates from model metadata — not official benchmark results.

Claude 3 OpusMMLU Signal (Reasoning)Claude 3.5 Sonnet
76%
69%
Claude 3 OpusHumanEval Signal (Coding)Claude 3.5 Sonnet
69%
69%
Claude 3 OpusAgentic Tooling SignalClaude 3.5 Sonnet
69%
69%
Claude 3 OpusMultimodal SignalClaude 3.5 Sonnet
78%
78%

Capabilities Matrix

Feature highlights for architecture and production fit.

Claude 3 Opus Strengths

  • Supports image inputs for multimodal analysis workflows.
  • Large context window for long documents and codebases.
  • Balanced general-purpose profile for chat, extraction, and automation tasks.

Claude 3.5 Sonnet Strengths

  • Supports image inputs for multimodal analysis workflows.
  • Large context window for long documents and codebases.
  • Balanced general-purpose profile for chat, extraction, and automation tasks.

API Implementation

Quick start snippets for each provider style.

Anthropic (Python)

import anthropic

client = anthropic.Anthropic()

message = client.messages.create(
  model="anthropic/claude-3-opus",
  max_tokens=1024,
  messages=[{"role": "user", "content": "Hello"}]
)

print(message.content)

Anthropic (Python)

import anthropic

client = anthropic.Anthropic()

message = client.messages.create(
  model="anthropic/claude-3.5-sonnet",
  max_tokens=1024,
  messages=[{"role": "user", "content": "Hello"}]
)

print(message.content)

Choose Claude 3 Opus when...

  • Your application includes visual reasoning and image understanding tasks.
  • You process large documents or code repositories in a single prompt.
  • You want a balanced default for mixed chat and workflow automation workloads.

Choose Claude 3.5 Sonnet when...

  • Your application includes visual reasoning and image understanding tasks.
  • You process large documents or code repositories in a single prompt.
  • You want a balanced default for mixed chat and workflow automation workloads.

Frequently Asked Questions

Practical checks before selecting a production model.

Which model is better for coding?

Coding preference depends on your stack and tool-calling needs. Compare the coding signal row, test with your repository tasks, and validate latency in your target region.

Which model is cheaper at scale?

Input and output token pricing can diverge by workload profile. Use the estimator with your monthly request count and token mix to get a realistic cost difference.

Are these official benchmark numbers?

Pricing is live from OpenRouter. Benchmark rows are ModelsAtlas metadata-based signals and should be treated as directional guidance, not official leaderboard scores.

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